netbox/netbox/dcim/tests/test_cablepaths2.py

from unittest import skip

from circuits.models import Circuit, CircuitTermination, ProviderNetwork
from dcim.choices import CableLengthUnitChoices, CableProfileChoices
from dcim.models import *
from dcim.svg import CableTraceSVG
from dcim.tests.utils import BaseCablePathTestCase
from netbox.choices import DistanceUnitChoices


class CablePathTestCase(BaseCablePathTestCase):
    """
    Test the creation of CablePaths for Cables with different profiles applied.

    Tests are numbered as follows:
        1XX: Test direct connections using each profile
        2XX: Topology tests replicated from the legacy test case and adapted to use profiles
        3XX: Dynamic port mapping, profile and termination changes
    """

    def test_101_cable_profile_single_1c1p(self):
        """
        [IF1] --C1-- [IF2]

        Cable profile: Single connector, single position
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]

        # Create cable 1
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            a_terminations=[interfaces[0]],
            b_terminations=[interfaces[1]],
        )
        cable1.clean()
        cable1.save()

        path1 = self.assertPathExists(
            (interfaces[0], cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)
        interfaces[0].refresh_from_db()
        interfaces[1].refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[0].cable_positions, [1])
        self.assertEqual(interfaces[1].cable_connector, 1)
        self.assertEqual(interfaces[1].cable_positions, [1])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

        # Delete cable 1
        cable1.delete()

        # Check that all CablePaths have been deleted
        self.assertEqual(CablePath.objects.count(), 0)

    def test_102_cable_profile_single_1c2p(self):
        """
        [IF1] --C1-- [FP1][RP1] --C3-- [RP2][FP3] --C4-- [IF3]
        [IF2] --C2-- [FP2]                  [FP4] --C5-- [IF4]

        Cable profile: Single connector, multiple positions
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=2),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
            FrontPort.objects.create(device=self.device, name='Front Port 3'),
            FrontPort.objects.create(device=self.device, name='Front Port 4'),
        ]
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=front_ports[0],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[1],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[2],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[3],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=2,
            ),
        ])

        # Create cables
        cable1 = Cable(
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            a_terminations=[interfaces[1]],
            b_terminations=[front_ports[1]],
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[rear_ports[0]],
            b_terminations=[rear_ports[1]],
        )
        cable3.clean()
        cable3.save()
        cable4 = Cable(
            a_terminations=[interfaces[2]],
            b_terminations=[front_ports[2]],
        )
        cable4.clean()
        cable4.save()
        cable5 = Cable(
            a_terminations=[interfaces[3]],
            b_terminations=[front_ports[3]],
        )
        cable5.clean()
        cable5.save()

        path1 = self.assertPathExists(
            (
                interfaces[0], cable1, front_ports[0], rear_ports[0], cable3, rear_ports[1], front_ports[2], cable4,
                interfaces[2],
            ),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (
                interfaces[1], cable2, front_ports[1], rear_ports[0], cable3, rear_ports[1], front_ports[3], cable5,
                interfaces[3],
            ),
            is_complete=True,
            is_active=True
        )
        path3 = self.assertPathExists(
            (
                interfaces[2], cable4, front_ports[2], rear_ports[1], cable3, rear_ports[0], front_ports[0], cable1,
                interfaces[0],
            ),
            is_complete=True,
            is_active=True
        )
        path4 = self.assertPathExists(
            (
                interfaces[3], cable5, front_ports[3], rear_ports[1], cable3, rear_ports[0], front_ports[1], cable2,
                interfaces[1],
            ),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 4)
        for iface in interfaces:
            iface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)
        self.assertPathIsSet(interfaces[3], path4)
        for rear_port in rear_ports:
            rear_port.refresh_from_db()
        self.assertEqual(rear_ports[0].cable_connector, 1)
        self.assertEqual(rear_ports[0].cable_positions, [1, 2])
        self.assertEqual(rear_ports[1].cable_connector, 1)
        self.assertEqual(rear_ports[1].cable_positions, [1, 2])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_103_cable_profile_trunk_2c1p(self):
        """
        [IF1] --C1-- [IF3]
        [IF2]        [IF4]

        Cable profile: Multiple connectors, single position
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]

        # Create cable 1
        cable1 = Cable(
            profile=CableProfileChoices.TRUNK_2C1P,
            a_terminations=[interfaces[0], interfaces[1]],
            b_terminations=[interfaces[2], interfaces[3]],
        )
        cable1.clean()
        cable1.save()

        path1 = self.assertPathExists(
            (interfaces[0], cable1, interfaces[2]),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable1, interfaces[3]),
            is_complete=True,
            is_active=True
        )
        path3 = self.assertPathExists(
            (interfaces[2], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        path4 = self.assertPathExists(
            (interfaces[3], cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 4)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)
        self.assertPathIsSet(interfaces[3], path4)
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[0].cable_positions, [1])
        self.assertEqual(interfaces[1].cable_connector, 2)
        self.assertEqual(interfaces[1].cable_positions, [1])
        self.assertEqual(interfaces[2].cable_connector, 1)
        self.assertEqual(interfaces[2].cable_positions, [1])
        self.assertEqual(interfaces[3].cable_connector, 2)
        self.assertEqual(interfaces[3].cable_positions, [1])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

        # Delete cable 1
        cable1.delete()

        # Check that all CablePaths have been deleted
        self.assertEqual(CablePath.objects.count(), 0)

    def test_104_cable_profile_trunk_2c2p(self):
        """
        [IF1] --C1-- [FP1][RP1] --C9-- [RP3][FP5] --C5-- [IF5]
        [IF2] --C2-- [FP2]                  [FP6] --C6-- [IF6]
        [IF3] --C3-- [FP3][RP2]        [RP4][FP7] --C7-- [IF7]
        [IF4] --C4-- [FP4]                  [FP8] --C8-- [IF8]

        Cable profile: Multiple connectors, multiple positions
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
            Interface.objects.create(device=self.device, name='Interface 5'),
            Interface.objects.create(device=self.device, name='Interface 6'),
            Interface.objects.create(device=self.device, name='Interface 7'),
            Interface.objects.create(device=self.device, name='Interface 8'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 3', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 4', positions=2),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
            FrontPort.objects.create(device=self.device, name='Front Port 3'),
            FrontPort.objects.create(device=self.device, name='Front Port 4'),
            FrontPort.objects.create(device=self.device, name='Front Port 5'),
            FrontPort.objects.create(device=self.device, name='Front Port 6'),
            FrontPort.objects.create(device=self.device, name='Front Port 7'),
            FrontPort.objects.create(device=self.device, name='Front Port 8'),
        ]
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=front_ports[0],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[1],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[2],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[3],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[4],
                front_port_position=1,
                rear_port=rear_ports[2],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[5],
                front_port_position=1,
                rear_port=rear_ports[2],
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[6],
                front_port_position=1,
                rear_port=rear_ports[3],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[7],
                front_port_position=1,
                rear_port=rear_ports[3],
                rear_port_position=2,
            ),
        ])

        # Create cables
        cable1 = Cable(a_terminations=[interfaces[0]], b_terminations=[front_ports[0]])
        cable1.clean()
        cable1.save()
        cable2 = Cable(a_terminations=[interfaces[1]], b_terminations=[front_ports[1]])
        cable2.clean()
        cable2.save()
        cable3 = Cable(a_terminations=[interfaces[2]], b_terminations=[front_ports[2]])
        cable3.clean()
        cable3.save()
        cable4 = Cable(a_terminations=[interfaces[3]], b_terminations=[front_ports[3]])
        cable4.clean()
        cable4.save()
        cable5 = Cable(a_terminations=[interfaces[4]], b_terminations=[front_ports[4]])
        cable5.clean()
        cable5.save()
        cable6 = Cable(a_terminations=[interfaces[5]], b_terminations=[front_ports[5]])
        cable6.clean()
        cable6.save()
        cable7 = Cable(a_terminations=[interfaces[6]], b_terminations=[front_ports[6]])
        cable7.clean()
        cable7.save()
        cable8 = Cable(a_terminations=[interfaces[7]], b_terminations=[front_ports[7]])
        cable8.clean()
        cable8.save()
        cable9 = Cable(
            profile=CableProfileChoices.TRUNK_2C2P,
            a_terminations=[rear_ports[0], rear_ports[1]],
            b_terminations=[rear_ports[2], rear_ports[3]]
        )
        cable9.clean()
        cable9.save()

        path1 = self.assertPathExists(
            (
                interfaces[0], cable1, front_ports[0], rear_ports[0], cable9, rear_ports[2], front_ports[4], cable5,
                interfaces[4],
            ),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (
                interfaces[1], cable2, front_ports[1], rear_ports[0], cable9, rear_ports[2], front_ports[5], cable6,
                interfaces[5],
            ),
            is_complete=True,
            is_active=True
        )
        path3 = self.assertPathExists(
            (
                interfaces[2], cable3, front_ports[2], rear_ports[1], cable9, rear_ports[3], front_ports[6], cable7,
                interfaces[6],
            ),
            is_complete=True,
            is_active=True
        )
        path4 = self.assertPathExists(
            (
                interfaces[3], cable4, front_ports[3], rear_ports[1], cable9, rear_ports[3], front_ports[7], cable8,
                interfaces[7],
            ),
            is_complete=True,
            is_active=True
        )
        path5 = self.assertPathExists(
            (
                interfaces[4], cable5, front_ports[4], rear_ports[2], cable9, rear_ports[0], front_ports[0], cable1,
                interfaces[0],
            ),
            is_complete=True,
            is_active=True
        )
        path6 = self.assertPathExists(
            (
                interfaces[5], cable6, front_ports[5], rear_ports[2], cable9, rear_ports[0], front_ports[1], cable2,
                interfaces[1],
            ),
            is_complete=True,
            is_active=True
        )
        path7 = self.assertPathExists(
            (
                interfaces[6], cable7, front_ports[6], rear_ports[3], cable9, rear_ports[1], front_ports[2], cable3,
                interfaces[2],
            ),
            is_complete=True,
            is_active=True
        )
        path8 = self.assertPathExists(
            (
                interfaces[7], cable8, front_ports[7], rear_ports[3], cable9, rear_ports[1], front_ports[3], cable4,
                interfaces[3],
            ),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 8)
        for iface in interfaces:
            iface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)
        self.assertPathIsSet(interfaces[3], path4)
        self.assertPathIsSet(interfaces[4], path5)
        self.assertPathIsSet(interfaces[5], path6)
        self.assertPathIsSet(interfaces[6], path7)
        self.assertPathIsSet(interfaces[7], path8)
        for rear_port in rear_ports:
            rear_port.refresh_from_db()
        self.assertEqual(rear_ports[0].cable_connector, 1)
        self.assertEqual(rear_ports[0].cable_positions, [1, 2])
        self.assertEqual(rear_ports[1].cable_connector, 2)
        self.assertEqual(rear_ports[1].cable_positions, [1, 2])
        self.assertEqual(rear_ports[2].cable_connector, 1)
        self.assertEqual(rear_ports[2].cable_positions, [1, 2])
        self.assertEqual(rear_ports[3].cable_connector, 2)
        self.assertEqual(rear_ports[3].cable_positions, [1, 2])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_105_cable_profile_breakout(self):
        """
        [IF1] --C1-- [FP1][RP1] --C2-- [IF5]
        [IF2] --C3-- [FP2]             [IF6]
        [IF3] --C4-- [FP3]             [IF7]
        [IF4] --C5-- [FP4]             [IF8]

        Cable profile: 1:4 breakout
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
            Interface.objects.create(device=self.device, name='Interface 5'),
            Interface.objects.create(device=self.device, name='Interface 6'),
            Interface.objects.create(device=self.device, name='Interface 7'),
            Interface.objects.create(device=self.device, name='Interface 8'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
            FrontPort.objects.create(device=self.device, name='Front Port 3'),
            FrontPort.objects.create(device=self.device, name='Front Port 4'),
        ]
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=front_ports[0],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[1],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[2],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=3,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[3],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=4,
            ),
        ])

        # Create cables
        cable1 = Cable(a_terminations=[interfaces[0]], b_terminations=[front_ports[0]])
        cable1.clean()
        cable1.save()
        cable2 = Cable(a_terminations=[interfaces[1]], b_terminations=[front_ports[1]])
        cable2.clean()
        cable2.save()
        cable3 = Cable(a_terminations=[interfaces[2]], b_terminations=[front_ports[2]])
        cable3.clean()
        cable3.save()
        cable4 = Cable(a_terminations=[interfaces[3]], b_terminations=[front_ports[3]])
        cable4.clean()
        cable4.save()
        cable5 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[rear_ports[0]],
            b_terminations=interfaces[4:8],
        )
        cable5.clean()
        cable5.save()

        path1 = self.assertPathExists(
            (interfaces[0], cable1, front_ports[0], rear_ports[0], cable5, interfaces[4]),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable2, front_ports[1], rear_ports[0], cable5, interfaces[5]),
            is_complete=True,
            is_active=True
        )
        path3 = self.assertPathExists(
            (interfaces[2], cable3, front_ports[2], rear_ports[0], cable5, interfaces[6]),
            is_complete=True,
            is_active=True
        )
        path4 = self.assertPathExists(
            (interfaces[3], cable4, front_ports[3], rear_ports[0], cable5, interfaces[7]),
            is_complete=True,
            is_active=True
        )
        path5 = self.assertPathExists(
            (interfaces[4], cable5, rear_ports[0], front_ports[0], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        path6 = self.assertPathExists(
            (interfaces[5], cable5, rear_ports[0], front_ports[1], cable2, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        path7 = self.assertPathExists(
            (interfaces[6], cable5, rear_ports[0], front_ports[2], cable3, interfaces[2]),
            is_complete=True,
            is_active=True
        )
        path8 = self.assertPathExists(
            (interfaces[7], cable5, rear_ports[0], front_ports[3], cable4, interfaces[3]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 8)
        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)
        self.assertPathIsSet(interfaces[3], path4)
        self.assertPathIsSet(interfaces[4], path5)
        self.assertPathIsSet(interfaces[5], path6)
        self.assertPathIsSet(interfaces[6], path7)
        self.assertPathIsSet(interfaces[7], path8)
        self.assertEqual(interfaces[4].cable_connector, 1)
        self.assertEqual(interfaces[4].cable_positions, [1])
        self.assertEqual(interfaces[5].cable_connector, 2)
        self.assertEqual(interfaces[5].cable_positions, [1])
        self.assertEqual(interfaces[6].cable_connector, 3)
        self.assertEqual(interfaces[6].cable_positions, [1])
        self.assertEqual(interfaces[7].cable_connector, 4)
        self.assertEqual(interfaces[7].cable_positions, [1])
        rear_ports[0].refresh_from_db()
        self.assertEqual(rear_ports[0].cable_connector, 1)
        self.assertEqual(rear_ports[0].cable_positions, [1, 2, 3, 4])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_106_cable_profile_shuffle(self):
        """
        [IF1] --C1-- [FP1][RP1] --C17-- [RP3][FP9]  --C9--  [IF9]
        [IF2] --C2-- [FP2]                   [FP10] --C10-- [IF10]
        [IF3] --C3-- [FP3]                   [FP11] --C11-- [IF11]
        [IF4] --C4-- [FP4]                   [FP12] --C12-- [IF12]
        [IF5] --C5-- [FP5][RP2]         [RP4][FP13] --C13-- [IF9]
        [IF6] --C6-- [FP6]                   [FP14] --C14-- [IF10]
        [IF7] --C7-- [FP7]                   [FP15] --C15-- [IF11]
        [IF8] --C8-- [FP8]                   [FP16] --C16-- [IF12]

        Cable profile: Shuffle (2x2 MPO8)
        """
        interfaces = [
            # A side
            Interface.objects.create(device=self.device, name='Interface 1:1'),
            Interface.objects.create(device=self.device, name='Interface 1:2'),
            Interface.objects.create(device=self.device, name='Interface 1:3'),
            Interface.objects.create(device=self.device, name='Interface 1:4'),
            Interface.objects.create(device=self.device, name='Interface 2:1'),
            Interface.objects.create(device=self.device, name='Interface 2:2'),
            Interface.objects.create(device=self.device, name='Interface 2:3'),
            Interface.objects.create(device=self.device, name='Interface 2:4'),
            # B side
            Interface.objects.create(device=self.device, name='Interface 3:1'),
            Interface.objects.create(device=self.device, name='Interface 3:2'),
            Interface.objects.create(device=self.device, name='Interface 3:3'),
            Interface.objects.create(device=self.device, name='Interface 3:4'),
            Interface.objects.create(device=self.device, name='Interface 4:1'),
            Interface.objects.create(device=self.device, name='Interface 4:2'),
            Interface.objects.create(device=self.device, name='Interface 4:3'),
            Interface.objects.create(device=self.device, name='Interface 4:4'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=4),
            RearPort.objects.create(device=self.device, name='Rear Port 3', positions=4),
            RearPort.objects.create(device=self.device, name='Rear Port 4', positions=4),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
            FrontPort.objects.create(device=self.device, name='Front Port 3'),
            FrontPort.objects.create(device=self.device, name='Front Port 4'),
            FrontPort.objects.create(device=self.device, name='Front Port 5'),
            FrontPort.objects.create(device=self.device, name='Front Port 6'),
            FrontPort.objects.create(device=self.device, name='Front Port 7'),
            FrontPort.objects.create(device=self.device, name='Front Port 8'),
            FrontPort.objects.create(device=self.device, name='Front Port 9'),
            FrontPort.objects.create(device=self.device, name='Front Port 10'),
            FrontPort.objects.create(device=self.device, name='Front Port 11'),
            FrontPort.objects.create(device=self.device, name='Front Port 12'),
            FrontPort.objects.create(device=self.device, name='Front Port 13'),
            FrontPort.objects.create(device=self.device, name='Front Port 14'),
            FrontPort.objects.create(device=self.device, name='Front Port 15'),
            FrontPort.objects.create(device=self.device, name='Front Port 16'),
        ]
        port_mappings = []
        for i, front_port in enumerate(front_ports):
            port_mappings.append(
                PortMapping(
                    device=self.device,
                    front_port=front_ports[i],
                    front_port_position=1,
                    rear_port=rear_ports[int(i / 4)],
                    rear_port_position=(i % 4) + 1,
                ),
            )
        PortMapping.objects.bulk_create(port_mappings)

        # Create cables
        cables = []
        for interface, front_port in zip(interfaces, front_ports):
            cable = Cable(a_terminations=[interface], b_terminations=[front_port])
            cable.clean()
            cable.save()
            cables.append(cable)
        shuffle_cable = Cable(
            profile=CableProfileChoices.TRUNK_2C4P_SHUFFLE,
            a_terminations=rear_ports[0:2],
            b_terminations=rear_ports[2:4],
        )
        shuffle_cable.clean()
        shuffle_cable.save()

        paths = [
            # A-to-B paths
            self.assertPathExists(
                (
                    interfaces[0], cables[0], front_ports[0], rear_ports[0], shuffle_cable, rear_ports[2],
                    front_ports[8], cables[8], interfaces[8],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[1], cables[1], front_ports[1], rear_ports[0], shuffle_cable, rear_ports[2],
                    front_ports[9], cables[9], interfaces[9],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[2], cables[2], front_ports[2], rear_ports[0], shuffle_cable, rear_ports[3],
                    front_ports[12], cables[12], interfaces[12],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[3], cables[3], front_ports[3], rear_ports[0], shuffle_cable, rear_ports[3],
                    front_ports[13], cables[13], interfaces[13],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[4], cables[4], front_ports[4], rear_ports[1], shuffle_cable, rear_ports[2],
                    front_ports[10], cables[10], interfaces[10],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[5], cables[5], front_ports[5], rear_ports[1], shuffle_cable, rear_ports[2],
                    front_ports[11], cables[11], interfaces[11],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[6], cables[6], front_ports[6], rear_ports[1], shuffle_cable, rear_ports[3],
                    front_ports[14], cables[14], interfaces[14],
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interfaces[7], cables[7], front_ports[7], rear_ports[1], shuffle_cable, rear_ports[3],
                    front_ports[15], cables[15], interfaces[15],
                ),
                is_complete=True,
                is_active=True
            ),
        ]
        self.assertEqual(CablePath.objects.count(), len(paths) * 2)

        for i, (interface, path) in enumerate(zip(interfaces, paths)):
            interface.refresh_from_db()
            self.assertPathIsSet(interface, path)
        for i, rear_port in enumerate(rear_ports):
            rear_port.refresh_from_db()
            self.assertEqual(rear_port.cable_connector, (i % 2) + 1)
            self.assertEqual(rear_port.cable_positions, [1, 2, 3, 4])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_107_duplex_interface_profiled_patch_through_trunk_with_splices(self):
        """
        Tests that a duplex interface (cable_positions=[1,2]) traces both positions through
        profiled cables and splice pass-throughs, producing a single CablePath with both
        strands visible.

        [IF1] -C1(1C2P)- [FP1(p=2)][RP1(p=2)] -C2(1C2P)- [RP2(p=2)]
        [FP2] -C3- [FP4][RP3(p=2)] -C4(1C2P)- [RP4(p=2)][FP6(p=2)]
        -C5(1C2P)- [IF2]  /  [FP3] -C6- [FP5]

        Cable profiles: C1=1C2P, C2=1C2P, C3/C6=unprofiled splices, C4=1C2P, C5=1C2P
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 3', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 4', positions=2),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1', positions=2),  # Panel A duplex
            FrontPort.objects.create(device=self.device, name='Front Port 2'),               # Splice A strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 3'),               # Splice A strand 2
            FrontPort.objects.create(device=self.device, name='Front Port 4'),               # Splice B strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 5'),               # Splice B strand 2
            FrontPort.objects.create(device=self.device, name='Front Port 6', positions=2),  # Panel B duplex
        ]
        PortMapping.objects.bulk_create([
            # Panel A: duplex FP1(pos=2) -> RP1(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=1,
                rear_port=rear_ports[0], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=2,
                rear_port=rear_ports[0], rear_port_position=2,
            ),
            # Splice A: FP2, FP3 -> RP2(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=1,
                rear_port=rear_ports[1], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[2], front_port_position=1,
                rear_port=rear_ports[1], rear_port_position=2,
            ),
            # Splice B: FP4, FP5 -> RP3(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[3], front_port_position=1,
                rear_port=rear_ports[2], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[4], front_port_position=1,
                rear_port=rear_ports[2], rear_port_position=2,
            ),
            # Panel B: duplex FP6(pos=2) -> RP4(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[5], front_port_position=1,
                rear_port=rear_ports[3], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[5], front_port_position=2,
                rear_port=rear_ports[3], rear_port_position=2,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[rear_ports[0]],
            b_terminations=[rear_ports[1]],
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            a_terminations=[front_ports[1]],
            b_terminations=[front_ports[3]],
        )
        cable3.clean()
        cable3.save()
        cable4 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[rear_ports[2]],
            b_terminations=[rear_ports[3]],
        )
        cable4.clean()
        cable4.save()
        cable5 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[front_ports[5]],
            b_terminations=[interfaces[1]],
        )
        cable5.clean()
        cable5.save()
        cable6 = Cable(
            a_terminations=[front_ports[2]],
            b_terminations=[front_ports[4]],
        )
        cable6.clean()
        cable6.save()

        # Verify forward path: IF1 -> IF2 (both strands through splice)
        self.assertPathExists(
            (
                interfaces[0], cable1, front_ports[0],
                rear_ports[0], cable2, rear_ports[1],
                [front_ports[1], front_ports[2]], [cable3, cable6], [front_ports[3], front_ports[4]],
                rear_ports[2], cable4, rear_ports[3],
                front_ports[5], cable5, interfaces[1],
            ),
            is_complete=True,
            is_active=True
        )
        # Verify reverse path: IF2 -> IF1
        self.assertPathExists(
            (
                interfaces[1], cable5, front_ports[5],
                rear_ports[3], cable4, rear_ports[2],
                [front_ports[3], front_ports[4]], [cable3, cable6], [front_ports[1], front_ports[2]],
                rear_ports[1], cable2, rear_ports[0],
                front_ports[0], cable1, interfaces[0],
            ),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)

        # Verify cable positions on interfaces
        for iface in interfaces:
            iface.refresh_from_db()
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[0].cable_positions, [1, 2])
        self.assertEqual(interfaces[1].cable_connector, 1)
        self.assertEqual(interfaces[1].cable_positions, [1, 2])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_108_single_interface_two_frontports_unprofiled_through_trunk_with_splices(self):
        """
        Tests that positions seeded by PortMapping (not cable_positions) are preserved
        when crossing profiled cables.

        [IF1] -C1- [FP1,FP2][RP1(p=2)] -C2(1C2P)- [RP2(p=2)]
        [FP3] -C3- [FP5][RP3(p=2)] -C4(1C2P)- [RP4(p=2)]
        [FP7,FP8] -C5- [IF2]  /  [FP4] -C6- [FP6]

        PortMappings: FP1->RP1p1, FP2->RP1p2, FP3->RP2p1, FP4->RP2p2,
                      FP5->RP3p1, FP6->RP3p2, FP7->RP4p1, FP8->RP4p2

        C1 is unprofiled (1 IF -> 2 FPs), C2/C4 are 1C2P trunks,
        C3/C6 are unprofiled splices, C5 is unprofiled (2 FPs -> 1 IF).
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 3', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 4', positions=2),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),  # Panel A strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 2'),  # Panel A strand 2
            FrontPort.objects.create(device=self.device, name='Front Port 3'),  # Splice A strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 4'),  # Splice A strand 2
            FrontPort.objects.create(device=self.device, name='Front Port 5'),  # Splice B strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 6'),  # Splice B strand 2
            FrontPort.objects.create(device=self.device, name='Front Port 7'),  # Panel B strand 1
            FrontPort.objects.create(device=self.device, name='Front Port 8'),  # Panel B strand 2
        ]
        PortMapping.objects.bulk_create([
            # Panel A: FP1, FP2 -> RP1(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=1,
                rear_port=rear_ports[0], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=1,
                rear_port=rear_ports[0], rear_port_position=2,
            ),
            # Splice A: FP3, FP4 -> RP2(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[2], front_port_position=1,
                rear_port=rear_ports[1], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[3], front_port_position=1,
                rear_port=rear_ports[1], rear_port_position=2,
            ),
            # Splice B: FP5, FP6 -> RP3(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[4], front_port_position=1,
                rear_port=rear_ports[2], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[5], front_port_position=1,
                rear_port=rear_ports[2], rear_port_position=2,
            ),
            # Panel B: FP7, FP8 -> RP4(pos=2)
            PortMapping(
                device=self.device, front_port=front_ports[6], front_port_position=1,
                rear_port=rear_ports[3], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[7], front_port_position=1,
                rear_port=rear_ports[3], rear_port_position=2,
            ),
        ])

        # Create cables
        cable1 = Cable(
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0], front_ports[1]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[rear_ports[0]],
            b_terminations=[rear_ports[1]],
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            a_terminations=[front_ports[2]],
            b_terminations=[front_ports[4]],
        )
        cable3.clean()
        cable3.save()
        cable4 = Cable(
            profile=CableProfileChoices.SINGLE_1C2P,
            a_terminations=[rear_ports[2]],
            b_terminations=[rear_ports[3]],
        )
        cable4.clean()
        cable4.save()
        cable5 = Cable(
            a_terminations=[front_ports[6], front_ports[7]],
            b_terminations=[interfaces[1]],
        )
        cable5.clean()
        cable5.save()
        cable6 = Cable(
            a_terminations=[front_ports[3]],
            b_terminations=[front_ports[5]],
        )
        cable6.clean()
        cable6.save()

        # Verify forward path: IF1 -> IF2 (both strands through splice)
        self.assertPathExists(
            (
                interfaces[0], cable1, [front_ports[0], front_ports[1]],
                rear_ports[0], cable2, rear_ports[1],
                [front_ports[2], front_ports[3]], [cable3, cable6], [front_ports[4], front_ports[5]],
                rear_ports[2], cable4, rear_ports[3],
                [front_ports[6], front_ports[7]], cable5, interfaces[1],
            ),
            is_complete=True,
            is_active=True
        )
        # Verify reverse path: IF2 -> IF1
        self.assertPathExists(
            (
                interfaces[1], cable5, [front_ports[6], front_ports[7]],
                rear_ports[3], cable4, rear_ports[2],
                [front_ports[4], front_ports[5]], [cable3, cable6], [front_ports[2], front_ports[3]],
                rear_ports[1], cable2, rear_ports[0],
                [front_ports[0], front_ports[1]], cable1, interfaces[0],
            ),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)

        # Verify cable positions are not set (unprofiled patch cables)
        for iface in interfaces:
            iface.refresh_from_db()
        self.assertIsNone(interfaces[0].cable_connector)
        self.assertIsNone(interfaces[0].cable_positions)
        self.assertIsNone(interfaces[1].cable_connector)
        self.assertIsNone(interfaces[1].cable_positions)

    def test_109_multiconnector_trunk_through_patch_panel(self):
        """
        Tests that a 4-position interface traces correctly through a patch panel
        that fans out to both connectors of a Trunk2C2P cable.

        [IF1] --C1(1C4P)-- [FP1(p=4)][RP1(p=2)] --C3(Trunk2C2P)-- [RP3(p=2)][FP5(p=4)] --C5(1C4P)-- [IF2]
                                      [RP2(p=2)]                    [RP4(p=2)]

        PortMappings (Panel A): FP1p1->RP1p1, FP1p2->RP1p2, FP1p3->RP2p1, FP1p4->RP2p2
        PortMappings (Panel B): FP5p1->RP3p1, FP5p2->RP3p2, FP5p3->RP4p1, FP5p4->RP4p2
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 2', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 3', positions=2),
            RearPort.objects.create(device=self.device, name='Rear Port 4', positions=2),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1', positions=4),
            FrontPort.objects.create(device=self.device, name='Front Port 5', positions=4),
        ]
        PortMapping.objects.bulk_create([
            # Panel A: FP1(p=4) -> RP1(p=2) and RP2(p=2)
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=1,
                rear_port=rear_ports[0], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=2,
                rear_port=rear_ports[0], rear_port_position=2,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=3,
                rear_port=rear_ports[1], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[0], front_port_position=4,
                rear_port=rear_ports[1], rear_port_position=2,
            ),
            # Panel B: FP5(p=4) -> RP3(p=2) and RP4(p=2)
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=1,
                rear_port=rear_ports[2], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=2,
                rear_port=rear_ports[2], rear_port_position=2,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=3,
                rear_port=rear_ports[3], rear_port_position=1,
            ),
            PortMapping(
                device=self.device, front_port=front_ports[1], front_port_position=4,
                rear_port=rear_ports[3], rear_port_position=2,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C4P,
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0]],
        )
        cable1.clean()
        cable1.save()
        cable3 = Cable(
            profile=CableProfileChoices.TRUNK_2C2P,
            a_terminations=[rear_ports[0], rear_ports[1]],
            b_terminations=[rear_ports[2], rear_ports[3]],
        )
        cable3.clean()
        cable3.save()
        cable5 = Cable(
            profile=CableProfileChoices.SINGLE_1C4P,
            a_terminations=[front_ports[1]],
            b_terminations=[interfaces[1]],
        )
        cable5.clean()
        cable5.save()

        # Verify forward path: IF1 -> IF2 (all 4 positions through trunk)
        self.assertPathExists(
            (
                interfaces[0], cable1, front_ports[0],
                [rear_ports[0], rear_ports[1]], cable3, [rear_ports[2], rear_ports[3]],
                front_ports[1], cable5, interfaces[1],
            ),
            is_complete=True,
            is_active=True
        )
        # Verify reverse path: IF2 -> IF1
        self.assertPathExists(
            (
                interfaces[1], cable5, front_ports[1],
                [rear_ports[2], rear_ports[3]], cable3, [rear_ports[0], rear_ports[1]],
                front_ports[0], cable1, interfaces[0],
            ),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)

        # Verify cable positions
        for iface in interfaces:
            iface.refresh_from_db()
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[0].cable_positions, [1, 2, 3, 4])
        self.assertEqual(interfaces[1].cable_connector, 1)
        self.assertEqual(interfaces[1].cable_positions, [1, 2, 3, 4])

        # Verify rear port connector assignments
        for rp in rear_ports:
            rp.refresh_from_db()
        self.assertEqual(rear_ports[0].cable_connector, 1)
        self.assertEqual(rear_ports[0].cable_positions, [1, 2])
        self.assertEqual(rear_ports[1].cable_connector, 2)
        self.assertEqual(rear_ports[1].cable_positions, [1, 2])
        self.assertEqual(rear_ports[2].cable_connector, 1)
        self.assertEqual(rear_ports[2].cable_positions, [1, 2])
        self.assertEqual(rear_ports[3].cable_connector, 2)
        self.assertEqual(rear_ports[3].cable_positions, [1, 2])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_110_partial_termination_profiled_trunk(self):
        """
        Tests that tracing through a partially terminated profiled cable
        produces a complete path for the connected pair and an incomplete
        path for the unconnected pair, without errors. Also verifies that
        attaching the missing termination completes the previously incomplete path.

        [IF1] --C1-- [IF3]
        [IF2]        (empty)

        Cable profile: Trunk 2C1P with only one B-side termination.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
        ]

        # Create a 2-connector trunk cable with both A-side connectors
        # populated but only one B-side connector terminated.
        cable1 = Cable(
            profile=CableProfileChoices.TRUNK_2C1P,
            a_terminations=[interfaces[0], interfaces[1]],
            b_terminations=[interfaces[2]],
        )
        cable1.clean()
        cable1.save()

        # IF1 (connector 1) → IF3 (connector 1): complete path
        path1 = self.assertPathExists(
            (interfaces[0], cable1, interfaces[2]),
            is_complete=True,
            is_active=True,
        )

        # IF3 (connector 1) → IF1 (connector 1): complete path (reverse)
        path2 = self.assertPathExists(
            (interfaces[2], cable1, interfaces[0]),
            is_complete=True,
            is_active=True,
        )

        # IF2 (connector 2) has no B-side peer.
        # Tracing should stop at this segment, and the resulting path
        # should remain incomplete.
        # Verify via the origin's _path reference rather than matching
        # the exact path shape directly.
        interfaces[1].refresh_from_db()
        self.assertIsNotNone(interfaces[1]._path_id)
        path3 = CablePath.objects.get(pk=interfaces[1]._path_id)
        self.assertFalse(path3.is_complete)
        self.assertTrue(path3.is_active)

        for iface in interfaces:
            iface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[2], path2)
        self.assertPathIsSet(interfaces[1], path3)

        # Verify connector/position assignments
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[0].cable_positions, [1])
        self.assertEqual(interfaces[1].cable_connector, 2)
        self.assertEqual(interfaces[1].cable_positions, [1])
        self.assertEqual(interfaces[2].cable_connector, 1)
        self.assertEqual(interfaces[2].cable_positions, [1])

        # Now attach the missing B-side termination and verify the
        # previously incomplete path becomes complete.
        interface4 = Interface.objects.create(device=self.device, name='Interface 4')
        cable1.b_terminations = [interfaces[2], interface4]
        cable1.clean()
        cable1.save()

        path4 = self.assertPathExists(
            (interfaces[1], cable1, interface4),
            is_complete=True,
            is_active=True,
        )
        path5 = self.assertPathExists(
            (interface4, cable1, interfaces[1]),
            is_complete=True,
            is_active=True,
        )

        interfaces[1].refresh_from_db()
        interface4.refresh_from_db()
        self.assertPathIsSet(interfaces[1], path4)
        self.assertPathIsSet(interface4, path5)
        self.assertEqual(interface4.cable_connector, 2)
        self.assertEqual(interface4.cable_positions, [1])

    def test_202_single_path_via_pass_through_with_breakouts(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C2-- [IF3]
        [IF2]                           [IF4]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=4)
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1', positions=4)
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=1,
                rear_port=rearport1,
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=2,
                rear_port=rearport1,
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=3,
                rear_port=rearport1,
                rear_port_position=3,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=4,
                rear_port=rearport1,
                rear_port_position=4,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[frontport1],
            b_terminations=[interfaces[0], interfaces[1]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[rearport1],
            b_terminations=[interfaces[2], interfaces[3]]
        )
        cable2.clean()
        cable2.save()

        paths = [
            self.assertPathExists(
                (interfaces[0], cable1, frontport1, rearport1, cable2, interfaces[2]),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (interfaces[1], cable1, frontport1, rearport1, cable2, interfaces[3]),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (interfaces[2], cable2, rearport1, frontport1, cable1, interfaces[0]),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (interfaces[3], cable2, rearport1, frontport1, cable1, interfaces[1]),
                is_complete=True,
                is_active=True
            ),
        ]
        self.assertEqual(CablePath.objects.count(), 4)
        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], paths[0])
        self.assertPathIsSet(interfaces[1], paths[1])
        self.assertPathIsSet(interfaces[2], paths[2])
        self.assertPathIsSet(interfaces[3], paths[3])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_204_multiple_paths_via_pass_through_with_breakouts(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C3-- [RP2] [FP3] --C4-- [IF5]
        [IF2]                                              [IF6]
        [IF3] --C2-- [FP2]                    [FP4] --C5-- [IF7]
        [IF4]                                              [IF8]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
            Interface.objects.create(device=self.device, name='Interface 5'),
            Interface.objects.create(device=self.device, name='Interface 6'),
            Interface.objects.create(device=self.device, name='Interface 7'),
            Interface.objects.create(device=self.device, name='Interface 8'),
        ]
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1', positions=8)
        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2', positions=8)
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1:1', positions=4)
        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 1:2', positions=4)
        frontport3 = FrontPort.objects.create(device=self.device, name='Front Port 2:1', positions=4)
        frontport4 = FrontPort.objects.create(device=self.device, name='Front Port 2:2', positions=4)
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=1,
                rear_port=rearport1,
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=2,
                rear_port=rearport1,
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport2,
                front_port_position=1,
                rear_port=rearport1,
                rear_port_position=5,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport2,
                front_port_position=2,
                rear_port=rearport1,
                rear_port_position=6,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport3,
                front_port_position=1,
                rear_port=rearport2,
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport3,
                front_port_position=2,
                rear_port=rearport2,
                rear_port_position=2,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport4,
                front_port_position=1,
                rear_port=rearport2,
                rear_port_position=5,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport4,
                front_port_position=2,
                rear_port=rearport2,
                rear_port_position=6,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[frontport1],
            b_terminations=[interfaces[0], interfaces[1]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[frontport2],
            b_terminations=[interfaces[2], interfaces[3]],
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            profile=CableProfileChoices.SINGLE_1C8P,
            a_terminations=[rearport1],
            b_terminations=[rearport2]
        )
        cable3.clean()
        cable3.save()
        cable4 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[frontport3],
            b_terminations=[interfaces[4], interfaces[5]],
        )
        cable4.clean()
        cable4.save()
        cable5 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[frontport4],
            b_terminations=[interfaces[6], interfaces[7]],
        )
        cable5.clean()
        cable5.save()

        paths = [
            self.assertPathExists(
                (
                    interfaces[0], cable1, frontport1, rearport1, cable3, rearport2, frontport3, cable4,
                    interfaces[4],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[1], cable1, frontport1, rearport1, cable3, rearport2, frontport3, cable4,
                    interfaces[5],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[2], cable2, frontport2, rearport1, cable3, rearport2, frontport4, cable5,
                    interfaces[6],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[3], cable2, frontport2, rearport1, cable3, rearport2, frontport4, cable5,
                    interfaces[7],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[4], cable4, frontport3, rearport2, cable3, rearport1, frontport1, cable1,
                    interfaces[0],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[5], cable4, frontport3, rearport2, cable3, rearport1, frontport1, cable1,
                    interfaces[1],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[6], cable5, frontport4, rearport2, cable3, rearport1, frontport2, cable2,
                    interfaces[2],
                ),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (
                    interfaces[7], cable5, frontport4, rearport2, cable3, rearport1, frontport2, cable2,
                    interfaces[3],
                ),
                is_complete=True,
                is_active=True,
            ),
        ]
        self.assertEqual(CablePath.objects.count(), 8)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], paths[0])
        self.assertPathIsSet(interfaces[1], paths[1])
        self.assertPathIsSet(interfaces[2], paths[2])
        self.assertPathIsSet(interfaces[3], paths[3])
        self.assertPathIsSet(interfaces[4], paths[4])
        self.assertPathIsSet(interfaces[5], paths[5])
        self.assertPathIsSet(interfaces[6], paths[6])
        self.assertPathIsSet(interfaces[7], paths[7])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_212_interface_to_interface_via_circuit_with_breakouts(self):
        """
        [IF1] --C1-- [CT1] [CT2] --C2-- [IF3]
        [IF2]                           [IF4]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination2 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='Z'
        )

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[circuittermination1],
            b_terminations=[interfaces[0], interfaces[1]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C4P_4C1P,
            a_terminations=[circuittermination2],
            b_terminations=[interfaces[2], interfaces[3]]
        )
        cable2.clean()
        cable2.save()

        # Check for two complete paths in either direction
        paths = [
            self.assertPathExists(
                (interfaces[0], cable1, circuittermination1, circuittermination2, cable2, interfaces[2]),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (interfaces[1], cable1, circuittermination1, circuittermination2, cable2, interfaces[3]),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (interfaces[2], cable2, circuittermination2, circuittermination1, cable1, interfaces[0]),
                is_complete=True,
                is_active=True,
            ),
            self.assertPathExists(
                (interfaces[3], cable2, circuittermination2, circuittermination1, cable1, interfaces[1]),
                is_complete=True,
                is_active=True,
            ),
        ]
        self.assertEqual(CablePath.objects.count(), 4)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], paths[0])
        self.assertPathIsSet(interfaces[1], paths[1])
        self.assertPathIsSet(interfaces[2], paths[2])
        self.assertPathIsSet(interfaces[3], paths[3])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    # TBD: Is this a topology we want to support?
    @skip("Test applicability TBD")
    def test_217_interface_to_interface_via_rear_ports(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C2-- [RP3] [FP3] --C3-- [IF2]
                     [FP2] [RP2]        [RP4] [FP4]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1'),
            RearPort.objects.create(device=self.device, name='Rear Port 2'),
            RearPort.objects.create(device=self.device, name='Rear Port 3'),
            RearPort.objects.create(device=self.device, name='Rear Port 4'),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
            FrontPort.objects.create(device=self.device, name='Front Port 3'),
            FrontPort.objects.create(device=self.device, name='Front Port 4'),
        ]
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=front_ports[0],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[1],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[2],
                front_port_position=1,
                rear_port=rear_ports[2],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[3],
                front_port_position=1,
                rear_port=rear_ports[3],
                rear_port_position=1,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_2C1P,
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0], front_ports[1]]
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            a_terminations=[rear_ports[0], rear_ports[1]],
            b_terminations=[rear_ports[2], rear_ports[3]]
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            profile=CableProfileChoices.SINGLE_2C1P,
            a_terminations=[interfaces[1]],
            b_terminations=[front_ports[2], front_ports[3]]
        )
        cable3.clean()
        cable3.save()

        # Check for one complete path in either direction
        paths = [
            self.assertPathExists(
                (
                    interfaces[0], cable1, (front_ports[0], front_ports[1]), (rear_ports[0], rear_ports[1]), cable2,
                    (rear_ports[2], rear_ports[3]), (front_ports[2], front_ports[3]), cable3, interfaces[1]
                ),
                is_complete=True
            ),
            self.assertPathExists(
                (
                    interfaces[1], cable3, (front_ports[2], front_ports[3]), (rear_ports[2], rear_ports[3]), cable2,
                    (rear_ports[0], rear_ports[1]), (front_ports[0], front_ports[1]), cable1, interfaces[0]
                ),
                is_complete=True
            ),
        ]
        self.assertEqual(CablePath.objects.count(), 2)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], paths[0])
        self.assertPathIsSet(interfaces[1], paths[1])

        # Test SVG generation
        CableTraceSVG(interfaces[0]).render()

    def test_223_single_path_via_multiple_pass_throughs_with_breakouts(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C2-- [IF3]
        [IF2]        [FP2] [RP2]        [IF4]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=frontport1,
                front_port_position=1,
                rear_port=rearport1,
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=frontport2,
                front_port_position=1,
                rear_port=rearport2,
                rear_port_position=1,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.TRUNK_2C2P,
            a_terminations=[interfaces[0], interfaces[1]],
            b_terminations=[frontport1, frontport2]
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.TRUNK_2C2P,
            a_terminations=[rearport1, rearport2],
            b_terminations=[interfaces[2], interfaces[3]]
        )
        cable2.clean()
        cable2.save()

        # Validate paths
        self.assertPathExists(
            (interfaces[0], cable1, frontport1, rearport1, cable2, interfaces[2]),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interfaces[1], cable1, frontport2, rearport2, cable2, interfaces[3]),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interfaces[2], cable2, rearport1, frontport1, cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interfaces[3], cable2, rearport2, frontport2, cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 4)

    def test_225_breakout_1c2p_2c1p_to_single_position_passthroughs(self):
        """
        Regression test for #22187: a 1C2P:2C1P breakout cable terminating on two
        single-position FrontPorts (each mapping 1:1 to a single-position RearPort)
        which are then connected to PathEndpoints via unprofiled cables.

        [IF1] --C1 (1C2P:2C1P)-- [FP1] [RP1] --C2 (unprofiled)-- [IF2]
                                 [FP2] [RP2] --C3 (unprofiled)-- [IF3]
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1'),
            RearPort.objects.create(device=self.device, name='Rear Port 2'),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
        ]
        PortMapping.objects.bulk_create([
            PortMapping(
                device=self.device,
                front_port=front_ports[0],
                front_port_position=1,
                rear_port=rear_ports[0],
                rear_port_position=1,
            ),
            PortMapping(
                device=self.device,
                front_port=front_ports[1],
                front_port_position=1,
                rear_port=rear_ports[1],
                rear_port_position=1,
            ),
        ])

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.BREAKOUT_1C2P_2C1P,
            a_terminations=[interfaces[0]],
            b_terminations=[front_ports[0], front_ports[1]],
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            a_terminations=[rear_ports[0]],
            b_terminations=[interfaces[1]],
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            a_terminations=[rear_ports[1]],
            b_terminations=[interfaces[2]],
        )
        cable3.clean()
        cable3.save()

        # The breakout splits IF1's two positions into separate downstream cables,
        # so the forward path has FP1/FP2, RP1/RP2, and the two unprofiled cables
        # at the corresponding hops.
        path1 = self.assertPathExists(
            (
                interfaces[0],
                cable1,
                [front_ports[0], front_ports[1]],
                [rear_ports[0], rear_ports[1]],
                [cable2, cable3],
                [interfaces[1], interfaces[2]],
            ),
            is_complete=True,
            is_active=True,
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable2, rear_ports[0], front_ports[0], cable1, interfaces[0]),
            is_complete=True,
            is_active=True,
        )
        path3 = self.assertPathExists(
            (interfaces[2], cable3, rear_ports[1], front_ports[1], cable1, interfaces[0]),
            is_complete=True,
            is_active=True,
        )
        self.assertEqual(CablePath.objects.count(), 3)
        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)

        # Test SVG generation from both directions
        CableTraceSVG(interfaces[0]).render()
        CableTraceSVG(interfaces[1]).render()
        CableTraceSVG(interfaces[2]).render()

    def test_226_total_length_via_circuit(self):
        """
        [IF1] --C1-- [CT1] [CT2] --C2-- [IF2]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination2 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='Z'
        )

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1]
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[circuittermination2],
            b_terminations=[interface2]
        )
        cable2.clean()
        cable2.save()

        # Check for complete paths in both directions
        paths = [
            self.assertPathExists(
                (interface1, cable1, circuittermination1, circuittermination2, cable2, interface2),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (interface2, cable2, circuittermination2, circuittermination1, cable1, interface1),
                is_complete=True,
                is_active=True
            ),
        ]

        # The crossed circuit's distance counts toward the total path length
        for path in paths:
            self.assertEqual(path.get_total_length(), (10400, True))

        # An unset circuit distance makes the total length non-definitive
        self.circuit.distance = None
        self.circuit.save()
        for path in paths:
            self.assertEqual(path.get_total_length(), (400, False))

        # A circuit distance of zero is a known value and remains definitive
        self.circuit.distance = 0
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()
        for path in paths:
            self.assertEqual(path.get_total_length(), (400, True))

    def test_227_total_length_via_circuit_without_peer_termination(self):
        """
        [IF1] --C1-- [CT1]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1]
        )
        cable1.clean()
        cable1.save()

        # The distance of a circuit which the path does not cross is excluded
        path = self.assertPathExists(
            (interface1, cable1, circuittermination1),
            is_complete=False
        )
        self.assertEqual(path.get_total_length(), (200, True))

    def test_228_total_length_via_multiple_circuits(self):
        """
        [IF1] --C1-- [CT1] [CT2] --C2-- [CT3] [CT4] --C3-- [IF2]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()
        circuit2 = Circuit.objects.create(
            provider=self.circuit.provider,
            type=self.circuit.type,
            cid='Circuit 2',
            distance=5,
            distance_unit=DistanceUnitChoices.UNIT_KILOMETER
        )

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination2 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='Z'
        )
        circuittermination3 = CircuitTermination.objects.create(
            circuit=circuit2,
            termination=self.site,
            term_side='A'
        )
        circuittermination4 = CircuitTermination.objects.create(
            circuit=circuit2,
            termination=self.site,
            term_side='Z'
        )

        # Create cables
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1]
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=100,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[circuittermination2],
            b_terminations=[circuittermination3]
        )
        cable2.clean()
        cable2.save()
        cable3 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[circuittermination4],
            b_terminations=[interface2]
        )
        cable3.clean()
        cable3.save()

        # Check for complete paths in both directions
        paths = [
            self.assertPathExists(
                (
                    interface1, cable1, circuittermination1, circuittermination2, cable2, circuittermination3,
                    circuittermination4, cable3, interface2,
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interface2, cable3, circuittermination4, circuittermination3, cable2, circuittermination2,
                    circuittermination1, cable1, interface1,
                ),
                is_complete=True,
                is_active=True
            ),
        ]

        # Each crossed circuit adds its distance to the total path length
        for path in paths:
            self.assertEqual(path.get_total_length(), (15500, True))

    def test_229_total_length_via_circuit_to_site(self):
        """
        [IF1] --C1-- [CT1] [CT2] --> [Site2]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        site2 = Site.objects.create(name='Site 2', slug='site-2')
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination2 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=site2,
            term_side='Z'
        )
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1]
        )
        cable1.clean()
        cable1.save()

        # The distance of a circuit crossed to reach its far-side site counts toward the total length
        path = self.assertPathExists(
            (interface1, cable1, circuittermination1, circuittermination2, site2),
            is_active=True
        )
        self.assertEqual(path.get_total_length(), (10200, True))

    def test_230_total_length_via_circuit_to_providernetwork(self):
        """
        [IF1] --C1-- [CT1] [CT2] --> [PN1]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        providernetwork = ProviderNetwork.objects.create(name='Provider Network 1', provider=self.circuit.provider)
        circuittermination1 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination2 = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=providernetwork,
            term_side='Z'
        )
        cable1 = Cable(
            profile=CableProfileChoices.SINGLE_1C1P,
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1]
        )
        cable1.clean()
        cable1.save()

        # The distance of a circuit crossed to reach a provider network counts toward the total length
        path = self.assertPathExists(
            (interface1, cable1, circuittermination1, circuittermination2, providernetwork),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(path.get_total_length(), (10200, True))

    def test_231_total_length_via_parallel_circuits(self):
        """
        [IF1] --C1-- [CT1_A] [CT1_Z] --C2-- [IF2]
                     [CT2_A] [CT2_Z]
        """
        self.circuit.distance = 10
        self.circuit.distance_unit = DistanceUnitChoices.UNIT_KILOMETER
        self.circuit.save()
        circuit2 = Circuit.objects.create(
            provider=self.circuit.provider,
            type=self.circuit.type,
            cid='Circuit 2',
            distance=5,
            distance_unit=DistanceUnitChoices.UNIT_KILOMETER
        )

        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        circuittermination1_A = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='A'
        )
        circuittermination1_Z = CircuitTermination.objects.create(
            circuit=self.circuit,
            termination=self.site,
            term_side='Z'
        )
        circuittermination2_A = CircuitTermination.objects.create(
            circuit=circuit2,
            termination=self.site,
            term_side='A'
        )
        circuittermination2_Z = CircuitTermination.objects.create(
            circuit=circuit2,
            termination=self.site,
            term_side='Z'
        )

        # Create cables
        cable1 = Cable(
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[interface1],
            b_terminations=[circuittermination1_A, circuittermination2_A]
        )
        cable1.clean()
        cable1.save()
        cable2 = Cable(
            length=200,
            length_unit=CableLengthUnitChoices.UNIT_METER,
            a_terminations=[circuittermination1_Z, circuittermination2_Z],
            b_terminations=[interface2]
        )
        cable2.clean()
        cable2.save()

        # Check for complete paths in both directions
        paths = [
            self.assertPathExists(
                (
                    interface1, cable1, (circuittermination1_A, circuittermination2_A),
                    (circuittermination1_Z, circuittermination2_Z), cable2, interface2,
                ),
                is_complete=True,
                is_active=True
            ),
            self.assertPathExists(
                (
                    interface2, cable2, (circuittermination1_Z, circuittermination2_Z),
                    (circuittermination1_A, circuittermination2_A), cable1, interface1,
                ),
                is_complete=True,
                is_active=True
            ),
        ]

        # Parallel circuits crossed in the same hop count only the longest distance
        for path in paths:
            self.assertEqual(path.get_total_length(), (10400, True))

        # An unset distance on one parallel circuit keeps the longest known distance but is non-definitive
        circuit2.distance = None
        circuit2.save()
        for path in paths:
            self.assertEqual(path.get_total_length(), (10400, False))

    def test_304_add_port_mapping_between_connected_ports(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C2-- [IF2]
        """
        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
        cable1 = Cable(
            a_terminations=[interface1],
            b_terminations=[frontport1]
        )
        cable1.save()
        cable2 = Cable(
            a_terminations=[interface2],
            b_terminations=[rearport1]
        )
        cable2.save()

        # Check for incomplete paths
        self.assertPathExists(
            (interface1, cable1, frontport1),
            is_complete=False,
            is_active=True
        )
        self.assertPathExists(
            (interface2, cable2, rearport1),
            is_complete=False,
            is_active=True
        )

        # Create a PortMapping between frontport1 and rearport1
        PortMapping.objects.create(
            device=self.device,
            front_port=frontport1,
            front_port_position=1,
            rear_port=rearport1,
            rear_port_position=1,
        )

        # Check that paths are now complete
        self.assertPathExists(
            (interface1, cable1, frontport1, rearport1, cable2, interface2),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interface2, cable2, rearport1, frontport1, cable1, interface1),
            is_complete=True,
            is_active=True
        )

    def test_305_delete_port_mapping_between_connected_ports(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C2-- [IF2]
        """
        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
        cable1 = Cable(
            a_terminations=[interface1],
            b_terminations=[frontport1]
        )
        cable1.save()
        cable2 = Cable(
            a_terminations=[interface2],
            b_terminations=[rearport1]
        )
        cable2.save()
        portmapping1 = PortMapping.objects.create(
            device=self.device,
            front_port=frontport1,
            front_port_position=1,
            rear_port=rearport1,
            rear_port_position=1,
        )

        # Check for complete paths
        self.assertPathExists(
            (interface1, cable1, frontport1, rearport1, cable2, interface2),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interface2, cable2, rearport1, frontport1, cable1, interface1),
            is_complete=True,
            is_active=True
        )

        # Delete the PortMapping between frontport1 and rearport1
        portmapping1.delete()

        # Check that paths are no longer complete
        self.assertPathExists(
            (interface1, cable1, frontport1),
            is_complete=False,
            is_active=True
        )
        self.assertPathExists(
            (interface2, cable2, rearport1),
            is_complete=False,
            is_active=True
        )

    def test_306_change_port_mapping_between_connected_ports(self):
        """
        [IF1] --C1-- [FP1] [RP1] --C3-- [IF3]
        [IF2] --C2-- [FP2] [RP3] --C4-- [IF4]
        """
        interface1 = Interface.objects.create(device=self.device, name='Interface 1')
        interface2 = Interface.objects.create(device=self.device, name='Interface 2')
        interface3 = Interface.objects.create(device=self.device, name='Interface 3')
        interface4 = Interface.objects.create(device=self.device, name='Interface 4')
        frontport1 = FrontPort.objects.create(device=self.device, name='Front Port 1')
        frontport2 = FrontPort.objects.create(device=self.device, name='Front Port 2')
        rearport1 = RearPort.objects.create(device=self.device, name='Rear Port 1')
        rearport2 = RearPort.objects.create(device=self.device, name='Rear Port 2')
        cable1 = Cable(
            a_terminations=[interface1],
            b_terminations=[frontport1]
        )
        cable1.save()
        cable2 = Cable(
            a_terminations=[interface2],
            b_terminations=[frontport2]
        )
        cable2.save()
        cable3 = Cable(
            a_terminations=[interface3],
            b_terminations=[rearport1]
        )
        cable3.save()
        cable4 = Cable(
            a_terminations=[interface4],
            b_terminations=[rearport2]
        )
        cable4.save()
        portmapping1 = PortMapping.objects.create(
            device=self.device,
            front_port=frontport1,
            front_port_position=1,
            rear_port=rearport1,
            rear_port_position=1,
        )

        # Verify expected initial paths
        self.assertPathExists(
            (interface1, cable1, frontport1, rearport1, cable3, interface3),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interface3, cable3, rearport1, frontport1, cable1, interface1),
            is_complete=True,
            is_active=True
        )

        # Delete and replace the PortMapping to connect interface1 to interface4
        portmapping1.delete()
        portmapping2 = PortMapping.objects.create(
            device=self.device,
            front_port=frontport1,
            front_port_position=1,
            rear_port=rearport2,
            rear_port_position=1,
        )

        # Verify expected new paths
        self.assertPathExists(
            (interface1, cable1, frontport1, rearport2, cable4, interface4),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interface4, cable4, rearport2, frontport1, cable1, interface1),
            is_complete=True,
            is_active=True
        )

        # Delete and replace the PortMapping to connect interface2 to interface4
        portmapping2.delete()
        PortMapping.objects.create(
            device=self.device,
            front_port=frontport2,
            front_port_position=1,
            rear_port=rearport2,
            rear_port_position=1,
        )

        # Verify expected new paths
        self.assertPathExists(
            (interface2, cable2, frontport2, rearport2, cable4, interface4),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interface4, cable4, rearport2, frontport2, cable2, interface2),
            is_complete=True,
            is_active=True
        )

    def test_307_change_cable_profile_rebuilds_paths(self):
        """
        [IF1] --C1-- [IF2]

        Applying a profile to an existing cable rebuilds its paths.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]

        # Create cable 1 without a profile
        cable1 = Cable(
            a_terminations=[interfaces[0]],
            b_terminations=[interfaces[1]],
        )
        cable1.clean()
        cable1.save()

        self.assertPathExists(
            (interfaces[0], cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            (interfaces[1], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )

        # Reload so _terminations_modified starts False, as it does in a bulk edit
        cable1 = Cable.objects.get(pk=cable1.pk)
        cable1.profile = CableProfileChoices.SINGLE_1C1P
        cable1.full_clean()
        cable1.save()

        path1 = self.assertPathExists(
            (interfaces[0], cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)
        interfaces[0].refresh_from_db()
        interfaces[1].refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)

    def test_308_change_cable_profile_regroups_trunk_paths(self):
        """
        [IF1] --C1-- [IF3]
        [IF2]        [IF4]

        Applying a trunk profile to an existing cable regroups its paths by connector, and
        clearing it again collapses them.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
            Interface.objects.create(device=self.device, name='Interface 3'),
            Interface.objects.create(device=self.device, name='Interface 4'),
        ]

        # Create cable 1 without a profile
        cable1 = Cable(
            a_terminations=[interfaces[0], interfaces[1]],
            b_terminations=[interfaces[2], interfaces[3]],
        )
        cable1.clean()
        cable1.save()

        # Without a profile both terminations on each end share a single path
        self.assertPathExists(
            ((interfaces[0], interfaces[1]), cable1, (interfaces[2], interfaces[3])),
            is_complete=True,
            is_active=True
        )
        self.assertPathExists(
            ((interfaces[2], interfaces[3]), cable1, (interfaces[0], interfaces[1])),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)

        # Reload so _terminations_modified starts False, as it does in a bulk edit
        cable1 = Cable.objects.get(pk=cable1.pk)
        cable1.profile = CableProfileChoices.TRUNK_2C1P
        cable1.full_clean()
        cable1.save()

        path1 = self.assertPathExists(
            (interfaces[0], cable1, interfaces[2]),
            is_complete=True,
            is_active=True
        )
        path2 = self.assertPathExists(
            (interfaces[1], cable1, interfaces[3]),
            is_complete=True,
            is_active=True
        )
        path3 = self.assertPathExists(
            (interfaces[2], cable1, interfaces[0]),
            is_complete=True,
            is_active=True
        )
        path4 = self.assertPathExists(
            (interfaces[3], cable1, interfaces[1]),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 4)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)
        self.assertPathIsSet(interfaces[2], path3)
        self.assertPathIsSet(interfaces[3], path4)
        self.assertEqual(interfaces[0].cable_connector, 1)
        self.assertEqual(interfaces[1].cable_connector, 2)
        self.assertEqual(interfaces[2].cable_connector, 1)
        self.assertEqual(interfaces[3].cable_connector, 2)
        for interface in interfaces:
            self.assertEqual(interface.cable_positions, [1])

        # Clearing the profile is a bulk-edit action in its own right
        cable1 = Cable.objects.get(pk=cable1.pk)
        cable1.profile = ''
        cable1.full_clean()
        cable1.save()

        path5 = self.assertPathExists(
            ((interfaces[0], interfaces[1]), cable1, (interfaces[2], interfaces[3])),
            is_complete=True,
            is_active=True
        )
        path6 = self.assertPathExists(
            ((interfaces[2], interfaces[3]), cable1, (interfaces[0], interfaces[1])),
            is_complete=True,
            is_active=True
        )
        self.assertEqual(CablePath.objects.count(), 2)

        for interface in interfaces:
            interface.refresh_from_db()
            self.assertIsNone(interface.cable_connector)
        self.assertPathIsSet(interfaces[0], path5)
        self.assertPathIsSet(interfaces[1], path5)
        self.assertPathIsSet(interfaces[2], path6)
        self.assertPathIsSet(interfaces[3], path6)

    def test_309_change_midspan_cable_profile_rebuilds_paths(self):
        """
        [IF1] --C1-- [FP1][RP1] --C3-- [RP2][FP2] --C2-- [IF2]

        Applying a profile to a cable which terminates on pass-through ports rebuilds the
        paths traversing it. The rear ports are not path origins, so a missing rebuild
        truncates those paths rather than deleting them.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name='Rear Port 1'),
            RearPort.objects.create(device=self.device, name='Rear Port 2'),
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name='Front Port 1'),
            FrontPort.objects.create(device=self.device, name='Front Port 2'),
        ]
        for front_port, rear_port in zip(front_ports, rear_ports):
            PortMapping.objects.create(
                device=self.device,
                front_port=front_port,
                front_port_position=1,
                rear_port=rear_port,
                rear_port_position=1
            )

        cable1 = Cable(a_terminations=[interfaces[0]], b_terminations=[front_ports[0]])
        cable1.clean()
        cable1.save()
        cable2 = Cable(a_terminations=[front_ports[1]], b_terminations=[interfaces[1]])
        cable2.clean()
        cable2.save()

        # Create the mid-span cable without a profile
        cable3 = Cable(a_terminations=[rear_ports[0]], b_terminations=[rear_ports[1]])
        cable3.clean()
        cable3.save()

        nodes_a_to_b = (
            interfaces[0], cable1, front_ports[0], rear_ports[0], cable3, rear_ports[1], front_ports[1], cable2,
            interfaces[1],
        )
        nodes_b_to_a = (
            interfaces[1], cable2, front_ports[1], rear_ports[1], cable3, rear_ports[0], front_ports[0], cable1,
            interfaces[0],
        )
        self.assertPathExists(nodes_a_to_b, is_complete=True, is_active=True)
        self.assertPathExists(nodes_b_to_a, is_complete=True, is_active=True)
        self.assertEqual(CablePath.objects.count(), 2)

        # Reload so _terminations_modified starts False, as it does in a bulk edit
        cable3 = Cable.objects.get(pk=cable3.pk)
        cable3.profile = CableProfileChoices.SINGLE_1C1P
        cable3.full_clean()
        cable3.save()

        path1 = self.assertPathExists(nodes_a_to_b, is_complete=True, is_active=True)
        path2 = self.assertPathExists(nodes_b_to_a, is_complete=True, is_active=True)
        self.assertEqual(CablePath.objects.count(), 2)

        for interface in interfaces:
            interface.refresh_from_db()
        self.assertPathIsSet(interfaces[0], path1)
        self.assertPathIsSet(interfaces[1], path2)

    def test_310_repeat_save_does_not_recreate_paths(self):
        """
        [IF1] --C1-- [IF2]

        Saving an unchanged cable again leaves its terminations and paths untouched.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name='Interface 1'),
            Interface.objects.create(device=self.device, name='Interface 2'),
        ]

        cable1 = Cable(
            a_terminations=[interfaces[0]],
            b_terminations=[interfaces[1]],
        )
        cable1.clean()
        cable1.save()

        path_pks = set(CablePath.objects.values_list('pk', flat=True))
        termination_pks = set(CableTermination.objects.filter(cable=cable1).values_list('pk', flat=True))
        self.assertEqual(len(path_pks), 2)
        self.assertEqual(len(termination_pks), 2)

        # Saving the same instance again must not duplicate its paths
        cable1.save()
        self.assertEqual(set(CablePath.objects.values_list('pk', flat=True)), path_pks)
        self.assertEqual(
            set(CableTermination.objects.filter(cable=cable1).values_list('pk', flat=True)),
            termination_pks
        )

        # Reload so _terminations_modified starts False, as it does in a bulk edit
        cable1 = Cable.objects.get(pk=cable1.pk)
        cable1.profile = CableProfileChoices.SINGLE_1C1P
        cable1.full_clean()
        cable1.save()

        path_pks = set(CablePath.objects.values_list('pk', flat=True))
        termination_pks = set(CableTermination.objects.filter(cable=cable1).values_list('pk', flat=True))
        self.assertEqual(len(path_pks), 2)
        self.assertEqual(len(termination_pks), 2)

        # The profile change is applied once, so a second save must not recreate anything
        cable1.save()
        self.assertEqual(set(CablePath.objects.values_list('pk', flat=True)), path_pks)
        self.assertEqual(
            set(CableTermination.objects.filter(cable=cable1).values_list('pk', flat=True)),
            termination_pks
        )

    def test_311_moving_a_midspan_termination_preserves_far_end_paths(self):
        """
        [IF1] --C1-- [FP1][RP1] --C3-- [RP2][FP2] --C2-- [IF2]
        becomes
        [IF1] --C1-- [FP1][RP1] --C3-- [RP3][FP3] --C4-- [IF3]

        Rear ports originate no path, so moving a mid-span cable's end must retrace the rows which traverse it
        rather than delete them: their origins cannot be recovered from the cable's own terminations.
        """
        interfaces = [
            Interface.objects.create(device=self.device, name=f'Interface {i}') for i in range(1, 4)
        ]
        rear_ports = [
            RearPort.objects.create(device=self.device, name=f'Rear Port {i}') for i in range(1, 4)
        ]
        front_ports = [
            FrontPort.objects.create(device=self.device, name=f'Front Port {i}') for i in range(1, 4)
        ]
        for front_port, rear_port in zip(front_ports, rear_ports):
            PortMapping.objects.create(
                device=self.device,
                front_port=front_port,
                front_port_position=1,
                rear_port=rear_port,
                rear_port_position=1
            )

        cable1 = Cable(a_terminations=[interfaces[0]], b_terminations=[front_ports[0]])
        cable1.clean()
        cable1.save()
        cable2 = Cable(a_terminations=[front_ports[1]], b_terminations=[interfaces[1]])
        cable2.clean()
        cable2.save()
        cable3 = Cable(a_terminations=[rear_ports[0]], b_terminations=[rear_ports[1]])
        cable3.clean()
        cable3.save()
        cable4 = Cable(a_terminations=[front_ports[2]], b_terminations=[interfaces[2]])
        cable4.clean()
        cable4.save()

        before = (
            interfaces[0], cable1, front_ports[0], rear_ports[0], cable3, rear_ports[1], front_ports[1], cable2,
            interfaces[1],
        )
        self.assertCurrentPathExists(before, is_complete=True, is_active=True)
        self.assertCurrentPathExists(tuple(reversed(before)), is_complete=True, is_active=True)
        # Two for the completed link, one for the third interface stopping at its own rear port
        self.assertEqual(CablePath.objects.count(), 3)

        cable3 = Cable.objects.get(pk=cable3.pk)
        cable3.b_terminations = [rear_ports[2]]
        cable3.full_clean()
        cable3.save()

        after = (
            interfaces[0], cable1, front_ports[0], rear_ports[0], cable3, rear_ports[2], front_ports[2], cable4,
            interfaces[2],
        )
        self.assertCurrentPathExists(after, is_complete=True, is_active=True)
        self.assertCurrentPathExists(tuple(reversed(after)), is_complete=True, is_active=True)
        self.assertCurrentPathExists(
            (interfaces[1], cable2, front_ports[1], rear_ports[1]), is_complete=False
        )
        self.assertEqual(CablePath.objects.count(), 3)