package config

import (
	"os"
	"testing"

	"github.com/knadh/koanf/parsers/yaml"
	"github.com/knadh/koanf/providers/rawbytes"
	"github.com/knadh/koanf/v2"
	"github.com/stretchr/testify/assert"
)

var stringEnvConfigYaml = `
PageTitle: ${{ INPUT }}
`

var stringEnvInterpolationConfigYaml = `
PageTitle: Olivetin - ${{ INPUT }}
`

var boolEnvConfigYaml = `
CheckForUpdates: ${{ INPUT }}
`

var numericEnvConfigYaml = `
LogHistoryPageSize: ${{ INPUT }}
`

var argsSyntaxConfigYaml = `
actions:
  - title: Ping host
    id: ping_host
    shell: ping {{ host }} -c ${{ INPUT }}
    icon: ping
    timeout: 100
    popupOnStart: execution-dialog-stdout-only
    arguments:
      - name: host
        title: Host
        type: ascii_identifier
        default: example.com
        description: The host that you want to ping
`

func pageTitleSelector(cfg *Config) any {
	return cfg.PageTitle
}

func checkForUpdatesSelector(cfg *Config) any {
	return cfg.CheckForUpdates
}

func logHistoryPageSizeSelector(cfg *Config) any {
	return cfg.LogHistoryPageSize
}

var envConfigTests = []struct {
	yaml     string
	input    string
	output   any
	selector func(*Config) any
}{
	// Test that it works for string type config fields, both standalone and as part of a larger string value.
	{stringEnvConfigYaml, "A Nice Title", "A Nice Title", pageTitleSelector},
	{stringEnvInterpolationConfigYaml, "A Nice Title", "Olivetin - A Nice Title", pageTitleSelector},
	// Test that unset variables turn into empty strings.
	{stringEnvConfigYaml, "", "", pageTitleSelector},
	// Test that it works for bool type config fields for intuitive bool->string conversions.
	{boolEnvConfigYaml, "FALSE", false, checkForUpdatesSelector},
	{boolEnvConfigYaml, "false", false, checkForUpdatesSelector},
	{boolEnvConfigYaml, "False", false, checkForUpdatesSelector},
	{boolEnvConfigYaml, "TRUE", true, checkForUpdatesSelector},
	{boolEnvConfigYaml, "true", true, checkForUpdatesSelector},
	{boolEnvConfigYaml, "True", true, checkForUpdatesSelector},
	{boolEnvConfigYaml, "0", false, checkForUpdatesSelector},
	{boolEnvConfigYaml, "1", true, checkForUpdatesSelector},
	// Test that unset variables turn into false bools.
	{boolEnvConfigYaml, "", false, checkForUpdatesSelector},
	// Test that it works for numeric type config fields.
	{numericEnvConfigYaml, "2048", int64(2048), logHistoryPageSizeSelector},
	// Test that unset variables turn into zero numbers.
	{numericEnvConfigYaml, "", int64(0), logHistoryPageSizeSelector},
	// Test that it doesn't interfere with similar arguments
	{argsSyntaxConfigYaml, "5", "ping {{ host }} -c 5", func(cfg *Config) any {
		if len(cfg.Actions) > 0 {
			return cfg.Actions[0].Shell
		}
		return ""
	}},
}

func setTestEnvInput(t *testing.T, input string) {
	t.Helper()
	if input != "" {
		if err := os.Setenv("INPUT", input); err != nil {
			t.Fatalf("Setenv INPUT: %v", err)
		}
		return
	}
	if err := os.Unsetenv("INPUT"); err != nil {
		t.Fatalf("Unsetenv INPUT: %v", err)
	}
}

func loadConfigFromYAML(t *testing.T, yamlStr string, cfg *Config) bool {
	t.Helper()
	k := koanf.New(".")
	if err := k.Load(rawbytes.Provider([]byte(yamlStr)), yaml.Parser()); err != nil {
		t.Errorf("Error loading YAML: %v", err)
		return false
	}
	return unmarshalRoot(k, cfg)
}

func TestEnvInConfig(t *testing.T) {
	originalInput, hadInput := os.LookupEnv("INPUT")
	t.Cleanup(func() {
		if hadInput {
			setTestEnvInput(t, originalInput)
			return
		}
		setTestEnvInput(t, "")
	})

	for _, tt := range envConfigTests {
		cfg := DefaultConfig()
		setTestEnvInput(t, tt.input)
		if !loadConfigFromYAML(t, tt.yaml, cfg) {
			t.Errorf("Error unmarshalling config for env=%q", tt.input)
			continue
		}
		field := tt.selector(cfg)
		assert.Equal(t, tt.output, field,
			"Unmarshaled config field doesn't match expected value: env=%q", tt.input)
	}
}