from __future__ import annotations

from pathlib import Path
import logging
from typing import Optional
import yaml

from .exceptions import LibraryError, TemplateNotFoundError, DuplicateTemplateError

logger = logging.getLogger(__name__)


class Library:
    """Represents a single library with a specific path."""

    def __init__(
        self, name: str, path: Path, priority: int = 0, library_type: str = "git"
    ) -> None:
        """Initialize a library instance.

        Args:
          name: Display name for the library
          path: Path to the library directory
          priority: Priority for library lookup (higher = checked first)
          library_type: Type of library ("git" or "static")
        """
        if library_type not in ("git", "static"):
            raise ValueError(
                f"Invalid library type: {library_type}. Must be 'git' or 'static'."
            )

        self.name = name
        self.path = path
        self.priority = priority  # Higher priority = checked first
        self.library_type = library_type

    def _is_template_draft(self, template_path: Path) -> bool:
        """Check if a template is marked as draft."""
        # Find the template file
        for filename in ("template.yaml", "template.yml"):
            template_file = template_path / filename
            if template_file.exists():
                break
        else:
            return False

        try:
            with open(template_file, "r", encoding="utf-8") as f:
                docs = [doc for doc in yaml.safe_load_all(f) if doc]
                return (
                    docs[0].get("metadata", {}).get("draft", False) if docs else False
                )
        except (yaml.YAMLError, IOError, OSError) as e:
            logger.warning(f"Error checking draft status for {template_path}: {e}")
            return False

    def find_by_id(self, module_name: str, template_id: str) -> tuple[Path, str]:
        """Find a template by its ID in this library.

        Args:
            module_name: The module name (e.g., 'compose', 'terraform')
            template_id: The template ID to find

        Returns:
            Path to the template directory if found

        Raises:
            FileNotFoundError: If the template ID is not found in this library or is marked as draft
        """
        logger.debug(
            f"Looking for template '{template_id}' in module '{module_name}' in library '{self.name}'"
        )

        # Build the path to the specific template directory
        template_path = self.path / module_name / template_id

        # Check if template directory exists with a template file
        has_template = template_path.is_dir() and any(
            (template_path / f).exists() for f in ("template.yaml", "template.yml")
        )

        if not has_template or self._is_template_draft(template_path):
            raise TemplateNotFoundError(template_id, module_name)

        logger.debug(f"Found template '{template_id}' at: {template_path}")
        return template_path, self.name

    def find(
        self, module_name: str, sort_results: bool = False
    ) -> list[tuple[Path, str]]:
        """Find templates in this library for a specific module.

        Excludes templates marked as draft.

        Args:
            module_name: The module name (e.g., 'compose', 'terraform')
            sort_results: Whether to return results sorted alphabetically

        Returns:
            List of Path objects representing template directories (excluding drafts)

        Raises:
            FileNotFoundError: If the module directory is not found in this library
        """
        logger.debug(
            f"Looking for templates in module '{module_name}' in library '{self.name}'"
        )

        # Build the path to the module directory
        module_path = self.path / module_name

        # Check if the module directory exists
        if not module_path.is_dir():
            raise LibraryError(
                f"Module '{module_name}' not found in library '{self.name}'"
            )

        # Track seen IDs to detect duplicates within this library
        seen_ids = {}
        template_dirs = []
        try:
            for item in module_path.iterdir():
                has_template = item.is_dir() and any(
                    (item / f).exists() for f in ("template.yaml", "template.yml")
                )
                if has_template and not self._is_template_draft(item):
                    template_id = item.name

                    # Check for duplicate within same library
                    if template_id in seen_ids:
                        raise DuplicateTemplateError(template_id, self.name)

                    seen_ids[template_id] = True
                    template_dirs.append((item, self.name))
                elif has_template:
                    logger.debug(f"Skipping draft template: {item.name}")
        except PermissionError as e:
            raise LibraryError(
                f"Permission denied accessing module '{module_name}' in library '{self.name}': {e}"
            )

        # Sort if requested
        if sort_results:
            template_dirs.sort(key=lambda x: x[0].name.lower())

        logger.debug(f"Found {len(template_dirs)} templates in module '{module_name}'")
        return template_dirs


class LibraryManager:
    """Manages multiple libraries and provides methods to find templates."""

    def __init__(self) -> None:
        """Initialize LibraryManager with git-based libraries from config."""
        from .config import ConfigManager

        self.config = ConfigManager()
        self.libraries = self._load_libraries_from_config()

    def _load_libraries_from_config(self) -> list[Library]:
        """Load libraries from configuration.

        Returns:
            List of Library instances
        """
        libraries = []
        libraries_path = self.config.get_libraries_path()

        # Get library configurations from config
        library_configs = self.config.get_libraries()

        for i, lib_config in enumerate(library_configs):
            # Skip disabled libraries
            if not lib_config.get("enabled", True):
                logger.debug(f"Skipping disabled library: {lib_config.get('name')}")
                continue

            name = lib_config.get("name")
            lib_type = lib_config.get(
                "type", "git"
            )  # Default to "git" for backward compat

            # Handle library type-specific path resolution
            if lib_type == "git":
                # Existing git logic
                directory = lib_config.get("directory", ".")

                # Build path to library: ~/.config/boilerplates/libraries/{name}/{directory}/
                # For sparse-checkout, files remain in the specified directory
                library_base = libraries_path / name
                if directory and directory != ".":
                    library_path = library_base / directory
                else:
                    library_path = library_base

            elif lib_type == "static":
                # New static logic - use path directly
                path_str = lib_config.get("path")
                if not path_str:
                    logger.warning(f"Static library '{name}' has no path configured")
                    continue

                # Expand ~ and resolve relative paths
                library_path = Path(path_str).expanduser()
                if not library_path.is_absolute():
                    # Resolve relative to config directory
                    library_path = (
                        self.config.config_path.parent / library_path
                    ).resolve()

            else:
                logger.warning(
                    f"Unknown library type '{lib_type}' for library '{name}'"
                )
                continue

            # Check if library path exists
            if not library_path.exists():
                if lib_type == "git":
                    logger.warning(
                        f"Library '{name}' not found at {library_path}. "
                        f"Run 'repo update' to sync libraries."
                    )
                else:
                    logger.warning(
                        f"Static library '{name}' not found at {library_path}"
                    )
                continue

            # Create Library instance with type and priority based on order (first = highest priority)
            priority = len(library_configs) - i
            libraries.append(
                Library(
                    name=name,
                    path=library_path,
                    priority=priority,
                    library_type=lib_type,
                )
            )
            logger.debug(
                f"Loaded {lib_type} library '{name}' from {library_path} with priority {priority}"
            )

        if not libraries:
            logger.warning("No libraries loaded. Run 'repo update' to sync libraries.")

        return libraries

    def find_by_id(
        self, module_name: str, template_id: str
    ) -> Optional[tuple[Path, str]]:
        """Find a template by its ID across all libraries.

        Supports both simple IDs and qualified IDs (template.library format).

        Args:
            module_name: The module name (e.g., 'compose', 'terraform')
            template_id: The template ID to find (simple or qualified)

        Returns:
            Tuple of (template_path, library_name) if found, None otherwise
        """
        logger.debug(
            f"Searching for template '{template_id}' in module '{module_name}' across all libraries"
        )

        # Check if this is a qualified ID (contains '.')
        if "." in template_id:
            parts = template_id.rsplit(".", 1)
            if len(parts) == 2:
                base_id, requested_lib = parts
                logger.debug(
                    f"Parsing qualified ID: base='{base_id}', library='{requested_lib}'"
                )

                # Try to find in the specific library
                for library in self.libraries:
                    if library.name == requested_lib:
                        try:
                            template_path, lib_name = library.find_by_id(
                                module_name, base_id
                            )
                            logger.debug(
                                f"Found template '{base_id}' in library '{requested_lib}'"
                            )
                            return template_path, lib_name
                        except TemplateNotFoundError:
                            logger.debug(
                                f"Template '{base_id}' not found in library '{requested_lib}'"
                            )
                            return None

                logger.debug(f"Library '{requested_lib}' not found")
                return None

        # Simple ID - search by priority
        for library in sorted(self.libraries, key=lambda x: x.priority, reverse=True):
            try:
                template_path, lib_name = library.find_by_id(module_name, template_id)
                logger.debug(
                    f"Found template '{template_id}' in library '{library.name}'"
                )
                return template_path, lib_name
            except TemplateNotFoundError:
                # Continue searching in next library
                continue

        logger.debug(f"Template '{template_id}' not found in any library")
        return None

    def find(
        self, module_name: str, sort_results: bool = False
    ) -> list[tuple[Path, str, bool]]:
        """Find templates across all libraries for a specific module.

        Handles duplicates by qualifying IDs with library names when needed.

        Args:
            module_name: The module name (e.g., 'compose', 'terraform')
            sort_results: Whether to return results sorted alphabetically

        Returns:
            List of tuples (template_path, library_name, needs_qualification)
            where needs_qualification is True if the template ID appears in multiple libraries
        """
        logger.debug(
            f"Searching for templates in module '{module_name}' across all libraries"
        )

        all_templates = []

        # Collect templates from all libraries
        for library in sorted(self.libraries, key=lambda x: x.priority, reverse=True):
            try:
                templates = library.find(module_name, sort_results=False)
                all_templates.extend(templates)
                logger.debug(
                    f"Found {len(templates)} templates in library '{library.name}'"
                )
            except (LibraryError, DuplicateTemplateError) as e:
                # DuplicateTemplateError from library.find() should propagate up
                if isinstance(e, DuplicateTemplateError):
                    raise
                logger.debug(
                    f"Module '{module_name}' not found in library '{library.name}'"
                )
                continue

        # Track template IDs and their libraries to detect cross-library duplicates
        id_to_occurrences = {}
        for template_path, library_name in all_templates:
            template_id = template_path.name
            if template_id not in id_to_occurrences:
                id_to_occurrences[template_id] = []
            id_to_occurrences[template_id].append((template_path, library_name))

        # Build result with qualification markers for duplicates
        result = []
        for template_id, occurrences in id_to_occurrences.items():
            if len(occurrences) > 1:
                # Duplicate across libraries - mark for qualified IDs
                lib_names = ", ".join(lib for _, lib in occurrences)
                logger.info(
                    f"Template '{template_id}' found in multiple libraries: {lib_names}. "
                    f"Using qualified IDs."
                )
                for template_path, library_name in occurrences:
                    # Mark that this ID needs qualification
                    result.append((template_path, library_name, True))
            else:
                # Unique template - no qualification needed
                template_path, library_name = occurrences[0]
                result.append((template_path, library_name, False))

        # Sort if requested
        if sort_results:
            result.sort(key=lambda x: x[0].name.lower())

        logger.debug(f"Found {len(result)} templates total")
        return result