ChristianLempa_Boilerplates/cli/core/config/config_manager.py

from __future__ import annotations

import logging
import shutil
import tempfile
from dataclasses import dataclass
from pathlib import Path
from typing import Any, ClassVar

import yaml

from ..exceptions import ConfigError, ConfigValidationError, YAMLParseError

logger = logging.getLogger(__name__)

DEFAULT_LIBRARY_NAME = "default"
DEFAULT_LIBRARY_DIRECTORY = "."
DEFAULT_LIBRARY_BRANCH = "main"
DEFAULT_LIBRARY_URL = "https://github.com/christianlempa/boilerplates-library.git"
LEGACY_DEFAULT_LIBRARY_DIRECTORY = "library"
LEGACY_DEFAULT_LIBRARY_URL = "https://github.com/christianlempa/boilerplates.git"


@dataclass
class MigrationNotice:
    """Represents a user-visible config migration notice."""

    kind: str
    message: str


@dataclass
class LibraryConfig:
    """Configuration for a template library."""

    name: str
    library_type: str = "git"
    url: str | None = None
    directory: str | None = None
    branch: str = "main"
    path: str | None = None
    enabled: bool = True


class ConfigManager:
    """Manages configuration for the CLI application."""

    _pending_migration_notices: ClassVar[list[MigrationNotice]] = []

    def __init__(self, config_path: str | Path | None = None) -> None:
        """Initialize the configuration manager.

        Args:
            config_path: Path to the configuration file. If None, auto-detects:
                        1. Checks for ./config.yaml (local project config)
                        2. Falls back to ~/.config/boilerplates/config.yaml (global config)
        """
        if config_path is None:
            # Check for local config.yaml in current directory first
            local_config = Path.cwd() / "config.yaml"
            if local_config.exists() and local_config.is_file():
                self.config_path = local_config
                self.is_local = True
                logger.debug(f"Using local config: {local_config}")
            else:
                # Fall back to global config
                config_dir = Path.home() / ".config" / "boilerplates"
                config_dir.mkdir(parents=True, exist_ok=True)
                self.config_path = config_dir / "config.yaml"
                self.is_local = False
        else:
            self.config_path = Path(config_path)
            self.is_local = False

        # Create default config if it doesn't exist (only for global config)
        if not self.config_path.exists():
            if not self.is_local:
                self._create_default_config()
            else:
                raise ConfigError(f"Local config file not found: {self.config_path}")
        else:
            # Migrate existing config if needed
            self._migrate_config_if_needed()

    def _create_default_config(self) -> None:
        """Create a default configuration file."""
        default_config = {
            "defaults": {},
            "preferences": {"editor": "vim", "output_dir": None, "library_paths": []},
            "libraries": [
                {
                    "name": DEFAULT_LIBRARY_NAME,
                    "type": "git",
                    "url": DEFAULT_LIBRARY_URL,
                    "branch": DEFAULT_LIBRARY_BRANCH,
                    "directory": DEFAULT_LIBRARY_DIRECTORY,
                    "enabled": True,
                }
            ],
        }
        self._write_config(default_config)
        logger.info(f"Created default configuration at {self.config_path}")

    def _migrate_config_if_needed(self) -> None:
        """Migrate existing config to add missing sections and library types."""
        try:
            config = self._read_config()
            needs_migration = False

            # Add libraries section if missing
            if "libraries" not in config:
                logger.info("Migrating config: adding libraries section")
                config["libraries"] = [
                    {
                        "name": DEFAULT_LIBRARY_NAME,
                        "type": "git",
                        "url": DEFAULT_LIBRARY_URL,
                        "branch": DEFAULT_LIBRARY_BRANCH,
                        "directory": DEFAULT_LIBRARY_DIRECTORY,
                        "enabled": True,
                    }
                ]
                needs_migration = True
            else:
                # Migrate existing libraries to add 'type' field if missing
                # For backward compatibility, assume all old libraries without
                # 'type' are git libraries
                libraries = config.get("libraries", [])
                for library in libraries:
                    if "type" not in library:
                        lib_name = library.get("name", "unknown")
                        logger.info(f"Migrating library '{lib_name}': adding type: git")
                        library["type"] = "git"
                        needs_migration = True

            default_library_migrated = self._migrate_default_library(config)
            needs_migration = needs_migration or default_library_migrated

            # Write back if migration was needed
            if needs_migration:
                self._write_config(config)
                logger.info("Config migration completed successfully")
        except (ConfigError, ConfigValidationError, YAMLParseError):
            raise
        except Exception as e:
            logger.error(f"Config migration failed: {e}")
            raise ConfigError(f"Failed to migrate configuration '{self.config_path}': {e}") from e

    def _migrate_default_library(self, config: dict[str, Any]) -> bool:
        """Rewrite the built-in default git library entry to the 0.2.0 library repo."""
        libraries = config.get("libraries", [])
        migrated = False

        for library in libraries:
            if library.get("name") != DEFAULT_LIBRARY_NAME:
                continue

            if library.get("type", "git") != "git":
                continue

            if library.get("url") != LEGACY_DEFAULT_LIBRARY_URL:
                continue

            if library.get("directory", LEGACY_DEFAULT_LIBRARY_DIRECTORY) != LEGACY_DEFAULT_LIBRARY_DIRECTORY:
                continue

            target_state = {
                "url": DEFAULT_LIBRARY_URL,
                "directory": DEFAULT_LIBRARY_DIRECTORY,
            }

            changed = any(library.get(key) != value for key, value in target_state.items())
            if not changed:
                break

            previous_location = library.get("url") or library.get("path") or "<unknown>"
            library.update(target_state)
            migrated = True
            logger.info(
                "Migrated default library from %s to %s (%s)",
                previous_location,
                DEFAULT_LIBRARY_URL,
                DEFAULT_LIBRARY_DIRECTORY,
            )
            self._add_migration_notice(
                kind="default_library_repo",
                message=(
                    "Your default template library was migrated to "
                    "christianlempa/boilerplates-library. "
                    "Run 'boilerplates repo update' to sync the new templates."
                ),
            )
            break

        return migrated

    @classmethod
    def _add_migration_notice(cls, kind: str, message: str) -> None:
        """Queue a migration notice for later display in the CLI layer."""
        if any(notice.kind == kind and notice.message == message for notice in cls._pending_migration_notices):
            return
        cls._pending_migration_notices.append(MigrationNotice(kind=kind, message=message))

    @classmethod
    def consume_migration_notices(cls) -> list[MigrationNotice]:
        """Return and clear pending migration notices."""
        notices = cls._pending_migration_notices.copy()
        cls._pending_migration_notices.clear()
        return notices

    def _read_config(self) -> dict[str, Any]:
        """Read configuration from file.

        Returns:
            Dictionary containing the configuration.

        Raises:
            YAMLParseError: If YAML parsing fails.
            ConfigValidationError: If configuration structure is invalid.
            ConfigError: If reading fails for other reasons.
        """
        try:
            with self.config_path.open() as f:
                config = yaml.safe_load(f) or {}

            # Validate config structure
            self._validate_config_structure(config)

            return config
        except yaml.YAMLError as e:
            logger.error(f"Failed to parse YAML configuration: {e}")
            raise YAMLParseError(str(self.config_path), e) from e
        except ConfigValidationError:
            # Re-raise validation errors as-is
            raise
        except OSError as e:
            logger.error(f"Failed to read configuration file: {e}")
            raise ConfigError(f"Failed to read configuration file '{self.config_path}': {e}") from e

    def _write_config(self, config: dict[str, Any]) -> None:
        """Write configuration to file atomically using temp file + rename pattern.

        This prevents config file corruption if write operation fails partway through.

        Args:
            config: Dictionary containing the configuration to write.

        Raises:
            ConfigValidationError: If configuration structure is invalid.
            ConfigError: If writing fails for any reason.
        """
        tmp_path = None
        try:
            # Validate config structure before writing
            self._validate_config_structure(config)

            # Ensure parent directory exists
            self.config_path.parent.mkdir(parents=True, exist_ok=True)

            # Write to temporary file in same directory for atomic rename
            with tempfile.NamedTemporaryFile(
                mode="w",
                delete=False,
                dir=self.config_path.parent,
                prefix=".config_",
                suffix=".tmp",
            ) as tmp_file:
                yaml.dump(config, tmp_file, default_flow_style=False)
                tmp_path = tmp_file.name

            # Atomic rename (overwrites existing file on POSIX systems)
            shutil.move(tmp_path, self.config_path)
            logger.debug(f"Configuration written atomically to {self.config_path}")

        except ConfigValidationError:
            # Re-raise validation errors as-is
            if tmp_path:
                Path(tmp_path).unlink(missing_ok=True)
            raise
        except (OSError, yaml.YAMLError) as e:
            # Clean up temp file if it exists
            if tmp_path:
                try:
                    Path(tmp_path).unlink(missing_ok=True)
                except OSError:
                    logger.warning(f"Failed to clean up temporary file: {tmp_path}")
            logger.error(f"Failed to write configuration file: {e}")
            raise ConfigError(f"Failed to write configuration to '{self.config_path}': {e}") from e

    def _validate_config_structure(self, config: dict[str, Any]) -> None:
        """Validate the configuration structure - basic type checking.

        Args:
            config: Configuration dictionary to validate.

        Raises:
            ConfigValidationError: If configuration structure is invalid.
        """
        if not isinstance(config, dict):
            raise ConfigValidationError("Configuration must be a dictionary")

        # Validate top-level types
        self._validate_top_level_types(config)

        # Validate defaults structure
        self._validate_defaults_types(config)

        # Validate libraries structure
        self._validate_libraries_fields(config)

    def _validate_top_level_types(self, config: dict[str, Any]) -> None:
        """Validate top-level config section types."""
        if "defaults" in config and not isinstance(config["defaults"], dict):
            raise ConfigValidationError("'defaults' must be a dictionary")

        if "preferences" in config and not isinstance(config["preferences"], dict):
            raise ConfigValidationError("'preferences' must be a dictionary")

        if "libraries" in config and not isinstance(config["libraries"], list):
            raise ConfigValidationError("'libraries' must be a list")

    def _validate_defaults_types(self, config: dict[str, Any]) -> None:
        """Validate defaults section has correct types."""
        if "defaults" not in config:
            return

        for module_name, module_defaults in config["defaults"].items():
            if not isinstance(module_defaults, dict):
                raise ConfigValidationError(f"Defaults for module '{module_name}' must be a dictionary")

    def _validate_libraries_fields(self, config: dict[str, Any]) -> None:
        """Validate libraries have required fields."""
        if "libraries" not in config:
            return

        for i, library in enumerate(config["libraries"]):
            if not isinstance(library, dict):
                raise ConfigValidationError(f"Library at index {i} must be a dictionary")

            if "name" not in library:
                raise ConfigValidationError(f"Library at index {i} missing required field 'name'")

            lib_type = library.get("type", "git")
            if lib_type == "git" and ("url" not in library or "directory" not in library):
                raise ConfigValidationError(
                    f"Git library at index {i} missing required fields 'url' and/or 'directory'"
                )
            if lib_type == "static" and "path" not in library:
                raise ConfigValidationError(f"Static library at index {i} missing required field 'path'")

    def get_config_path(self) -> Path:
        """Get the path to the configuration file being used.

        Returns:
            Path to the configuration file (global or local).
        """
        return self.config_path

    def is_using_local_config(self) -> bool:
        """Check if a local configuration file is being used.

        Returns:
            True if using local config, False if using global config.
        """
        return self.is_local

    def get_defaults(self, module_name: str) -> dict[str, Any]:
        """Get default variable values for a module.

        Returns defaults in a flat format:
        {
            "var_name": "value",
            "var2_name": "value2"
        }

        Args:
            module_name: Name of the module

        Returns:
            Dictionary of default values (flat key-value pairs)
        """
        config = self._read_config()
        defaults = config.get("defaults", {})
        return defaults.get(module_name, {})

    def set_defaults(self, module_name: str, defaults: dict[str, Any]) -> None:
        """Set default variable values for a module with comprehensive validation.

        Args:
            module_name: Name of the module
            defaults: Dictionary of defaults (flat key-value pairs):
                      {"var_name": "value", "var2_name": "value2"}

        Raises:
            ConfigValidationError: If module name or variable names are invalid.
        """
        # Basic validation
        if not isinstance(module_name, str) or not module_name:
            raise ConfigValidationError("Module name must be a non-empty string")

        if not isinstance(defaults, dict):
            raise ConfigValidationError("Defaults must be a dictionary")

        config = self._read_config()

        if "defaults" not in config:
            config["defaults"] = {}

        config["defaults"][module_name] = defaults
        self._write_config(config)
        logger.info(f"Updated defaults for module '{module_name}'")

    def set_default_value(self, module_name: str, var_name: str, value: Any) -> None:
        """Set a single default variable value with comprehensive validation.

        Args:
            module_name: Name of the module
            var_name: Name of the variable
            value: Default value to set

        Raises:
            ConfigValidationError: If module name or variable name is invalid.
        """
        # Basic validation
        if not isinstance(module_name, str) or not module_name:
            raise ConfigValidationError("Module name must be a non-empty string")

        if not isinstance(var_name, str) or not var_name:
            raise ConfigValidationError("Variable name must be a non-empty string")

        defaults = self.get_defaults(module_name)
        defaults[var_name] = value
        self.set_defaults(module_name, defaults)
        logger.info(f"Set default for '{module_name}.{var_name}' = '{value}'")

    def get_default_value(self, module_name: str, var_name: str) -> Any | None:
        """Get a single default variable value.

        Args:
            module_name: Name of the module
            var_name: Name of the variable

        Returns:
            Default value or None if not set
        """
        defaults = self.get_defaults(module_name)
        return defaults.get(var_name)

    def clear_defaults(self, module_name: str) -> None:
        """Clear all defaults for a module.

        Args:
            module_name: Name of the module
        """
        config = self._read_config()

        if "defaults" in config and module_name in config["defaults"]:
            del config["defaults"][module_name]
            self._write_config(config)
            logger.info(f"Cleared defaults for module '{module_name}'")

    def get_preference(self, key: str) -> Any | None:
        """Get a user preference value.

        Args:
            key: Preference key (e.g., 'editor', 'output_dir', 'library_paths')

        Returns:
            Preference value or None if not set
        """
        config = self._read_config()
        preferences = config.get("preferences", {})
        return preferences.get(key)

    def set_preference(self, key: str, value: Any) -> None:
        """Set a user preference value with comprehensive validation.

        Args:
            key: Preference key
            value: Preference value

        Raises:
            ConfigValidationError: If key or value is invalid for known preference types.
        """
        # Basic validation
        if not isinstance(key, str) or not key:
            raise ConfigValidationError("Preference key must be a non-empty string")

        config = self._read_config()

        if "preferences" not in config:
            config["preferences"] = {}

        config["preferences"][key] = value
        self._write_config(config)
        logger.info(f"Set preference '{key}' = '{value}'")

    def get_all_preferences(self) -> dict[str, Any]:
        """Get all user preferences.

        Returns:
            Dictionary of all preferences
        """
        config = self._read_config()
        return config.get("preferences", {})

    def get_libraries(self) -> list[dict[str, Any]]:
        """Get all configured libraries.

        Returns:
            List of library configurations
        """
        config = self._read_config()
        return config.get("libraries", [])

    def get_library_by_name(self, name: str) -> dict[str, Any] | None:
        """Get a specific library by name.

        Args:
            name: Name of the library

        Returns:
            Library configuration dictionary or None if not found
        """
        libraries = self.get_libraries()
        for library in libraries:
            if library.get("name") == name:
                return library
        return None

    def add_library(self, lib_config: LibraryConfig) -> None:
        """Add a new library to the configuration.

        Args:
            lib_config: Library configuration

        Raises:
            ConfigValidationError: If library with the same name already exists or validation fails
        """
        # Basic validation
        if not isinstance(lib_config.name, str) or not lib_config.name:
            raise ConfigValidationError("Library name must be a non-empty string")

        if lib_config.library_type not in ("git", "static"):
            raise ConfigValidationError(f"Library type must be 'git' or 'static', got '{lib_config.library_type}'")

        if self.get_library_by_name(lib_config.name):
            raise ConfigValidationError(f"Library '{lib_config.name}' already exists")

        # Type-specific validation
        if lib_config.library_type == "git":
            if not lib_config.url or not lib_config.directory:
                raise ConfigValidationError("Git libraries require 'url' and 'directory' parameters")

            library_dict = {
                "name": lib_config.name,
                "type": "git",
                "url": lib_config.url,
                "branch": lib_config.branch,
                "directory": lib_config.directory,
                "enabled": lib_config.enabled,
            }

        else:  # static
            if not lib_config.path:
                raise ConfigValidationError("Static libraries require 'path' parameter")

            # For backward compatibility with older CLI versions,
            # add dummy values for git-specific fields
            library_dict = {
                "name": lib_config.name,
                "type": "static",
                "url": "",  # Empty string for backward compatibility
                "branch": "main",  # Default value for backward compatibility
                "directory": ".",  # Default value for backward compatibility
                "path": lib_config.path,
                "enabled": lib_config.enabled,
            }

        config = self._read_config()

        if "libraries" not in config:
            config["libraries"] = []

        config["libraries"].append(library_dict)

        self._write_config(config)
        logger.info(f"Added {lib_config.library_type} library '{lib_config.name}'")

    def remove_library(self, name: str) -> None:
        """Remove a library from the configuration.

        Args:
            name: Name of the library to remove

        Raises:
            ConfigError: If library is not found
        """
        config = self._read_config()
        libraries = config.get("libraries", [])

        # Find and remove the library
        new_libraries = [lib for lib in libraries if lib.get("name") != name]

        if len(new_libraries) == len(libraries):
            raise ConfigError(f"Library '{name}' not found")

        config["libraries"] = new_libraries
        self._write_config(config)
        logger.info(f"Removed library '{name}'")

    def update_library(self, name: str, **kwargs: Any) -> None:
        """Update a library's configuration.

        Args:
            name: Name of the library to update
            **kwargs: Fields to update (url, branch, directory, enabled)

        Raises:
            ConfigError: If library is not found
            ConfigValidationError: If validation fails
        """
        config = self._read_config()
        libraries = config.get("libraries", [])

        # Find the library
        library_found = False
        for library in libraries:
            if library.get("name") == name:
                library_found = True

                # Update allowed fields
                if "url" in kwargs:
                    library["url"] = kwargs["url"]

                if "branch" in kwargs:
                    library["branch"] = kwargs["branch"]

                if "directory" in kwargs:
                    library["directory"] = kwargs["directory"]

                if "enabled" in kwargs:
                    library["enabled"] = kwargs["enabled"]

                break

        if not library_found:
            raise ConfigError(f"Library '{name}' not found")

        config["libraries"] = libraries
        self._write_config(config)
        logger.info(f"Updated library '{name}'")

    def get_libraries_path(self) -> Path:
        """Get the path to the libraries directory.

        Returns:
            Path to the libraries directory (same directory as config file)
        """
        return self.config_path.parent / "libraries"