"""Configuration management for gitignore-generator."""
import os
from pathlib import Path
from typing import Any, Dict, List, Optional


class Config:
    """Configuration management class."""

    DEFAULT_CONFIG_NAME = ".gitignorerc"

    def __init__(
        self,
        custom_templates: Optional[Dict[str, str]] = None,
        default_types: Optional[List[str]] = None,
        exclude_patterns: Optional[List[str]] = None,
        include_patterns: Optional[List[str]] = None,
    ) -> None:
        """Initialize configuration."""
        self.custom_templates = custom_templates or {}
        self.default_types = default_types or []
        self.exclude_patterns = exclude_patterns or []
        self.include_patterns = include_patterns or {}

    @classmethod
    def load(cls, config_path: str) -> "Config":
        """Load configuration from YAML file."""
        import yaml

        path = Path(config_path)
        if not path.exists():
            raise FileNotFoundError(f"Config file not found: {config_path}")

        try:
            with open(path, "r") as f:
                data = yaml.safe_load(f)
        except yaml.YAMLError as e:
            raise ValueError(f"Invalid YAML in config file: {e}")
        except OSError as e:
            raise OSError(f"Error reading config file: {e}")

        if not isinstance(data, dict):
            raise ValueError("Config file must contain a YAML dictionary")

        custom_templates = data.get("custom_templates", {})
        default_types = data.get("default_types", [])
        exclude_patterns = data.get("exclude_patterns", [])
        include_patterns = data.get("include_patterns", {})

        return cls(
            custom_templates=custom_templates,
            default_types=default_types,
            exclude_patterns=exclude_patterns,
            include_patterns=include_patterns,
        )

    @classmethod
    def find_config(
        cls, search_paths: Optional[List[str]] = None
    ) -> Optional[Path]:
        """Find configuration file in search paths."""
        if search_paths is None:
            search_paths = [
                os.getcwd(),
                os.path.expanduser("~"),
                "/etc",
            ]

        for path_str in search_paths:
            path = Path(path_str)
            config_path = path / cls.DEFAULT_CONFIG_NAME
            if config_path.exists():
                return config_path

            yaml_path = path / "config.yaml"
            if yaml_path.exists():
                return yaml_path

        return None

    def save(self, config_path: str) -> None:
        """Save configuration to YAML file."""
        import yaml

        path = Path(config_path)

        data = {
            "custom_templates": self.custom_templates,
            "default_types": self.default_types,
            "exclude_patterns": self.exclude_patterns,
            "include_patterns": self.include_patterns,
        }

        try:
            with open(path, "w") as f:
                yaml.dump(data, f, default_flow_style=False, indent=2)
        except OSError as e:
            raise OSError(f"Error writing config file: {e}")

    def get(self, key: str, default: Any = None) -> Any:
        """Get configuration value."""
        if hasattr(self, key):
            return getattr(self, key)
        return default

    def set(self, key: str, value: Any) -> None:
        """Set configuration value."""
        if hasattr(self, key):
            setattr(self, key, value)

    def merge(self, other: "Config") -> "Config":
        """Merge with another configuration."""
        return Config(
            custom_templates={
                **self.custom_templates,
                **other.custom_templates,
            },
            default_types=self.default_types or other.default_types,
            exclude_patterns=list(
                set(self.exclude_patterns + other.exclude_patterns)
            ),
            include_patterns={
                **self.include_patterns,
                **other.include_patterns,
            },
        )

    def validate(self) -> List[str]:
        """Validate configuration and return list of errors."""
        errors = []

        if not isinstance(self.custom_templates, dict):
            errors.append("custom_templates must be a dictionary")
        else:
            for key, value in self.custom_templates.items():
                if not isinstance(key, str):
                    errors.append(f"Template key must be string: {key}")
                if not isinstance(value, str):
                    errors.append(
                        f"Template value for '{key}' must be a string"
                    )

        if not isinstance(self.default_types, list):
            errors.append("default_types must be a list")
        else:
            for item in self.default_types:
                if not isinstance(item, str):
                    errors.append(f"Default type must be string: {item}")

        if not isinstance(self.exclude_patterns, list):
            errors.append("exclude_patterns must be a list")
        else:
            for item in self.exclude_patterns:
                if not isinstance(item, str):
                    errors.append(
                        f"Exclude pattern must be string: {item}"
                    )

        if not isinstance(self.include_patterns, dict):
            errors.append("include_patterns must be a dictionary")
        else:
            for key, value in self.include_patterns.items():
                if not isinstance(key, str):
                    errors.append(f"Include pattern key must be string: {key}")
                if isinstance(value, list):
                    for item in value:
                        if not isinstance(item, str):
                            errors.append(
                                f"Include pattern value for '{key}' must be string: {item}"
                            )
                elif not isinstance(value, str):
                    errors.append(
                        f"Include pattern value for '{key}' must be string or list"
                    )

        return errors

    def to_dict(self) -> Dict[str, Any]:
        """Convert configuration to dictionary."""
        return {
            "custom_templates": self.custom_templates,
            "default_types": self.default_types,
            "exclude_patterns": self.exclude_patterns,
            "include_patterns": self.include_patterns,
        }

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> "Config":
        """Create configuration from dictionary."""
        return cls(
            custom_templates=data.get("custom_templates", {}),
            default_types=data.get("default_types", []),
            exclude_patterns=data.get("exclude_patterns", []),
            include_patterns=data.get("include_patterns", {}),
        )