"""YAML format converter."""

from pathlib import Path
from typing import Any, Dict, Union

import yaml

from config_converter.converters.base import BaseConverter, ConversionError


class YamlConverter(BaseConverter):
    """Converter for YAML configuration files."""

    FORMAT_NAME = "yaml"
    FILE_EXTENSIONS = ["yaml", "yml"]

    def read(self, source: Union[str, Path]) -> Dict[str, Any]:
        """Read and parse a YAML configuration file."""
        try:
            with open(source, "r", encoding="utf-8") as f:
                return yaml.safe_load(f) or {}
        except yaml.YAMLError as e:
            raise ConversionError(f"Invalid YAML in {source}: {e}") from e
        except FileNotFoundError as e:
            raise ConversionError(f"File not found: {source}") from e
        except PermissionError as e:
            raise ConversionError(f"Permission denied: {source}") from e

    def write(self, data: Dict[str, Any], target: Union[str, Path]) -> None:
        """Write configuration data to a YAML file."""
        try:
            with open(target, "w", encoding="utf-8") as f:
                yaml.dump(data, f, default_flow_style=False, allow_unicode=True, sort_keys=False)
        except (OSError, TypeError) as e:
            raise ConversionError(f"Failed to write YAML to {target}: {e}") from e

    def parse(self, content: str) -> Dict[str, Any]:
        """Parse YAML content from a string."""
        try:
            return yaml.safe_load(content) or {}
        except yaml.YAMLError as e:
            raise ConversionError(f"Invalid YAML content: {e}") from e

    def format(self, data: Dict[str, Any]) -> str:
        """Format configuration data to a YAML string."""
        try:
            return yaml.dump(data, default_flow_style=False, allow_unicode=True, sort_keys=False)
        except (TypeError, ValueError) as e:
            raise ConversionError(f"Failed to format data as YAML: {e}") from e