"""Configuration management for git-commit-message-generator."""
import os
from pathlib import Path
from typing import Optional

import yaml


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

    def __init__(self, config_path: Optional[str] = None):
        """Initialize configuration.

        Args:
            config_path: Path to config file. Defaults to None.
        """
        self.config_path = config_path or os.environ.get(
            "GIT_COMMIT_GENERATOR_CONFIG"
        )
        self._config = self._load_config()

    def _load_config(self) -> dict:
        """Load configuration from file.

        Returns:
            Dictionary containing configuration.
        """
        config = {
            "ollama_host": os.environ.get("OLLAMA_HOST", "http://localhost:11434"),
            "ollama_model": os.environ.get("OLLAMA_MODEL", "llama3"),
            "prompt_dir": os.environ.get(
                "PROMPT_DIR", str(Path(__file__).parent.parent / "prompts")
            ),
        }

        if self.config_path:
            config_file = Path(self.config_path)
            if config_file.exists():
                with open(config_file, "r") as f:
                    file_config = yaml.safe_load(f) or {}
                config.update(file_config)

        return config

    @property
    def ollama_host(self) -> str:
        """Get Ollama host URL.

        Returns:
            Ollama host URL.
        """
        return self._config["ollama_host"]

    @property
    def ollama_model(self) -> str:
        """Get default Ollama model.

        Returns:
            Ollama model name.
        """
        return self._config["ollama_model"]

    @property
    def prompt_dir(self) -> str:
        """Get prompt directory path.

        Returns:
            Path to prompt templates directory.
        """
        return self._config["prompt_dir"]

    def get_prompt_path(self, prompt_name: str) -> Path:
        """Get full path to a prompt file.

        Args:
            prompt_name: Name of the prompt file.

        Returns:
            Full path to the prompt file.
        """
        return Path(self.prompt_dir) / prompt_name

    def read_prompt(self, prompt_name: str) -> str:
        """Read a prompt template file.

        Args:
            prompt_name: Name of the prompt file.

        Returns:
            Content of the prompt file.
        """
        prompt_path = self.get_prompt_path(prompt_name)
        if prompt_path.exists():
            with open(prompt_path, "r") as f:
                return f.read()
        return ""


def get_config(config_path: Optional[str] = None) -> Config:
    """Get configuration instance.

    Args:
        config_path: Optional path to config file.

    Returns:
        Config instance.
    """
    return Config(config_path)