"""
Configuration management for ClaudeTools.

This module provides centralized configuration management using pydantic-settings
to load and validate environment variables. All sensitive configuration values
are loaded from environment variables rather than being hardcoded.
"""

from functools import lru_cache

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    """
    Application settings loaded from environment variables.

    All settings are loaded from environment variables or a .env file.
    This ensures sensitive information like database credentials and
    encryption keys are never hardcoded in the source code.

    Attributes:
        DATABASE_URL: Complete database connection URL
        DATABASE_NAME: Database name (for display purposes)
        DATABASE_POOL_SIZE: Number of connections to maintain in the pool
        DATABASE_MAX_OVERFLOW: Maximum number of connections beyond pool_size
        JWT_SECRET_KEY: Secret key for JWT token signing
        ENCRYPTION_KEY: Key for encrypting sensitive data
        JWT_ALGORITHM: Algorithm used for JWT token signing
        ACCESS_TOKEN_EXPIRE_MINUTES: Token expiration time in minutes
        ALLOWED_ORIGINS: Comma-separated list of allowed CORS origins
    """

    # Database configuration
    DATABASE_URL: str
    DATABASE_NAME: str = "claudetools"
    DATABASE_POOL_SIZE: int = 20
    DATABASE_MAX_OVERFLOW: int = 10

    # Security configuration
    JWT_SECRET_KEY: str
    ENCRYPTION_KEY: str
    JWT_ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60

    # API configuration
    ALLOWED_ORIGINS: str = "*"

    class Config:
        """Pydantic configuration."""

        env_file = ".env"
        case_sensitive = True


@lru_cache()
def get_settings() -> Settings:
    """
    Get cached application settings.

    This function uses lru_cache to ensure settings are only loaded once
    and reused throughout the application lifecycle, improving performance
    and ensuring consistency.

    Returns:
        Settings: The application settings instance

    Example:
        ```python
        from api.config import get_settings

        settings = get_settings()
        print(settings.DATABASE_URL)
        ```
    """
    return Settings()