"""
Configuration management for StarPunk
Loads settings from environment variables and .env file
"""

import os
from pathlib import Path
from dotenv import load_dotenv


def load_config(app, config_override=None):
    """
    Load configuration into Flask app

    Args:
        app: Flask application instance
        config_override: Optional dict to override config values
    """
    # Load .env file
    load_dotenv()

    # Site configuration
    app.config["SITE_URL"] = os.getenv("SITE_URL", "http://localhost:5000")
    app.config["SITE_NAME"] = os.getenv("SITE_NAME", "StarPunk")
    app.config["SITE_AUTHOR"] = os.getenv("SITE_AUTHOR", "Unknown")
    app.config["SITE_DESCRIPTION"] = os.getenv(
        "SITE_DESCRIPTION", "A minimal IndieWeb CMS"
    )

    # Authentication
    app.config["ADMIN_ME"] = os.getenv("ADMIN_ME")
    app.config["SESSION_SECRET"] = os.getenv("SESSION_SECRET")
    app.config["SESSION_LIFETIME"] = int(os.getenv("SESSION_LIFETIME", "30"))
    app.config["INDIELOGIN_URL"] = os.getenv("INDIELOGIN_URL", "https://indielogin.com")

    # Validate required configuration
    if not app.config["SESSION_SECRET"]:
        raise ValueError(
            "SESSION_SECRET must be set in .env file. "
            'Generate with: python3 -c "import secrets; print(secrets.token_hex(32))"'
        )

    # Flask secret key (uses SESSION_SECRET by default)
    app.config["SECRET_KEY"] = os.getenv(
        "FLASK_SECRET_KEY", app.config["SESSION_SECRET"]
    )

    # Data paths
    app.config["DATA_PATH"] = Path(os.getenv("DATA_PATH", "./data"))
    app.config["NOTES_PATH"] = Path(os.getenv("NOTES_PATH", "./data/notes"))
    app.config["DATABASE_PATH"] = Path(os.getenv("DATABASE_PATH", "./data/starpunk.db"))

    # Flask environment
    app.config["ENV"] = os.getenv("FLASK_ENV", "development")
    app.config["DEBUG"] = os.getenv("FLASK_DEBUG", "1") == "1"

    # Logging
    app.config["LOG_LEVEL"] = os.getenv("LOG_LEVEL", "INFO")

    # Development mode configuration
    app.config["DEV_MODE"] = os.getenv("DEV_MODE", "false").lower() == "true"
    app.config["DEV_ADMIN_ME"] = os.getenv("DEV_ADMIN_ME", "")

    # Application version (use __version__ from package)
    from starpunk import __version__
    app.config["VERSION"] = os.getenv("VERSION", __version__)

    # RSS feed configuration
    app.config["FEED_MAX_ITEMS"] = int(os.getenv("FEED_MAX_ITEMS", "50"))
    app.config["FEED_CACHE_SECONDS"] = int(os.getenv("FEED_CACHE_SECONDS", "300"))

    # Apply overrides if provided
    if config_override:
        app.config.update(config_override)

    # Convert path strings to Path objects (in case overrides provided strings)
    if isinstance(app.config["DATA_PATH"], str):
        app.config["DATA_PATH"] = Path(app.config["DATA_PATH"])
    if isinstance(app.config["NOTES_PATH"], str):
        app.config["NOTES_PATH"] = Path(app.config["NOTES_PATH"])
    if isinstance(app.config["DATABASE_PATH"], str):
        app.config["DATABASE_PATH"] = Path(app.config["DATABASE_PATH"])

    # Validate configuration
    validate_config(app)

    # Ensure data directories exist
    app.config["DATA_PATH"].mkdir(parents=True, exist_ok=True)
    app.config["NOTES_PATH"].mkdir(parents=True, exist_ok=True)


def validate_config(app):
    """
    Validate application configuration on startup

    Ensures required configuration is present based on mode (dev/production)
    and warns prominently if development mode is enabled.

    Args:
        app: Flask application instance

    Raises:
        ValueError: If required configuration is missing
    """
    dev_mode = app.config.get("DEV_MODE", False)

    if dev_mode:
        # Prominently warn about development mode
        app.logger.warning(
            "=" * 60 + "\n"
            "WARNING: Development authentication enabled!\n"
            "This should NEVER be used in production.\n"
            "Set DEV_MODE=false for production deployments.\n" + "=" * 60
        )

        # Require DEV_ADMIN_ME in dev mode
        if not app.config.get("DEV_ADMIN_ME"):
            raise ValueError(
                "DEV_MODE=true requires DEV_ADMIN_ME to be set. "
                "Set DEV_ADMIN_ME=https://your-dev-identity.example.com in .env"
            )
    else:
        # Production mode: ADMIN_ME is required
        if not app.config.get("ADMIN_ME"):
            raise ValueError(
                "Production mode requires ADMIN_ME to be set. "
                "Set ADMIN_ME=https://your-site.com in .env"
            )