import os

class Config:
    """Application configuration loaded from environment variables."""
    SECRET_KEY = os.environ.get('SECRET_KEY', 'dev-secret-key-change-in-production')
    NEXTCLOUD_URL = os.environ.get('NEXTCLOUD_URL', 'https://nextcloud.sdanywhere.com')

    # Tech users JSON file
    TECH_USERS_FILE = os.environ.get('TECH_USERS_FILE', '/app/data/tech_users.json')

    # Session configuration
    SESSION_TYPE = 'filesystem'
    SESSION_FILE_DIR = '/tmp/flask_session'
    SESSION_PERMANENT = False
    SESSION_USE_SIGNER = True
    SESSION_COOKIE_SAMESITE = 'Strict'
    SESSION_COOKIE_HTTPONLY = True
    SESSION_COOKIE_SECURE = True  # Set to False for local development

    # Upload configuration
    MAX_CONTENT_LENGTH = 50 * 1024 * 1024  # 50MB max upload

    # Development mode
    DEBUG = os.environ.get('FLASK_DEBUG', 'False').lower() == 'true'

class DevelopmentConfig(Config):
    """Development-specific configuration."""
    DEBUG = True
    SESSION_COOKIE_SECURE = False  # Allow HTTP in development

class ProductionConfig(Config):
    """Production-specific configuration."""
    DEBUG = False

    # Ensure these are set in production
    def __init__(self):
        super().__init__()
        if self.SECRET_KEY == 'dev-secret-key-change-in-production':
            raise ValueError("SECRET_KEY must be set in production!")

# Configuration dictionary
config = {
    'development': DevelopmentConfig,
    'production': ProductionConfig,
    'default': DevelopmentConfig
}