import os
import secrets


class Config:
    SECRET_KEY = os.environ.get('FLASK_SECRET_KEY', secrets.token_hex(32))
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SESSION_COOKIE_HTTPONLY = True
    SESSION_COOKIE_SAMESITE = 'Lax'

    # Database
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', 'mysql+pymysql://root:@localhost:3306/aldudu_academy')
    
    # Database Connection Pooling
    SQLALCHEMY_ENGINE_OPTIONS = {
        'pool_size': int(os.environ.get('DB_POOL_SIZE', '10')),
        'pool_recycle': int(os.environ.get('DB_POOL_RECYCLE', '3600')),
        'pool_pre_ping': os.environ.get('DB_POOL_PRE_PING', 'true').lower() == 'true',
        'max_overflow': int(os.environ.get('DB_MAX_OVERFLOW', '20')),
    }

    # Mail
    MAIL_SERVER = os.environ.get('MAIL_SERVER', 'sandbox.smtp.mailtrap.io')
    MAIL_PORT = int(os.environ.get('MAIL_PORT', '2525'))
    MAIL_USE_TLS = os.environ.get('MAIL_USE_TLS', 'true').lower() == 'true'
    MAIL_USERNAME = os.environ.get('MAIL_USERNAME', '')
    MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD', '')
    MAIL_DEFAULT_SENDER = (
        os.environ.get('MAIL_SENDER_NAME', 'Aldudu Academy'),
        os.environ.get('MAIL_SENDER_EMAIL', 'noreply@aldudu.academy')
    )

    # Cache - Use RedisCache in production, SimpleCache in development
    CACHE_TYPE = os.environ.get('CACHE_TYPE', 'SimpleCache')
    CACHE_DEFAULT_TIMEOUT = int(os.environ.get('CACHE_DEFAULT_TIMEOUT', '300'))
    CACHE_REDIS_HOST = os.environ.get('CACHE_REDIS_HOST', 'localhost')
    CACHE_REDIS_PORT = int(os.environ.get('CACHE_REDIS_PORT', '6379'))
    CACHE_REDIS_DB = int(os.environ.get('CACHE_REDIS_DB', '1'))
    CACHE_REDIS_URL = f"redis://{CACHE_REDIS_HOST}:{CACHE_REDIS_PORT}/{CACHE_REDIS_DB}"

    # App
    APP_URL = os.environ.get('APP_URL', 'http://localhost:5000')

    # File Upload Security
    MAX_CONTENT_LENGTH = int(os.environ.get('MAX_CONTENT_LENGTH', '16777216'))  # 16MB default
    ALLOWED_EXTENSIONS = {'pdf', 'doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx',
                          'png', 'jpg', 'jpeg', 'gif', 'webp',
                          'txt', 'rtf', 'zip', 'rar', '7z'}
    UPLOAD_FOLDER = os.path.join(os.getcwd(), 'instance', 'uploads')


class DevelopmentConfig(Config):
    DEBUG = True


class ProductionConfig(Config):
    DEBUG = False
    SESSION_COOKIE_SECURE = True


class TestingConfig(Config):
    TESTING = True
    SQLALCHEMY_DATABASE_URI = 'sqlite:///test.db'


config_by_name = {
    'development': DevelopmentConfig,
    'production': ProductionConfig,
    'testing': TestingConfig,
}