config.py

"""
Configuration management for URL Shortener
Supports multiple environments: development, testing, production
"""
import os
from typing import Optional
from dotenv import load_dotenv

# Load environment variables
load_dotenv()


class Config:
    """Base configuration"""
    
    # Application
    APP_NAME = "url-shortener"
    ENV = os.getenv("FLASK_ENV", "development")
    DEBUG = os.getenv("DEBUG", "False").lower() == "true"
    SECRET_KEY = os.getenv("SECRET_KEY", "dev-secret-key-change-in-production")
    
    # Server
    HOST = os.getenv("HOST", "0.0.0.0")
    PORT = int(os.getenv("PORT", "5000"))
    
    # Redis
    REDIS_HOST = os.getenv("REDIS_HOST", "redis")
    REDIS_PORT = int(os.getenv("REDIS_PORT", "6379"))
    REDIS_DB = int(os.getenv("REDIS_DB", "0"))
    REDIS_PASSWORD = os.getenv("REDIS_PASSWORD")
    REDIS_MAX_CONNECTIONS = int(os.getenv("REDIS_MAX_CONNECTIONS", "50"))
    
    # MySQL/Database
    DB_HOST = os.getenv("MYSQL_HOST", "db")
    DB_PORT = int(os.getenv("MYSQL_PORT", "3306"))
    DB_USER = os.getenv("MYSQL_USER", "root")
    DB_PASSWORD = os.getenv("MYSQL_PASSWORD", "example")
    DB_DATABASE = os.getenv("MYSQL_DB", "urlshortener")
    DB_POOL_SIZE = int(os.getenv("MYSQL_POOL_SIZE", "10"))
    DB_POOL_RECYCLE = int(os.getenv("MYSQL_POOL_RECYCLE", "3600"))
    DB_POOL_TIMEOUT = int(os.getenv("MYSQL_POOL_TIMEOUT", "30"))
    
    # Celery
    CELERY_BROKER_URL = f"redis://{REDIS_HOST}:{REDIS_PORT}/0"
    CELERY_RESULT_BACKEND = f"redis://{REDIS_HOST}:{REDIS_PORT}/0"
    CELERY_TASK_SERIALIZER = "json"
    CELERY_RESULT_SERIALIZER = "json"
    CELERY_ACCEPT_CONTENT = ["json"]
    CELERY_TIMEZONE = "UTC"
    CELERY_ENABLE_UTC = True
    CELERY_TASK_TRACK_STARTED = True
    CELERY_TASK_TIME_LIMIT = 30 * 60  # 30 minutes
    CELERY_TASK_SOFT_TIME_LIMIT = 25 * 60  # 25 minutes
    
    # JWT
    JWT_PRIVATE_KEY_PATH = os.getenv("JWT_PRIVATE_KEY", "private.pem")
    JWT_PUBLIC_KEY_PATH = os.getenv("JWT_PUBLIC_KEY", "public.pem")
    JWT_ALGORITHM = os.getenv("JWT_ALGORITHM", "RS256")
    JWT_ACCESS_TOKEN_EXPIRES = int(os.getenv("JWT_ACCESS_TOKEN_EXPIRES", "900"))  # 15 minutes
    JWT_REFRESH_TOKEN_EXPIRES = int(os.getenv("JWT_REFRESH_TOKEN_EXPIRES", "2592000"))  # 30 days
    JWT_ISSUER = os.getenv("JWT_ISSUER", "url-shortener.com")
    JWT_AUDIENCE = os.getenv("JWT_AUDIENCE", "url-shortener.com")
    
    # Rate Limiting
    RATE_LIMIT_PER_MINUTE = int(os.getenv("RATE_LIMIT_PER_MINUTE", "60"))
    RATE_LIMIT_PER_HOUR = int(os.getenv("RATE_LIMIT_PER_HOUR", "1000"))
    RATE_LIMIT_STORAGE_URL = f"redis://{REDIS_HOST}:{REDIS_PORT}/1"
    
    # Fraud Detection
    MAX_CLICKS_PER_MINUTE_PER_IP = int(os.getenv("MAX_CLICKS_PER_MINUTE_PER_IP", "10"))
    MAX_CLICKS_PER_MINUTE_PER_IP_URL = int(os.getenv("MAX_CLICKS_PER_MINUTE_PER_IP_URL", "5"))
    VELOCITY_THRESHOLD = float(os.getenv("VELOCITY_THRESHOLD", "1.0"))
    MAX_CLICKS_PER_WINDOW = int(os.getenv("MAX_CLICKS_PER_WINDOW", "5"))
    WINDOW_SECONDS = int(os.getenv("WINDOW_SECONDS", "10"))
    MAX_SEQUENCE_LENGTH = int(os.getenv("MAX_SEQUENCE_LENGTH", "5"))
    
    # URL Settings
    SHORT_CODE_LENGTH = int(os.getenv("SHORT_CODE_LENGTH", "8"))
    MAX_URL_LENGTH = int(os.getenv("MAX_URL_LENGTH", "2048"))
    URL_EXPIRY_DAYS = int(os.getenv("URL_EXPIRY_DAYS", "0"))  # 0 = never expire
    
    # Cache Settings
    CACHE_DEFAULT_TIMEOUT = int(os.getenv("CACHE_DEFAULT_TIMEOUT", "86400"))  # 1 day
    CACHE_URL_TIMEOUT = int(os.getenv("CACHE_URL_TIMEOUT", "86400"))  # 1 day
    
    # Logging
    LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO")
    LOG_FORMAT = os.getenv("LOG_FORMAT", "json")  # json or text
    
    # CORS
    CORS_ORIGINS = os.getenv("CORS_ORIGINS", "*").split(",")
    
    # Monitoring
    PROMETHEUS_MULTIPROC_DIR = os.getenv("PROMETHEUS_MULTIPROC_DIR", "/tmp")
    ENABLE_METRICS = os.getenv("ENABLE_METRICS", "True").lower() == "true"
    
    # GeoIP
    GEOIP_DB_PATH = os.getenv("GEOIP_DB_PATH", "data/GeoLite2-City.mmdb")


class DevelopmentConfig(Config):
    """Development configuration"""
    DEBUG = True
    LOG_LEVEL = "DEBUG"


class TestingConfig(Config):
    """Testing configuration"""
    TESTING = True
    DEBUG = True
    
    # Use separate databases for testing
    DB_DATABASE = "urlshortener_test"
    REDIS_DB = 10
    
    # Shorter timeouts for tests
    JWT_ACCESS_TOKEN_EXPIRES = 60  # 1 minute
    JWT_REFRESH_TOKEN_EXPIRES = 300  # 5 minutes


class ProductionConfig(Config):
    """Production configuration"""
    DEBUG = False
    
    # Stricter settings for production
    RATE_LIMIT_PER_MINUTE = 30
    RATE_LIMIT_PER_HOUR = 500
    
    # Better pool settings
    DB_POOL_SIZE = 20
    REDIS_MAX_CONNECTIONS = 100
    
    # Ensure secret key is set
    SECRET_KEY = os.getenv("SECRET_KEY")
    if not SECRET_KEY or SECRET_KEY == "dev-secret-key-change-in-production":
        raise ValueError("SECRET_KEY must be set in production!")
    
    # Ensure JWT keys are properly configured
    if not os.path.exists(Config.JWT_PRIVATE_KEY_PATH):
        raise FileNotFoundError(f"JWT private key not found at {Config.JWT_PRIVATE_KEY_PATH}")
    if not os.path.exists(Config.JWT_PUBLIC_KEY_PATH):
        raise FileNotFoundError(f"JWT public key not found at {Config.JWT_PUBLIC_KEY_PATH}")


# Config dictionary
config = {
    "development": DevelopmentConfig,
    "testing": TestingConfig,
    "production": ProductionConfig,
    "default": DevelopmentConfig
}


def get_config(env: Optional[str] = None) -> Config:
    """Get configuration based on environment"""
    if env is None:
        env = os.getenv("FLASK_ENV", "development")
    
    return config.get(env, config["default"])()