import os
from datetime import timedelta


class Config:
    """Base configuration"""

    SECRET_KEY = os.environ.get("SECRET_KEY") or "dev-secret-key-change-in-production"
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    JWT_SECRET_KEY = os.environ["JWT_SECRET_KEY"]
    JWT_ACCESS_TOKEN_EXPIRES = timedelta(hours=12)
    JWT_REFRESH_TOKEN_EXPIRES = timedelta(days=30)
    CORS_ORIGINS = os.environ.get("CORS_ORIGINS", "*")

    # Celery Configuration
    CELERY = {
        "broker_url": os.environ.get("CELERY_BROKER_URL", "redis://redis:6379/0"),
        "result_backend": os.environ.get(
            "CELERY_RESULT_BACKEND", "redis://redis:6379/0"
        ),
        "task_serializer": "json",
        "result_serializer": "json",
        "accept_content": ["json"],
        "timezone": "UTC",
        "enable_utc": True,
        "task_track_started": True,
        "task_time_limit": 30 * 60,  # 30 minutes
        "task_soft_time_limit": 25 * 60,  # 25 minutes
        "worker_prefetch_multiplier": 1,
        "worker_max_tasks_per_child": 100,
        "broker_connection_retry_on_startup": True,
    }

    SQLALCHEMY_ENGINE_OPTIONS = {
        "pool_size": 20,  # Reduce from default
        "max_overflow": 10,  # Reduce overflow
        "pool_timeout": 30,
        "pool_recycle": 1800,  # Recycle connections after 30 minutes
        "pool_pre_ping": True,  # Verify connections before using
    }


class DevelopmentConfig(Config):
    """Development configuration"""

    DEBUG = True
    SQLALCHEMY_DATABASE_URI = os.environ["DATABASE_URL"]


class TestingConfig(Config):
    """Testing configuration"""

    TESTING = True
    SQLALCHEMY_DATABASE_URI = os.environ.get("TEST_DATABASE_URL")
    WTF_CSRF_ENABLED = False

    # Conservative connection pool settings for testing
    SQLALCHEMY_ENGINE_OPTIONS = {
        "pool_size": 1,  # Only one connection in the pool
        "max_overflow": 0,  # No overflow connections allowed
        "pool_timeout": 30,
        "pool_recycle": 3600,  # Recycle after 1 hour
        "pool_pre_ping": True,  # Verify connections before using
    }


class ProductionConfig(Config):
    """Production configuration"""

    DEBUG = False
    SQLALCHEMY_DATABASE_URI = os.environ["DATABASE_URL"]

    # Security headers
    SESSION_COOKIE_SECURE = True
    SESSION_COOKIE_HTTPONLY = True
    SESSION_COOKIE_SAMESITE = "Lax"


config_by_name = {
    "dev": DevelopmentConfig,
    "test": TestingConfig,
    "prod": ProductionConfig,
}