"""
Application configuration using Pydantic settings.
Supports environment variables and .env files.
"""
from typing import Optional, List
from pydantic_settings import BaseSettings, SettingsConfigDict
from pydantic import PostgresDsn, field_validator, ValidationInfo


class Settings(BaseSettings):
    """Application settings loaded from environment variables"""
    
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore"
    )
    
    # Application
    APP_NAME: str = "POP3 Forwarder SaaS"
    APP_VERSION: str = "2.0.0"
    DEBUG: bool = False
    API_V1_PREFIX: str = "/api/v1"
    
    # Server
    HOST: str = "0.0.0.0"
    PORT: int = 8000
    
    # Database
    DATABASE_URL: str = "postgresql+asyncpg://user:password@localhost:5432/pop3_forwarder"
    DATABASE_POOL_SIZE: int = 20
    DATABASE_MAX_OVERFLOW: int = 10
    
    # Security
    SECRET_KEY: str = "change-this-to-a-secure-random-secret-key-in-production"
    ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
    REFRESH_TOKEN_EXPIRE_DAYS: int = 7
    
    # Encryption (for storing POP3/IMAP credentials)
    ENCRYPTION_KEY: str = "change-this-to-a-secure-encryption-key"
    
    # OAuth2 - Google
    GOOGLE_CLIENT_ID: Optional[str] = None
    GOOGLE_CLIENT_SECRET: Optional[str] = None
    GOOGLE_REDIRECT_URI: str = "http://localhost:3000/auth/callback/google"
    
    # CORS
    CORS_ORIGINS: List[str] = ["http://localhost:3000", "http://localhost:8000"]
    
    # Stripe Payment
    STRIPE_API_KEY: Optional[str] = None
    STRIPE_WEBHOOK_SECRET: Optional[str] = None
    STRIPE_PUBLISHABLE_KEY: Optional[str] = None
    
    # Subscription Tiers
    TIER_FREE_MAX_ACCOUNTS: int = 1
    TIER_BASIC_MAX_ACCOUNTS: int = 5
    TIER_PRO_MAX_ACCOUNTS: int = 20
    TIER_ENTERPRISE_MAX_ACCOUNTS: int = 100
    
    # Email Processing
    MAX_EMAILS_PER_RUN: int = 50
    CHECK_INTERVAL_MINUTES: int = 5
    THROTTLE_EMAILS_PER_MINUTE: int = 10
    
    # Redis (for Celery and caching)
    REDIS_URL: str = "redis://localhost:6379/0"
    
    # Celery
    CELERY_BROKER_URL: str = "redis://localhost:6379/0"
    CELERY_RESULT_BACKEND: str = "redis://localhost:6379/0"
    
    # Apprise (notifications)
    APPRISE_ENABLED: bool = True
    
    # Logging
    LOG_LEVEL: str = "INFO"
    
    # Admin
    ADMIN_EMAIL: Optional[str] = None
    ADMIN_PASSWORD: Optional[str] = None
    
    # Mail Server Presets
    MAIL_SERVER_PRESETS_FILE: str = "app/data/mail_server_presets.json"
    
    @field_validator("CORS_ORIGINS", mode="before")
    @classmethod
    def assemble_cors_origins(cls, v: str | List[str]) -> List[str]:
        """Parse CORS origins from environment variable"""
        if isinstance(v, str):
            return [i.strip() for i in v.split(",")]
        return v


# Global settings instance
settings = Settings()