from functools import lru_cache
from typing import Literal

from pydantic import AnyUrl, field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore",
    )

    # App
    APP_NAME: str = "Arkan API"
    ENV: Literal["development", "staging", "production"] = "development"
    DEBUG: bool = False

    # Security
    JWT_SECRET: str
    JWT_ALGORITHM: str = "HS256"
    JWT_EXPIRE_MINUTES: int = 60 * 24  # 24h

    # Admin seed
    ADMIN_USERNAME: str
    ADMIN_PASSWORD: str

    # Database
    DATABASE_URL: str  # sync (for Alembic)
    ASYNC_DATABASE_URL: str = ""

    

    @field_validator("ASYNC_DATABASE_URL", mode="before")
    @classmethod
    def build_async_url(cls, v: str, info) -> str:
        if v:
            return v
        sync = info.data.get("DATABASE_URL", "")
        return sync.replace("postgresql://", "postgresql+asyncpg://", 1)

    # Redis
    REDIS_URL: str = "redis://localhost:6379/0"

    # CORS
    ALLOWED_ORIGINS: str = "http://localhost:3000"

    @property
    def allowed_origins_list(self) -> list[str]:
        return [o.strip() for o in self.ALLOWED_ORIGINS.split(",")]

    # Rate limiting
    RATE_LIMIT_DEFAULT: str = "100/minute"
    RATE_LIMIT_AUTH: str = "10/minute"       # تقييد أشد على تسجيل الدخول

    # DB pool
    DB_POOL_SIZE: int = 10
    DB_MAX_OVERFLOW: int = 20


@lru_cache
def get_settings() -> Settings:
    return Settings()

settings = get_settings()