import secrets
from typing import Any, Dict, List, Optional, Union

from pydantic import AnyHttpUrl, BaseSettings, PostgresDsn, validator


class Settings(BaseSettings):
    API_PREFIX: str = "/api"
    SECRET_KEY: str = secrets.token_urlsafe(32)
    # 60 minutes * 24 hours * 8 days = 8 days
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24 * 8
    # BACKEND_CORS_ORIGINS is a JSON-formatted list of origins
    # e.g: '["http://localhost", "http://localhost:4200", "http://localhost:3000"]'
    BACKEND_CORS_ORIGINS: List[AnyHttpUrl] = []

    @validator("BACKEND_CORS_ORIGINS", pre=True)
    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], str]:
        if isinstance(v, str) and not v.startswith("["):
            return [i.strip() for i in v.split(",")]
        elif isinstance(v, (list, str)):
            return v
        raise ValueError(v)

    PROJECT_NAME: str
    
    POSTGRES_SERVER: str
    POSTGRES_USER: str
    POSTGRES_PASSWORD: str
    POSTGRES_DB: str
    DATABASE_URL: Optional[PostgresDsn] = None

    @validator("DATABASE_URL", pre=True)
    def assemble_db_connection(cls, v: Optional[str], values: Dict[str, Any]) -> Any:
        if isinstance(v, str):
            return v
        return PostgresDsn.build(
            scheme="postgresql",
            user=values.get("POSTGRES_USER"),
            password=values.get("POSTGRES_PASSWORD"),
            host=values.get("POSTGRES_SERVER"),
            path=f"/{values.get('POSTGRES_DB') or ''}",
        )

    REDIS_HOST: str
    REDIS_PORT: int
    
    JWT_SECRET_KEY: str
    JWT_ALGORITHM: str = "HS256"

    class Config:
        case_sensitive = True
        env_file = ".env"


settings = Settings()