from pydantic import computed_field, model_validator
from pydantic_settings import BaseSettings, SettingsConfigDict
from typing import Literal, Self
import warnings


class Config(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env", env_ignore_empty=True, extra="ignore"
    )

    SECRET_KEY: str = "changethis"

    ENVIRONMENT: Literal["local", "staging", "production"] = "local"

    DB_NAME: str = "app"
    DB_HOST: str = "db"
    DB_PORT: int = 5432
    DB_USER: str = "app"
    DB_PASSWORD: str = "changethis"

    @computed_field
    @property
    def DATABASE_URI(self) -> str:
        return f"postgresql+asyncpg://{self.DB_USER}:{self.DB_PASSWORD}@{self.DB_HOST}:{self.DB_PORT}/{self.DB_NAME}"

    DOMAIN: str = "localhost"

    @computed_field
    @property
    def API_DOMAIN(self) -> str:
        if self.ENVIRONMENT == "local":
            return self.DOMAIN
        return f"api.{self.DOMAIN}"

    @computed_field
    @property
    def API_URL(self) -> str:
        if self.USE_NGROK:
            return self.NGROK_URL
        return (
            f"{'http' if self.ENVIRONMENT == 'local' else 'https'}://{self.API_DOMAIN}"
        )

    API_PORT: int = 8000

    TELEGRAM_BOT_TOKEN: str = "changethis"

    ADMIN_TELEGRAM_ID: int

    USE_NGROK: bool = False
    NGROK_AUTH_TOKEN: str = "changethis"
    NGROK_URL: str = ""

    LOG_LEVEL: str = "DEBUG"

    def _check_default_secret(self, var_name: str, value: str | None) -> None:
        if value == "changethis":
            message = (
                f'The value of {var_name} is "changethis", '
                "for security, please change it, at least for deployments."
            )
            if self.ENVIRONMENT == "local":
                warnings.warn(message, stacklevel=1)
            else:
                raise ValueError(message)

    @model_validator(mode="after")
    def _enforce_non_default_secrets(self) -> Self:
        self._check_default_secret("SECRET_KEY", self.SECRET_KEY)
        self._check_default_secret("DB_PASSWORD", self.DB_PASSWORD)
        self._check_default_secret("TELEGRAM_BOT_TOKEN", self.TELEGRAM_BOT_TOKEN)
        if self.USE_NGROK:
            self._check_default_secret("NGROK_AUTH_TOKEN", self.NGROK_AUTH_TOKEN)

        return self


config = Config()