fastapi/backend/app/config.py

#!/usr/bin/env python
"""
@Contact :   liuyuqi.gov@msn.cn
@Time    :   2024/03/22 08:06:24
@License :   Copyright © 2017-2022 liuyuqi. All Rights Reserved.
@Desc    :   global config
"""
import secrets
import warnings
from pathlib import Path
from typing import Annotated, Any, Literal

from pydantic import (AnyUrl, BaseModel, BeforeValidator, Field, HttpUrl,
                      PostgresDsn, computed_field, model_validator)
from pydantic_core import MultiHostUrl
from pydantic_settings import BaseSettings, SettingsConfigDict
from typing_extensions import Self


def parse_cors(v: Any) -> 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)


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file="../.env", env_ignore_empty=True, extra="ignore"
    )
    API_V1_STR: str = "/api/v1"
    SECRET_KEY: str = secrets.token_urlsafe(32)
    # 60 minutes * 24 hours * 8 days = 8 days
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24 * 8
    DOMAIN: str = "localhost"
    ENVIRONMENT: Literal["dev", "prod"] = "dev"

    @computed_field  # type: ignore[misc]
    @property
    def server_host(self) -> str:
        # Use HTTPS for anything other than local development
        if self.ENVIRONMENT == "local":
            return f"http://{self.DOMAIN}"
        return f"https://{self.DOMAIN}"

    BACKEND_CORS_ORIGINS: Annotated[
        list[AnyUrl] | str, BeforeValidator(parse_cors)
    ] = []

    PROJECT_NAME: str
    SENTRY_DSN: HttpUrl | None = None
    POSTGRES_SERVER: str
    POSTGRES_PORT: int = 5432
    POSTGRES_USER: str
    POSTGRES_PASSWORD: str
    POSTGRES_DB: str = ""

    @computed_field  # type: ignore[misc]
    @property
    def SQLALCHEMY_DATABASE_URI(self) -> PostgresDsn:
        return MultiHostUrl.build(
            scheme="postgresql+psycopg",
            username=self.POSTGRES_USER,
            password=self.POSTGRES_PASSWORD,
            host=self.POSTGRES_SERVER,
            port=self.POSTGRES_PORT,
            path=self.POSTGRES_DB,
        )

    SMTP_TLS: bool = True
    SMTP_SSL: bool = False
    SMTP_PORT: int = 587
    SMTP_HOST: str | None = None
    SMTP_USER: str | None = None
    SMTP_PASSWORD: str | None = None
    # TODO: update type to EmailStr when sqlmodel supports it
    EMAILS_FROM_EMAIL: str | None = None
    EMAILS_FROM_NAME: str | None = None

    @model_validator(mode="after")
    def _set_default_emails_from(self) -> Self:
        if not self.EMAILS_FROM_NAME:
            self.EMAILS_FROM_NAME = self.PROJECT_NAME
        return self

    EMAIL_RESET_TOKEN_EXPIRE_HOURS: int = 48

    @computed_field  # type: ignore[misc]
    @property
    def emails_enabled(self) -> bool:
        return bool(self.SMTP_HOST and self.EMAILS_FROM_EMAIL)

    # TODO: update type to EmailStr when sqlmodel supports it
    EMAIL_TEST_USER: str = "test@example.com"
    # TODO: update type to EmailStr when sqlmodel supports it
    FIRST_SUPERUSER: str
    FIRST_SUPERUSER_PASSWORD: str
    USERS_OPEN_REGISTRATION: bool = False

    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("POSTGRES_PASSWORD", self.POSTGRES_PASSWORD)
        self._check_default_secret(
            "FIRST_SUPERUSER_PASSWORD", self.FIRST_SUPERUSER_PASSWORD
        )

        return self

    # class Config:
    #     env_file = "../.env"
    #     from_attributes = True


class AppConfig(BaseModel):
    """ """

    BASE_DIR: Path = Path(__file__).resolve().parent.parent.parent
    SETTINGS_DIR: Path = BASE_DIR.joinpath("settings")
    SETTINGS_DIR.mkdir(parents=True, exist_ok=True)

    LOGS_DIR: Path = BASE_DIR.joinpath("logs")
    LOGS_DIR.mkdir(parents=True, exist_ok=True)

    MODELS_DIR: Path = BASE_DIR.joinpath("models")
    MODELS_DIR.mkdir(parents=True, exist_ok=True)

    # local cache directory to store images or text file
    CACHE_DIR: Path = BASE_DIR.joinpath("cache")
    CACHE_DIR.mkdir(parents=True, exist_ok=True)


class GlobalConfig(BaseSettings):
    # ENV_STATE: Optional[str] = Field(None, env="ENV_STATE")
    APP_CONFIG: AppConfig = AppConfig()

    API_NAME: str | None = Field(None, env="API_NAME")
    API_DESCRIPTION: str | None = Field(None, env="API_DESCRIPTION")
    API_VERSION: str | None = Field(None, env="API_VERSION")
    API_DEBUG_MODE: bool | None = Field(None, env="API_DEBUG_MODE")
    ENV_STATE: str | None = Field(None, env="ENV_STATE")
    LOG_CONFIG_FILENAME: str | None = Field(None, env="LOG_CONFIG_FILENAME")
    HOST: str | None = None
    PORT: int | None = None
    LOG_LEVEL: str | None = None

    DB: str | None = None

    MOBILENET_V2: str | None = None
    INCEPTION_V3: str | None = None

    class Setting:
        env_file: str = "../.env"
        from_attributes = True


class DevConfig(GlobalConfig):
    class Setting:
        env_prefix: str = "DEV_"


class ProdConfig(GlobalConfig):
    class Config:
        env_prefix: str = "PROD_"


class FactoryConfig:
    def __init__(self, env_state: str | None):
        self.env_state = env_state

    def __call__(self):
        if self.env_state == "dev":
            return DevConfig()
        elif self.env_state == "prod":
            return ProdConfig


settings = Settings()
# settings = FactoryConfig(GlobalConfig().ENV_STATE)()