import secrets

import warnings

from typing import Annotated, Any, Literal

from pydantic import (

    AnyUrl,

    BeforeValidator,

    EmailStr,

    HttpUrl,

    PostgresDsn,

    computed_field,

    model_validator,

)

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(",") if i.strip()]

    elif isinstance(v, list | str):

        return v

    raise ValueError(v)

class Settings(BaseSettings):

    model_config = SettingsConfigDict(

        # Use top level .env file (one level above ./backend/)

        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

    FRONTEND_HOST: str = "http://localhost:5173"

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

        list[AnyUrl] | str, BeforeValidator(parse_cors)

    ] = []

    @computed_field  # type: ignore[prop-decorator]

    @property

    def all_cors_origins(self) -> list[str]:

        return [str(origin).rstrip("/") for origin in self.BACKEND_CORS_ORIGINS] + [

            self.FRONTEND_HOST

        ]

    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[prop-decorator]

    @property

    def SQLALCHEMY_DATABASE_URI(self) -> PostgresDsn:

        return PostgresDsn.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

    EMAILS_FROM_EMAIL: EmailStr | 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[prop-decorator]

    @property

    def emails_enabled(self) -> bool:

        return bool(self.SMTP_HOST and self.EMAILS_FROM_EMAIL)

    EMAIL_TEST_USER: EmailStr = "test@example.com"

    FIRST_SUPERUSER: EmailStr

    FIRST_SUPERUSER_PASSWORD: str

    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

settings = Settings()  # type: ignore