import secrets
from pathlib import Path
from typing import Literal

from loguru import logger
from passlib.context import CryptContext
from pydantic import Field, SecretStr, field_validator
from pydantic_settings import BaseSettings

from langflow.services.settings.constants import DEFAULT_SUPERUSER, DEFAULT_SUPERUSER_PASSWORD
from langflow.services.settings.utils import read_secret_from_file, write_secret_to_file


class AuthSettings(BaseSettings):
    # Login settings
    CONFIG_DIR: str
    SECRET_KEY: SecretStr = Field(
        default=SecretStr(""),
        description="Secret key for JWT. If not provided, a random one will be generated.",
        frozen=False,
    )
    ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_SECONDS: int = 60 * 60  # 1 hour
    REFRESH_TOKEN_EXPIRE_SECONDS: int = 60 * 60 * 24 * 7  # 7 days

    # API Key to execute /process endpoint
    API_KEY_ALGORITHM: str = "HS256"
    API_V1_STR: str = "/api/v1"

    # If AUTO_LOGIN = True
    # > The application does not request login and logs in automatically as a super user.
    AUTO_LOGIN: bool = True
    NEW_USER_IS_ACTIVE: bool = False
    SUPERUSER: str = DEFAULT_SUPERUSER
    SUPERUSER_PASSWORD: str = DEFAULT_SUPERUSER_PASSWORD

    REFRESH_SAME_SITE: Literal["lax", "strict", "none"] = "none"
    """The SameSite attribute of the refresh token cookie."""
    REFRESH_SECURE: bool = True
    """The Secure attribute of the refresh token cookie."""
    REFRESH_HTTPONLY: bool = True
    """The HttpOnly attribute of the refresh token cookie."""
    ACCESS_SAME_SITE: Literal["lax", "strict", "none"] = "lax"
    """The SameSite attribute of the access token cookie."""
    ACCESS_SECURE: bool = False
    """The Secure attribute of the access token cookie."""
    ACCESS_HTTPONLY: bool = False
    """The HttpOnly attribute of the access token cookie."""

    COOKIE_DOMAIN: str | None = None
    """The domain attribute of the cookies. If None, the domain is not set."""

    pwd_context: CryptContext = CryptContext(schemes=["bcrypt"], deprecated="auto")

    class Config:
        validate_assignment = True
        extra = "ignore"
        env_prefix = "LANGFLOW_"

    def reset_credentials(self) -> None:
        self.SUPERUSER = DEFAULT_SUPERUSER
        self.SUPERUSER_PASSWORD = DEFAULT_SUPERUSER_PASSWORD

    # If autologin is true, then we need to set the credentials to
    # the default values
    # so we need to validate the superuser and superuser_password
    # fields
    @field_validator("SUPERUSER", "SUPERUSER_PASSWORD", mode="before")
    @classmethod
    def validate_superuser(cls, value, info):
        if info.data.get("AUTO_LOGIN"):
            if value != DEFAULT_SUPERUSER:
                value = DEFAULT_SUPERUSER
                logger.debug("Resetting superuser to default value")
            if info.data.get("SUPERUSER_PASSWORD") != DEFAULT_SUPERUSER_PASSWORD:
                info.data["SUPERUSER_PASSWORD"] = DEFAULT_SUPERUSER_PASSWORD
                logger.debug("Resetting superuser password to default value")

            return value

        return value

    @field_validator("SECRET_KEY", mode="before")
    @classmethod
    def get_secret_key(cls, value, info):
        config_dir = info.data.get("CONFIG_DIR")

        if not config_dir:
            logger.debug("No CONFIG_DIR provided, not saving secret key")
            return value or secrets.token_urlsafe(32)

        secret_key_path = Path(config_dir) / "secret_key"

        if value:
            logger.debug("Secret key provided")
            secret_value = value.get_secret_value() if isinstance(value, SecretStr) else value
            write_secret_to_file(secret_key_path, secret_value)
        else:
            logger.debug("No secret key provided, generating a random one")

            if secret_key_path.exists():
                value = read_secret_from_file(secret_key_path)
                logger.debug("Loaded secret key")
                if not value:
                    value = secrets.token_urlsafe(32)
                    write_secret_to_file(secret_key_path, value)
                    logger.debug("Saved secret key")
            else:
                value = secrets.token_urlsafe(32)
                write_secret_to_file(secret_key_path, value)
                logger.debug("Saved secret key")

        return value if isinstance(value, SecretStr) else SecretStr(value).get_secret_value()