from typing import Any, Dict, Optional
from pydantic import BaseSettings, PostgresDsn, HttpUrl, validator

class Settings(BaseSettings):
    API_V1_STR: str = "/api/v1"
    POSTGRES_SERVER: str
    POSTGRES_USER: str
    POSTGRES_PASSWORD: str
    POSTGRES_DB: str
    LABEL_STUDIO_URL: str
    LABEL_STUDIO_API_KEY: str
    LABEL_STUDIO_PROJECT_ID: str
    PROJECT_NAME: Optional[str] = "LangChain"
    DESCRIPTION: Optional[str] = "LLM chain"
    SQLALCHEMY_DATABASE_URI: Optional[PostgresDsn] = None
    SENTRY_DSN: Optional[HttpUrl] = None

    @validator("SENTRY_DSN", pre=True)
    def sentry_dsn_can_be_blank(cls, v: str) -> Optional[str]:
        if len(v) == 0:
            return None
        return v

    @validator("SQLALCHEMY_DATABASE_URI", 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 ''}",
        )

    class Config:
        case_sensitive = True


settings = Settings()