from pathlib import Path

from pydantic_settings import BaseSettings, SettingsConfigDict

_PROJECT_ROOT = Path(__file__).parent.parent.parent


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        extra="ignore",
    )

    # PostgreSQL (local dev)
    postgres_user: str = "olist"
    postgres_password: str = "olist_secret"
    postgres_db: str = "olist_dw"
    postgres_host: str = "localhost"
    postgres_port: int = 5432
    database_url: str = str(_PROJECT_ROOT / "data" / "olist.db")

    # MLflow (local dev / training only)
    mlflow_tracking_uri: str = "http://localhost:5000"

    # FastAPI
    fastapi_url: str = "http://localhost:8000"

    # Data paths — override via DATA_DIR / RAW_DATA_DIR env vars in containers
    data_dir: Path = _PROJECT_ROOT / "data"
    raw_data_dir: Path = _PROJECT_ROOT / "data" / "raw"

    # ML model paths (used instead of MLflow in deployed environments)
    churn_model_path: str = str(_PROJECT_ROOT / "models" / "churn_model.joblib")
    segmentation_model_path: str = str(_PROJECT_ROOT / "models" / "segmentation_pipeline.joblib")

    @property
    def processed_data_dir(self) -> Path:
        return self.data_dir / "processed"

    @property
    def sync_database_url(self) -> str:
        """psycopg2-compatible URL for Alembic / Airflow."""
        return self.database_url.replace("postgresql+psycopg://", "postgresql+psycopg2://")

    @property
    def sqlalchemy_database_url(self) -> str:
        """Return a SQLAlchemy-compatible URL, adding sqlite:/// prefix if needed."""
        url = self.database_url
        if not url.startswith(("sqlite", "postgresql", "mysql", "mssql")):
            return f"sqlite:///{url}"
        return url


settings = Settings()