"""Application configuration from environment variables."""

import os


class Settings:
    """Application settings loaded from environment variables.

    Configure via DATABASE_URL (single connection string) or individual
    POSTGRES_* variables. The application expects the target database to
    contain:
      - A listings table (default: marts.funda_listings)
      - An ELO schema with ratings, comparisons, and sample_listings tables
        (default: elo.*)
    """

    POSTGRES_HOST: str = os.getenv("POSTGRES_HOST", "localhost")
    POSTGRES_PORT: int = int(os.getenv("POSTGRES_PORT", "5432"))
    POSTGRES_USER: str = os.getenv("POSTGRES_USER", "postgres")
    POSTGRES_PASSWORD: str = os.getenv("POSTGRES_PASSWORD", "postgres")
    POSTGRES_DB: str = os.getenv("POSTGRES_DB", "postgres")

    LISTINGS_SCHEMA: str = os.getenv("LISTINGS_SCHEMA", "marts")
    LISTINGS_TABLE: str = os.getenv("LISTINGS_TABLE", "funda_listings")
    ELO_SCHEMA: str = os.getenv("ELO_SCHEMA", "elo")

    K_FACTOR: float = float(os.getenv("ELO_K_FACTOR", "32"))
    DEFAULT_ELO: float = float(os.getenv("ELO_DEFAULT_RATING", "1500"))

    @property
    def database_url(self) -> str:
        url = os.getenv("DATABASE_URL")
        if url:
            return url
        return (
            f"postgresql+psycopg2://{self.POSTGRES_USER}:{self.POSTGRES_PASSWORD}"
            f"@{self.POSTGRES_HOST}:{self.POSTGRES_PORT}/{self.POSTGRES_DB}"
        )


settings = Settings()