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

import os
from pathlib import Path

SQL_DIR = Path(__file__).parent / "sql"


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

    Configure via DATABASE_URL (single connection string) or individual
    POSTGRES_* variables.
    """

    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")
    IMAGES_SCHEMA: str = os.getenv("IMAGES_SCHEMA", "raw_funda")
    IMAGES_TABLE: str = os.getenv("IMAGES_TABLE", "listing_details")

    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()


def load_sql(name: str) -> str:
    """Load a SQL template from the sql/ directory and inject schema/table names."""
    raw = (SQL_DIR / name).read_text()
    return raw.format(
        listings_schema=settings.LISTINGS_SCHEMA,
        listings_table=settings.LISTINGS_TABLE,
        elo_schema=settings.ELO_SCHEMA,
        images_schema=settings.IMAGES_SCHEMA,
        images_table=settings.IMAGES_TABLE,
    )