"""Application configuration helpers."""

from __future__ import annotations

import os
from typing import Dict

from dotenv import load_dotenv

DEFAULT_IMMICH_URL = "https://photos.4angle.com/"
DEFAULT_OPENAI_MODEL = "gpt-4o-mini"


class ConfigError(RuntimeError):
    """Raised when critical configuration is missing."""


def load_settings() -> Dict[str, str]:
    """Load configuration from environment variables and ``api_keys``."""

    load_dotenv()

    db_path = os.getenv("STATION_DB", "")

    settings: Dict[str, str] = {
        "IMMICH_API_URL": os.getenv("IMMICH_API_URL", DEFAULT_IMMICH_URL).rstrip("/"),
        "IMMICH_API_KEY": os.getenv("IMMICH_API_KEY", ""),
        "OPENAI_API_KEY": os.getenv("OPENAI_API_KEY", ""),
        "RECENT_DAYS": int(os.getenv("RECENT_DAYS", "3")),
        "OPENAI_MODEL": os.getenv("OPENAI_MODEL", DEFAULT_OPENAI_MODEL),
        "STATION_DB": db_path,
        "SECRET_KEY": os.getenv("SECRET_KEY", ""),
        "MASTODON_BASE_URL": os.getenv(
            "MASTODON_BASE_URL", "http://localhost:3000"
        ).rstrip("/"),
        "MASTODON_ACCESS_TOKEN": os.getenv("MASTODON_ACCESS_TOKEN", ""),
        "MASTODON_CLIENT_KEY": os.getenv("MASTODON_CLIENT_KEY", ""),
        "MASTODON_CLIENT_SECRET": os.getenv("MASTODON_CLIENT_SECRET", ""),
    }

    missing = [
        key for key in ("IMMICH_API_KEY", "OPENAI_API_KEY") if not settings.get(key)
    ]
    if missing:
        raise ConfigError(
            "Missing required configuration values: " + ", ".join(missing)
        )

    return settings