course_catcher/config.py

from __future__ import annotations

import hashlib
import os
from dataclasses import dataclass
from pathlib import Path


def _default_data_dir() -> Path:
    persistent_root = Path("/data")
    if persistent_root.exists():
        return persistent_root / "scu-course-catcher"
    return Path("runtime")


@dataclass(frozen=True)
class AppConfig:
    admin_username: str
    admin_password: str
    secret_key: str
    data_dir: Path
    database_path: Path
    chrome_binary: str
    chromedriver_binary: str
    default_parallelism: int
    loop_interval_seconds: float
    login_retry_limit: int
    request_timeout_seconds: int
    debug: bool


def load_config() -> AppConfig:
    admin_username = os.getenv("ADMIN", "admin")
    admin_password = os.getenv("PASSWORD", "change-me-now")

    derived_secret = hashlib.sha256(
        f"{admin_username}:{admin_password}:scu-course-catcher".encode("utf-8")
    ).hexdigest()
    secret_key = os.getenv("APP_SECRET", derived_secret)

    data_dir = Path(os.getenv("APP_DATA_DIR", str(_default_data_dir()))).resolve()
    data_dir.mkdir(parents=True, exist_ok=True)

    return AppConfig(
        admin_username=admin_username,
        admin_password=admin_password,
        secret_key=secret_key,
        data_dir=data_dir,
        database_path=data_dir / "app.db",
        chrome_binary=os.getenv("CHROME_BIN", "/usr/bin/chromium"),
        chromedriver_binary=os.getenv("CHROMEDRIVER_BIN", "/usr/bin/chromedriver"),
        default_parallelism=max(1, int(os.getenv("DEFAULT_PARALLELISM", "1"))),
        loop_interval_seconds=max(1.0, float(os.getenv("LOOP_INTERVAL_SECONDS", "3"))),
        login_retry_limit=max(1, int(os.getenv("LOGIN_RETRY_LIMIT", "6"))),
        request_timeout_seconds=max(15, int(os.getenv("REQUEST_TIMEOUT_SECONDS", "30"))),
        debug=os.getenv("DEBUG", "").lower() in {"1", "true", "yes", "on"},
    )