from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path


@dataclass(frozen=True)
class Config:
    root_dir: Path
    port: int
    base_url: str
    database_path: Path
    employee_seed_path: Path
    workday_calendar_path: Path
    feishu_webhook_url: str
    feishu_webhook_secret: str
    feishu_app_id: str
    feishu_app_secret: str
    session_secret: str


def _read_dotenv(path: Path) -> dict[str, str]:
    if not path.exists():
        return {}

    values: dict[str, str] = {}
    for raw_line in path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        key, value = line.split("=", 1)
        values[key.strip()] = value.strip().strip('"').strip("'")
    return values


def read_config(env: dict[str, str] | None = None) -> Config:
    root_dir = Path(__file__).resolve().parent.parent
    dotenv_values = _read_dotenv(root_dir / ".env")
    values = {**dotenv_values, **dict(env if env is not None else os.environ)}
    port = int(values.get("PORT", "8787"))
    if port <= 0:
        raise ValueError("PORT must be a positive integer")

    return Config(
        root_dir=root_dir,
        port=port,
        base_url=values.get("BASE_URL", f"http://localhost:{port}"),
        database_path=(root_dir / values.get("DATABASE_PATH", "data/daily-report.sqlite")).resolve(),
        employee_seed_path=(root_dir / values.get("EMPLOYEE_SEED_PATH", "data/employees.json")).resolve(),
        workday_calendar_path=(root_dir / values.get("WORKDAY_CALENDAR_PATH", "data/workday-calendar.json")).resolve(),
        feishu_webhook_url=values.get("FEISHU_WEBHOOK_URL", ""),
        feishu_webhook_secret=values.get("FEISHU_WEBHOOK_SECRET", ""),
        feishu_app_id=values.get("FEISHU_APP_ID", ""),
        feishu_app_secret=values.get("FEISHU_APP_SECRET", ""),
        session_secret=values.get("SESSION_SECRET") or values.get("FEISHU_APP_SECRET") or "dev-session-secret",
    )