const express = require("express");
const bcrypt = require("bcryptjs");
const jwt = require("jsonwebtoken");
const db = require("./db");
require("dotenv").config();

const app = express();
app.use(express.json());

// Simple CORS middleware for browser-based admin UI testing.
app.use((req, res, next) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS");
  res.setHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");
  if (req.method === "OPTIONS") {
    return res.sendStatus(204);
  }
  next();
});

const ERROR_LOG_API_URL =
  process.env.ERROR_LOG_API_URL ||
  "https://error.xtransit.testinstance.nl/error_log";

function friendlyErrorMessage(statusCode) {
  if (statusCode === 400) return "Controleer je invoer en probeer opnieuw.";
  if (statusCode === 401) return "Je sessie is verlopen. Log opnieuw in.";
  if (statusCode === 403) return "Je hebt hier geen toegang toe.";
  if (statusCode === 404) return "Niet gevonden.";
  return "Er ging iets mis. Probeer het later opnieuw.";
}

async function reportError({ partofservice, error }) {
  try {
    await fetch(ERROR_LOG_API_URL, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        service: "auth_api",
        partofservice,
        error,
      }),
    });
  } catch (_) {}
}

app.use((req, res, next) => {
  const originalJson = res.json.bind(res);
  res.json = (body) => {
    if (res.statusCode >= 400 && body && typeof body === "object") {
      const rawError =
        body.error || body.message || body.details || `HTTP ${res.statusCode}`;
      void reportError({
        partofservice: `${req.method} ${req.originalUrl}`,
        error: rawError,
      });
      return originalJson({ error: friendlyErrorMessage(res.statusCode) });
    }
    return originalJson(body);
  };

  next();
});

const JWT_SECRET = process.env.JWT_SECRET;
const ADMIN_USER_CODES = new Set(
  String(process.env.ADMIN_USER_CODES || "")
    .split(",")
    .map((c) => Number(c.trim()))
    .filter(Number.isFinite),
);

app.post("/login", async (req, res) => {
  try {
    const { userCode, password } = req.body;
    if (!userCode || !password)
      return res.status(400).json({ error: "userCode and password required" });

    const result = await db.query(
      "SELECT id, usercode, password FROM workers.users WHERE usercode = $1",
      [userCode],
    );
    const user = result.rows[0];
    if (!user) return res.status(401).json({ error: "invalid_credentials" });

    const ok = await bcrypt.compare(password, user.password);
    if (!ok) return res.status(401).json({ error: "invalid_credentials" });

    const isAdmin = ADMIN_USER_CODES.has(Number(user.usercode));
    const payload = { userId: user.id, userCode: user.usercode, isAdmin };
    const token = jwt.sign(payload, JWT_SECRET, { expiresIn: "1h" });

    res.json({
      token,
      user: { id: user.id, userCode: user.usercode, job: user.job, isAdmin },
    });
  } catch (err) {
    await reportError({
      partofservice: `${req.method} ${req.originalUrl}`,
      error: err?.stack || err?.message || String(err),
    });
    console.error(err);
    res.status(500).json({ error: friendlyErrorMessage(500) });
  }
});

app.get("/me", async (req, res) => {
  const auth = req.headers.authorization;
  if (!auth || !auth.startsWith("Bearer "))
    return res.status(401).json({ error: "missing_token" });
  const token = auth.slice(7);
  try {
    const payload = jwt.verify(token, JWT_SECRET);
    res.json({ user: payload });
  } catch (err) {
    void reportError({
      partofservice: `${req.method} ${req.originalUrl}`,
      error: err?.stack || err?.message || String(err),
    });
    res.status(401).json({ error: friendlyErrorMessage(401) });
  }
});

// Development helper removed for production safety.
// The /dev/token endpoint was intentionally removed to prevent accidental
// issuance of tokens in production builds. Use the real authentication flow
// (POST /login) or re-enable this code only in local development branches.

const PORT = process.env.PORT || 5000;
app.listen(PORT, () => console.log(`Auth API listening on ${PORT}`));

module.exports = app;