const express = require('express');
const { sha256, safeEqual } = require('../utils/hash');
const storage = require('../utils/storage');
const { requireAdmin } = require('../auth');
const { generateBookPdf } = require('../pdf');

const router = express.Router();

const ADMIN_PASSWORD_HASH = (process.env.ADMIN_PASSWORD_HASH || '').trim().toLowerCase();

// --- Admin Login ---
router.post('/login', (req, res) => {
  const { password } = req.body || {};
  if (!password || !ADMIN_PASSWORD_HASH) {
    return res.status(400).json({ error: 'Passwort erforderlich.' });
  }
  const hash = sha256(password);
  if (!safeEqual(hash, ADMIN_PASSWORD_HASH)) {
    return res.status(401).json({ error: 'Falsches Passwort.' });
  }
  req.session.role = 'admin';
  req.session.friendId = null;
  return res.json({ ok: true });
});

router.post('/logout', (req, res) => {
  req.session = null;
  res.json({ ok: true });
});

router.get('/session', (req, res) => {
  if (req.session && req.session.role) {
    return res.json({ role: req.session.role, friendId: req.session.friendId || null });
  }
  res.json({ role: null });
});

// --- Freunde-Verwaltung (nur Admin) ---
router.get('/friends', requireAdmin, (req, res) => {
  const friends = storage.getAllFriendsMeta().map((f) => ({
    id: f.id,
    folderName: f.folderName,
    name: f.name,
    createdAt: f.createdAt,
    profileImage: f.profileImage,
    shareEnabled: !!(f.share && f.share.enabled),
    blockCount: (f.blocks || []).length,
  }));
  res.json({ friends });
});

router.post('/friends', requireAdmin, (req, res) => {
  const { name } = req.body || {};
  if (!name || !String(name).trim()) {
    return res.status(400).json({ error: 'Name erforderlich.' });
  }
  const meta = storage.createFriend(String(name).trim());
  res.json({ friend: meta });
});

router.delete('/friends/:id', requireAdmin, (req, res) => {
  const folder = storage.findFolderById(req.params.id);
  if (!folder) return res.status(404).json({ error: 'Nicht gefunden.' });
  storage.deleteFriend(folder);
  res.json({ ok: true });
});

// Freigabe (Share-Link) verwalten
router.post('/friends/:id/share', requireAdmin, (req, res) => {
  const folder = storage.findFolderById(req.params.id);
  if (!folder) return res.status(404).json({ error: 'Nicht gefunden.' });
  const meta = storage.readMeta(folder);
  const { enabled, password } = req.body || {};

  if (enabled === false) {
    meta.share.enabled = false;
    storage.writeMeta(folder, meta);
    return res.json({ friend: meta });
  }

  if (!password || String(password).length < 4) {
    return res.status(400).json({ error: 'Bitte ein Passwort mit mindestens 4 Zeichen vergeben.' });
  }
  meta.share.enabled = true;
  meta.share.passwordHash = sha256(password);
  storage.writeMeta(folder, meta);
  res.json({ friend: meta });
});

// --- Freundesbuch-Ansicht (aggregiert, nur Admin) ---
router.get('/book', requireAdmin, (req, res) => {
  const friends = storage.getAllFriendsMeta().map((f) => ({
    ...f,
    share: { enabled: !!(f.share && f.share.enabled) }, // Passwort-Hash nie an den Client senden
  }));
  res.json({ friends });
});

router.get('/book/pdf', requireAdmin, async (req, res) => {
  try {
    const pdfBuffer = await generateBookPdf();
    res.setHeader('Content-Type', 'application/pdf');
    res.setHeader('Content-Disposition', 'attachment; filename="freundesbuch.pdf"');
    res.send(pdfBuffer);
  } catch (err) {
    console.error('PDF-Export fehlgeschlagen:', err);
    res.status(500).json({ error: 'PDF-Export fehlgeschlagen.' });
  }
});

module.exports = router;