import { MongoAPIError, ObjectId } from 'mongodb';
import bcrypt from 'bcrypt';
import { getCollections, update_pflux } from '../db/mongo.js';

export function registerApiRoutes(app, requireLogin) {
  const { usersCollection, propCollection } = getCollections();

  app.get('/api/check-email', async (req, res) => {
    const email = (req.query.email || '').toLowerCase().trim();
    if (!email) return res.json({ exists: false });
    try {
      const existingUser = await usersCollection.findOne({ email:`${email}` });
      res.json({ exists: !!existingUser });
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Fehler bei der E-Mail-Prüfung' });
    }
  });

  app.post('/api/save', requireLogin, async (req, res) => {
    let { espId, sensorNumber, name, description} = req.body;
    if (!espId || !sensorNumber) {
      return res.json({ error: 'ESP-ID und Sensornummer sind Pflichtfelder' });
    }
    sensorNumber = parseInt(sensorNumber, 10);
    try {
      const doc = {
        id: espId,
        name: name || '',
        description: description || '',
        lastUpdatedAt: new Date()
      };
      await update_pflux(sensorNumber, doc)
      res.json({ success: true });
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Fehler beim Speichern' });
    }
  });


  app.get('/api/list', requireLogin, async (req, res) => {
    const { id } = req.query;
    if (id) {
      try {
        const item = await propCollection.findOne({ _id: parseInt(id) });
        if (item) return res.json([item]);
        return res.json([]);
      } catch (err) {
        console.error(err);
        return res.status(500).json({ error: 'Fehler beim Laden' });
      }
    }

    let gesamtZahl = 0
    try {
        gesamtZahl = await propCollection.countDocuments({chip: {$exists: true}})
    } catch (err) {
      console.error(err);
    }
    const page = parseInt(req.query.page) || 1;
    const limit = parseInt(req.query.limit) || 50;
    const skip = (page - 1) * limit;
    try {
      const items = await propCollection.find({chip: {$exists: true}})
        .sort({ "chip.lastUpdatedAt": -1 })
        .skip(skip)
        .limit(limit)
        .toArray();
      const data = {items: items, anzahl: gesamtZahl}  
      res.json(data);
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Fehler beim Laden' });
    }
  });

  app.delete('/api/delete/:id', requireLogin, async (req, res) => {
    await propCollection.deleteOne({ _id: parseInt(req.params.id) });
    res.json({ success: true });
  });

  app.post('/api/createUser', requireLogin, async (req, res) => {
    if (!req.session.isAdmin) return res.status(403).json({ error: 'Nur Admins erlaubt' });
    const { username, password, role } = req.body;
    if (!username || !password) return res.status(400).json({ error: 'Benutzername und Passwort erforderlich' });
    try {
      const hash = await bcrypt.hash(password, 10);
      await usersCollection.insertOne({ email: username.toLowerCase(), passwordHash: hash, role: role || 'user' });
      res.json({ success: true });
    } catch (err) {
      res.status(500).json({ error: 'Fehler beim Anlegen' });
    }
  });

  app.post('/api/changePassword', requireLogin, async (req, res) => {
    const { currentPassword, newPassword } = req.body;
    if (!currentPassword || !newPassword) {
      return res.status(400).json({ error: 'Aktuelles und neues Passwort erforderlich' });
    }
    try {
      const user = await usersCollection.findOne({ _id: new ObjectId(req.session.userId) });
      if (!user) return res.status(404).json({ error: 'User nicht gefunden' });
      const match = await bcrypt.compare(currentPassword, user.passwordHash);
      if (!match) return res.status(403).json({ error: 'Aktuelles Passwort ist falsch' });
      const hash = await bcrypt.hash(newPassword, 10);
      await usersCollection.updateOne({ _id: user._id }, { $set: { passwordHash: hash } });
      res.json({ success: true });
    } catch (err) {
      res.status(500).json({ error: 'Fehler beim Ändern des Passworts' });
    }
  });

  app.post('/api/resetPassword', requireLogin, async (req, res) => {
    if (!req.session.isAdmin) return res.status(403).json({ error: 'Nur Admins erlaubt' });
    const { email, newPassword } = req.body;
    if (!email || !newPassword) return res.status(400).json({ error: 'Email und neues Passwort erforderlich' });
    try {
      const hash = await bcrypt.hash(newPassword, 10);
      const result = await usersCollection.updateOne(
        { email: email.toLowerCase() },
        { $set: { passwordHash: hash } }
      );
      if (result.matchedCount === 0) return res.status(404).json({ error: 'User nicht gefunden' });
      res.json({ success: true });
    } catch (err) {
      res.status(500).json({ error: 'Fehler beim Zurücksetzen' });
    }
  });

  app.get('/api/users', requireLogin, async (req, res) => {
    if (!req.session.isAdmin) return res.status(403).json({ error: 'Nur Admins erlaubt' });
    try {
      const users = await usersCollection.find({}, { projection: { email: 1, role: 1 } }).sort({ email: 1 }).toArray();
      res.json(users);
    } catch (err) {
      res.status(500).json({ error: 'Fehler beim Laden der User' });
    }
  });

  app.delete('/api/users/:id', requireLogin, async (req, res) => {
    if (!req.session.isAdmin) return res.status(403).json({ error: 'Nur Admins erlaubt' });
    const { id } = req.params;
    if (id === String(req.session.userId)) {
      return res.status(400).json({ error: 'Der eigene Account kann nicht gelöscht werden' });
    }
    try {
      const result = await usersCollection.deleteOne({ _id: new ObjectId(id) });
      if (result.deletedCount === 0) return res.status(404).json({ error: 'User nicht gefunden' });
      res.json({ success: true });
    } catch (err) {
      res.status(500).json({ error: 'Fehler beim Löschen' });
    }
  });
}