import { Router, Request, Response } from 'express';
import { v4 as uuidv4 } from 'uuid';
import crypto from 'crypto';
import multer, { FileFilterCallback } from 'multer';
import path from 'path';
import fs from 'fs';
import { fileURLToPath } from 'url';
import { userOps, questionnaireOps, activityOps, participantOps } from '../database.js';
import { requireAuth } from '../middleware/auth.js';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Configure multer for image uploads
const uploadsDir = process.env.NODE_ENV === 'production' 
  ? '/app/data/uploads'
  : path.join(__dirname, '..', '..', 'data', 'uploads');

// Ensure uploads directory exists
if (!fs.existsSync(uploadsDir)) {
  fs.mkdirSync(uploadsDir, { recursive: true });
}

const storage = multer.diskStorage({
  destination: (_req: Request, _file: Express.Multer.File, cb: (error: Error | null, destination: string) => void) => {
    cb(null, uploadsDir);
  },
  filename: (_req: Request, file: Express.Multer.File, cb: (error: Error | null, filename: string) => void) => {
    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
    const ext = path.extname(file.originalname);
    cb(null, 'og-' + uniqueSuffix + ext);
  }
});

const upload = multer({
  storage,
  limits: { fileSize: 5 * 1024 * 1024 }, // 5MB max
  fileFilter: (_req: Request, file: Express.Multer.File, cb: FileFilterCallback) => {
    const allowedTypes = ['image/jpeg', 'image/png', 'image/gif', 'image/webp'];
    if (allowedTypes.includes(file.mimetype)) {
      cb(null, true);
    } else {
      cb(new Error('Alleen JPEG, PNG, GIF en WebP afbeeldingen zijn toegestaan'));
    }
  }
});

const router = Router();

// Apply auth middleware to all admin routes
router.use(requireAuth);

// Upload image
router.post('/upload', upload.single('image'), (req: Request, res: Response) => {
  const file = req.file as Express.Multer.File | undefined;
  if (!file) {
    res.status(400).json({ error: 'Geen bestand geüpload' });
    return;
  }
  
  // Return the URL to access the uploaded file
  const imageUrl = `/uploads/${file.filename}`;
  res.json({ success: true, url: imageUrl });
});

// Get all questionnaires
router.get('/questionnaires', (_req: Request, res: Response) => {
  const questionnaires = questionnaireOps.getAll();
  res.json(questionnaires);
});

// Validate slug format
function isValidSlug(slug: string): boolean {
  return /^[a-z0-9]+(?:-[a-z0-9]+)*$/.test(slug);
}

// Create questionnaire
router.post('/questionnaires', (req: Request, res: Response) => {
  const { title, description, slug, ogImage, isPrivate } = req.body;
  
  if (!title?.trim()) {
    res.status(400).json({ error: 'Titel is verplicht' });
    return;
  }
  
  if (!slug?.trim()) {
    res.status(400).json({ error: 'Slug is verplicht' });
    return;
  }
  
  const cleanSlug = slug.trim().toLowerCase();
  
  if (!isValidSlug(cleanSlug)) {
    res.status(400).json({ error: 'Slug mag alleen kleine letters, cijfers en koppeltekens bevatten' });
    return;
  }
  
  if (cleanSlug.length < 3 || cleanSlug.length > 50) {
    res.status(400).json({ error: 'Slug moet tussen 3 en 50 tekens zijn' });
    return;
  }
  
  if (!questionnaireOps.isSlugAvailable(cleanSlug)) {
    res.status(400).json({ error: 'Deze slug is al in gebruik' });
    return;
  }
  
  const uuid = uuidv4();
  const id = questionnaireOps.create(uuid, cleanSlug, title.trim(), description?.trim() || null, ogImage?.trim() || null, !!isPrivate, req.session.user!.id);
  const questionnaire = questionnaireOps.findById(id);
  
  res.json({ success: true, questionnaire });
});

// Get questionnaire by ID
router.get('/questionnaires/:id', (req: Request, res: Response) => {
  const questionnaire = questionnaireOps.findById(parseInt(req.params.id));
  
  if (!questionnaire) {
    res.status(404).json({ error: 'Vragenlijst niet gevonden' });
    return;
  }
  
  const activities = activityOps.getByQuestionnaire(questionnaire.id);
  res.json({ questionnaire, activities });
});

// Update questionnaire
router.put('/questionnaires/:id', (req: Request, res: Response) => {
  const { title, description, slug, ogImage, isPrivate } = req.body;
  const questionnaire = questionnaireOps.findById(parseInt(req.params.id));
  
  if (!questionnaire) {
    res.status(404).json({ error: 'Vragenlijst niet gevonden' });
    return;
  }
  
  if (!title?.trim()) {
    res.status(400).json({ error: 'Titel is verplicht' });
    return;
  }
  
  if (!slug?.trim()) {
    res.status(400).json({ error: 'Slug is verplicht' });
    return;
  }
  
  const cleanSlug = slug.trim().toLowerCase();
  
  if (!isValidSlug(cleanSlug)) {
    res.status(400).json({ error: 'Slug mag alleen kleine letters, cijfers en koppeltekens bevatten' });
    return;
  }
  
  if (cleanSlug.length < 3 || cleanSlug.length > 50) {
    res.status(400).json({ error: 'Slug moet tussen 3 en 50 tekens zijn' });
    return;
  }
  
  if (!questionnaireOps.isSlugAvailable(cleanSlug, questionnaire.id)) {
    res.status(400).json({ error: 'Deze slug is al in gebruik' });
    return;
  }
  
  questionnaireOps.update(questionnaire.id, cleanSlug, title.trim(), description?.trim() || null, ogImage?.trim() || null, !!isPrivate);
  res.json({ success: true });
});

// Check slug availability
router.get('/questionnaires/check-slug/:slug', (req: Request, res: Response) => {
  const { slug } = req.params;
  const { excludeId } = req.query;
  
  const cleanSlug = slug.trim().toLowerCase();
  const available = questionnaireOps.isSlugAvailable(cleanSlug, excludeId ? parseInt(excludeId as string) : undefined);
  
  res.json({ available });
});

// Get participants for a questionnaire
router.get('/questionnaires/:id/participants', (req: Request, res: Response) => {
  const questionnaire = questionnaireOps.findById(parseInt(req.params.id));
  
  if (!questionnaire) {
    res.status(404).json({ error: 'Vragenlijst niet gevonden' });
    return;
  }
  
  const participants = participantOps.getByQuestionnaire(questionnaire.id);
  res.json(participants);
});

// Generate unique token
function generateToken(): string {
  return crypto.randomBytes(16).toString('hex');
}

// Add participant to questionnaire
router.post('/questionnaires/:id/participants', (req: Request, res: Response) => {
  const { name } = req.body;
  const questionnaire = questionnaireOps.findById(parseInt(req.params.id));
  
  if (!questionnaire) {
    res.status(404).json({ error: 'Vragenlijst niet gevonden' });
    return;
  }
  
  if (!name?.trim()) {
    res.status(400).json({ error: 'Naam is verplicht' });
    return;
  }
  
  // Generate unique token
  let token = generateToken();
  while (!participantOps.isTokenAvailable(token)) {
    token = generateToken();
  }
  
  const id = participantOps.create(questionnaire.id, name.trim(), token);
  const participant = participantOps.findById(id);
  
  res.json({ success: true, participant });
});

// Delete participant
router.delete('/participants/:id', (req: Request, res: Response) => {
  participantOps.delete(parseInt(req.params.id));
  res.json({ success: true });
});

// Delete questionnaire
router.delete('/questionnaires/:id', (req: Request, res: Response) => {
  questionnaireOps.delete(parseInt(req.params.id));
  res.json({ success: true });
});

// Update activity
router.put('/activities/:id', (req: Request, res: Response) => {
  const { name, description } = req.body;
  const activity = activityOps.findById(parseInt(req.params.id));
  
  if (!activity) {
    res.status(404).json({ error: 'Activiteit niet gevonden' });
    return;
  }
  
  if (!name?.trim()) {
    res.status(400).json({ error: 'Naam activiteit is verplicht' });
    return;
  }
  
  activityOps.update(activity.id, name.trim(), description?.trim() || null);
  const updatedActivity = activityOps.findById(activity.id);
  res.json({ success: true, activity: updatedActivity });
});

// Delete activity
router.delete('/activities/:id', (req: Request, res: Response) => {
  activityOps.delete(parseInt(req.params.id));
  res.json({ success: true });
});

// Get all users
router.get('/users', (_req: Request, res: Response) => {
  const users = userOps.getAll();
  res.json(users);
});

// Create user
router.post('/users', (req: Request, res: Response) => {
  const { username, password } = req.body;
  
  if (!username || !password) {
    res.status(400).json({ error: 'Gebruikersnaam en wachtwoord zijn verplicht' });
    return;
  }
  
  if (password.length < 6) {
    res.status(400).json({ error: 'Wachtwoord moet minimaal 6 tekens zijn' });
    return;
  }
  
  const existingUser = userOps.findByUsername(username);
  if (existingUser) {
    res.status(400).json({ error: 'Gebruikersnaam bestaat al' });
    return;
  }
  
  const id = userOps.create(username, password);
  const user = userOps.findById(id);
  res.json({ success: true, user });
});

// Delete user
router.delete('/users/:id', (req: Request, res: Response) => {
  const userId = parseInt(req.params.id);
  
  if (userId === req.session.user!.id) {
    res.status(400).json({ error: 'Je kunt jezelf niet verwijderen' });
    return;
  }
  
  if (userOps.count() <= 1) {
    res.status(400).json({ error: 'Je kunt de laatste beheerder niet verwijderen' });
    return;
  }
  
  userOps.delete(userId);
  res.json({ success: true });
});

// Change password
router.post('/change-password', (req: Request, res: Response) => {
  const { currentPassword, newPassword } = req.body;
  
  const user = userOps.findByUsername(req.session.user!.username);
  if (!user) {
    res.status(404).json({ error: 'Gebruiker niet gevonden' });
    return;
  }
  
  if (!userOps.verifyPassword(user, currentPassword)) {
    res.status(400).json({ error: 'Huidig wachtwoord is onjuist' });
    return;
  }
  
  if (newPassword.length < 6) {
    res.status(400).json({ error: 'Wachtwoord moet minimaal 6 tekens zijn' });
    return;
  }
  
  userOps.updatePassword(req.session.user!.id, newPassword);
  res.json({ success: true });
});

export default router;