const express = require('express');
const { body, query, validationResult } = require('express-validator');
const { db, logActivity } = require('../database/db');
const { adminAuth } = require('../middleware/auth');
const router = express.Router();
const bcrypt = require('bcrypt');
const crypto = require('crypto');
const fs = require('fs').promises;
const path = require('path');

// Create new event
router.post('/', adminAuth, [
  body('event_type').isIn(['wedding', 'birthday', 'corporate', 'other']),
  body('event_name').notEmpty().trim(),
  body('event_date').isDate(),
  body('host_email').isEmail().normalizeEmail(),
  body('admin_email').isEmail().normalizeEmail(),
  body('password').isLength({ min: 6 }),
  body('expiration_days').isInt({ min: 1, max: 365 }).optional(),
  body('welcome_message').optional().trim(),
  body('color_theme').optional().trim()
], async (req, res) => {
  try {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }
    
    const {
      event_type,
      event_name,
      event_date,
      host_email,
      admin_email,
      password,
      welcome_message = '',
      color_theme = 'default',
      expiration_days = 30
    } = req.body;
    
    // Generate unique slug
    const baseSlug = `${event_type}-${event_name.toLowerCase().replace(/[^a-z0-9]/g, '-')}-${event_date}`;
    let slug = baseSlug;
    let counter = 1;
    
    while (await db('events').where({ slug }).first()) {
      slug = `${baseSlug}-${counter}`;
      counter++;
    }
    
    // Generate share link
    const shareToken = crypto.randomBytes(16).toString('hex');
    const shareLink = `${process.env.FRONTEND_URL}/gallery/${slug}/${shareToken}`;
    
    // Hash password
    const password_hash = await bcrypt.hash(password, 10);
    
    // Calculate expiration date
    const expires_at = new Date();
    expires_at.setDate(expires_at.getDate() + expiration_days);
    
    // Create folder structure
    const storagePath = process.env.STORAGE_PATH || path.join(__dirname, '../../../storage');
    const eventPath = path.join(storagePath, 'events/active', slug);
    await fs.mkdir(path.join(eventPath, 'collages'), { recursive: true });
    await fs.mkdir(path.join(eventPath, 'individual'), { recursive: true });
    
    // Insert into database
    const [eventId] = await db('events').insert({
      slug,
      event_type,
      event_name,
      event_date,
      host_email,
      admin_email,
      password_hash,
      welcome_message,
      color_theme,
      share_link: shareLink,
      expires_at,
      created_at: new Date()
    });
    
    // Log activity
    await logActivity('event_created', 
      { event_type, expires_at }, 
      eventId, 
      { type: 'admin', id: req.user.id, name: req.user.username }
    );
    
    // Queue creation email
    await db('email_queue').insert({
      event_id: eventId,
      recipient_email: host_email,
      email_type: 'creation',
      email_data: JSON.stringify({
        event_name,
        share_link: shareLink,
        password,
        expires_at: expires_at.toISOString()
      }),
      created_at: new Date()
    });
    
    res.json({
      id: eventId,
      slug,
      event_name,
      event_type,
      share_link: shareLink,
      expires_at
    });
  } catch (error) {
    console.error('Error creating event:', error);
    res.status(500).json({ error: 'Failed to create event' });
  }
});

// Get all events with pagination and filters
router.get('/', adminAuth, async (req, res) => {
  try {
    const page = parseInt(req.query.page) || 1;
    const limit = parseInt(req.query.limit) || 20;
    const offset = (page - 1) * limit;
    const search = req.query.search || '';
    const status = req.query.status || 'all';
    const sortBy = req.query.sortBy || 'created_at';
    const sortOrder = req.query.sortOrder || 'desc';

    // Build query
    let query = db('events');
    
    // Apply search filter
    if (search) {
      query = query.where((builder) => {
        builder.where('event_name', 'like', `%${search}%`)
          .orWhere('admin_email', 'like', `%${search}%`)
          .orWhere('slug', 'like', `%${search}%`);
      });
    }

    // Apply status filter
    if (status === 'active') {
      query = query.where('is_active', true).where('is_archived', false);
    } else if (status === 'archived') {
      query = query.where('is_archived', true);
    } else if (status === 'inactive') {
      query = query.where('is_active', false).where('is_archived', false);
    } else if (status === 'expiring') {
      const sevenDaysFromNow = new Date();
      sevenDaysFromNow.setDate(sevenDaysFromNow.getDate() + 7);
      query = query
        .where('is_active', true)
        .where('is_archived', false)
        .where('expires_at', '<=', sevenDaysFromNow.toISOString())
        .where('expires_at', '>', new Date().toISOString());
    }

    // Get total count for pagination
    const countQuery = query.clone();
    const [{ count }] = await countQuery.count('* as count');

    // Apply sorting and pagination
    const events = await query
      .orderBy(sortBy, sortOrder)
      .limit(limit)
      .offset(offset);

    // Get photo counts for each event
    const eventIds = events.map(e => e.id);
    const photoCounts = await db('photos')
      .whereIn('event_id', eventIds)
      .groupBy('event_id')
      .select('event_id')
      .count('* as count');

    // Map photo counts to events
    const photoCountMap = photoCounts.reduce((acc, { event_id, count }) => {
      acc[event_id] = parseInt(count);
      return acc;
    }, {});

    // Add photo counts to events
    const eventsWithCounts = events.map(event => ({
      ...event,
      photo_count: photoCountMap[event.id] || 0
    }));

    res.json({
      events: eventsWithCounts,
      pagination: {
        page,
        limit,
        total: parseInt(count),
        totalPages: Math.ceil(count / limit)
      }
    });
  } catch (error) {
    console.error('Error fetching events:', error);
    res.status(500).json({ error: 'Failed to fetch events' });
  }
});

// Get single event details
router.get('/:id', adminAuth, async (req, res) => {
  try {
    const { id } = req.params;
    
    const event = await db('events')
      .where('id', id)
      .first();

    if (!event) {
      return res.status(404).json({ error: 'Event not found' });
    }

    // Get photo count
    const [{ count: photoCount }] = await db('photos')
      .where('event_id', id)
      .count('* as count');

    // Get total size
    const [{ totalSize }] = await db('photos')
      .where('event_id', id)
      .sum('size_bytes as totalSize');

    // Get recent photos
    const recentPhotos = await db('photos')
      .where('event_id', id)
      .orderBy('uploaded_at', 'desc')
      .limit(10)
      .select('filename', 'type', 'size_bytes', 'uploaded_at');

    res.json({
      ...event,
      photo_count: parseInt(photoCount) || 0,
      total_size: parseInt(totalSize) || 0,
      recent_photos: recentPhotos
    });
  } catch (error) {
    console.error('Error fetching event:', error);
    res.status(500).json({ error: 'Failed to fetch event details' });
  }
});

// Update event
router.put('/:id', adminAuth, [
  body('event_name').optional().trim().notEmpty(),
  body('admin_email').optional().isEmail(),
  body('is_active').optional().isBoolean(),
  body('expires_at').optional().isISO8601(),
  body('welcome_message').optional().trim(),
  body('color_theme').optional().trim()
], async (req, res) => {
  try {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }

    const { id } = req.params;
    const updates = req.body;

    // Check if event exists
    const event = await db('events').where('id', id).first();
    if (!event) {
      return res.status(404).json({ error: 'Event not found' });
    }

    // Update event
    await db('events')
      .where('id', id)
      .update({
        ...updates,
        updated_at: new Date()
      });

    // Log activity
    await logActivity('event_updated',
      { changes: Object.keys(updates), eventName: event.event_name },
      id,
      { type: 'admin', id: req.user.id, name: req.user.username }
    );

    res.json({ message: 'Event updated successfully' });
  } catch (error) {
    console.error('Error updating event:', error);
    res.status(500).json({ error: 'Failed to update event' });
  }
});

// Delete event
router.delete('/:id', adminAuth, async (req, res) => {
  try {
    const { id } = req.params;

    // Check if event exists
    const event = await db('events').where('id', id).first();
    if (!event) {
      return res.status(404).json({ error: 'Event not found' });
    }

    // Delete associated photos
    await db('photos').where('event_id', id).del();

    // Delete event
    await db('events').where('id', id).del();

    // Log activity
    await logActivity('event_deleted',
      { event_name: event.event_name },
      null,
      { type: 'admin', id: req.user.id, name: req.user.username }
    );

    res.json({ message: 'Event deleted successfully' });
  } catch (error) {
    console.error('Error deleting event:', error);
    res.status(500).json({ error: 'Failed to delete event' });
  }
});

// Toggle event status
router.post('/:id/toggle-status', adminAuth, async (req, res) => {
  try {
    const { id } = req.params;

    const event = await db('events').where('id', id).first();
    if (!event) {
      return res.status(404).json({ error: 'Event not found' });
    }

    const newStatus = !event.is_active;
    await db('events')
      .where('id', id)
      .update({
        is_active: newStatus,
        updated_at: new Date()
      });

    // Log activity
    await logActivity(newStatus ? 'event_activated' : 'event_deactivated',
      { eventName: event.event_name },
      id,
      { type: 'admin', id: req.user.id, name: req.user.username }
    );

    res.json({ 
      message: `Event ${newStatus ? 'activated' : 'deactivated'} successfully`,
      is_active: newStatus
    });
  } catch (error) {
    console.error('Error toggling event status:', error);
    res.status(500).json({ error: 'Failed to toggle event status' });
  }
});

// Archive event
router.post('/:id/archive', adminAuth, async (req, res) => {
  try {
    const { id } = req.params;

    const event = await db('events').where('id', id).first();
    if (!event) {
      return res.status(404).json({ error: 'Event not found' });
    }

    if (event.is_archived) {
      return res.status(400).json({ error: 'Event is already archived' });
    }

    await db('events')
      .where('id', id)
      .update({
        is_archived: true,
        is_active: false,
        archived_at: new Date(),
        updated_at: new Date()
      });

    // Log activity
    await logActivity('event_archived',
      { eventName: event.event_name },
      id,
      { type: 'admin', id: req.user.id, name: req.user.username }
    );

    res.json({ message: 'Event archived successfully' });
  } catch (error) {
    console.error('Error archiving event:', error);
    res.status(500).json({ error: 'Failed to archive event' });
  }
});

module.exports = router;