const express = require('express');
const { db } = require('../database/db');
const { adminAuth } = require('../middleware/auth');
const router = express.Router();

// Get dashboard statistics
router.get('/stats', adminAuth, async (req, res) => {
  try {
    // Get active events count
    const activeEvents = await db('events')
      .where('is_active', true)
      .where('is_archived', false)
      .count('id as count')
      .first();

    // Get events expiring within 7 days
    const expiringEvents = await db('events')
      .where('is_active', true)
      .where('is_archived', false)
      .whereRaw('expires_at <= datetime("now", "+7 days")')
      .whereRaw('expires_at > datetime("now")')
      .count('id as count')
      .first();

    // Get total photos count
    const totalPhotos = await db('photos')
      .count('id as count')
      .first();

    // Get storage usage (sum of all photo sizes)
    const storageUsed = await db('photos')
      .sum('size_bytes as total')
      .first();

    // Get total views (last 30 days)
    const totalViews = await db('access_logs')
      .where('action', 'view')
      .whereRaw('timestamp >= datetime("now", "-30 days")')
      .count('id as count')
      .first();

    // Get total downloads (last 30 days)
    const totalDownloads = await db('access_logs')
      .where('action', 'download')
      .whereRaw('timestamp >= datetime("now", "-30 days")')
      .count('id as count')
      .first();

    // Calculate trends (compare with previous 30 days)
    const previousViews = await db('access_logs')
      .where('action', 'view')
      .whereRaw('timestamp >= datetime("now", "-60 days")')
      .whereRaw('timestamp < datetime("now", "-30 days")')
      .count('id as count')
      .first();

    const previousDownloads = await db('access_logs')
      .where('action', 'download')
      .whereRaw('timestamp >= datetime("now", "-60 days")')
      .whereRaw('timestamp < datetime("now", "-30 days")')
      .count('id as count')
      .first();

    // Calculate trend percentages
    const viewsTrend = previousViews.count > 0 
      ? ((totalViews.count - previousViews.count) / previousViews.count) * 100 
      : 0;
    
    const downloadsTrend = previousDownloads.count > 0
      ? ((totalDownloads.count - previousDownloads.count) / previousDownloads.count) * 100
      : 0;

    res.json({
      activeEvents: activeEvents.count || 0,
      expiringEvents: expiringEvents.count || 0,
      totalPhotos: totalPhotos.count || 0,
      storageUsed: storageUsed.total || 0,
      totalViews: totalViews.count || 0,
      totalDownloads: totalDownloads.count || 0,
      viewsTrend: Math.round(viewsTrend * 10) / 10,
      downloadsTrend: Math.round(downloadsTrend * 10) / 10
    });
  } catch (error) {
    console.error('Dashboard stats error:', error);
    res.status(500).json({ error: 'Failed to fetch dashboard statistics' });
  }
});

// Get recent activity
router.get('/activity', adminAuth, async (req, res) => {
  try {
    const limit = parseInt(req.query.limit) || 10;
    
    const activities = await db('activity_logs')
      .select('activity_logs.*', 'events.event_name')
      .leftJoin('events', 'activity_logs.event_id', 'events.id')
      .orderBy('activity_logs.created_at', 'desc')
      .limit(limit);

    // Format activities
    const formattedActivities = activities.map(activity => ({
      id: activity.id,
      type: activity.activity_type,
      actorType: activity.actor_type,
      actorName: activity.actor_name,
      eventName: activity.event_name,
      metadata: activity.metadata ? JSON.parse(activity.metadata) : {},
      createdAt: activity.created_at
    }));

    res.json(formattedActivities);
  } catch (error) {
    console.error('Activity log error:', error);
    res.status(500).json({ error: 'Failed to fetch activity log' });
  }
});

// Get analytics data for charts
router.get('/analytics', adminAuth, async (req, res) => {
  try {
    const days = parseInt(req.query.days) || 7;
    
    // Generate date range
    const dates = [];
    for (let i = days - 1; i >= 0; i--) {
      dates.push({
        date: new Date(Date.now() - i * 24 * 60 * 60 * 1000).toISOString().split('T')[0],
        views: 0,
        downloads: 0,
        uniqueVisitors: 0
      });
    }

    // Get views per day
    const viewsData = await db('access_logs')
      .select(db.raw('DATE(timestamp) as date'), db.raw('COUNT(*) as count'))
      .where('action', 'view')
      .whereRaw(`timestamp >= datetime("now", "-${days} days")`)
      .groupByRaw('DATE(timestamp)');

    // Get downloads per day
    const downloadsData = await db('access_logs')
      .select(db.raw('DATE(timestamp) as date'), db.raw('COUNT(*) as count'))
      .where('action', 'download')
      .whereRaw(`timestamp >= datetime("now", "-${days} days")`)
      .groupByRaw('DATE(timestamp)');

    // Get unique visitors per day
    const visitorsData = await db('access_logs')
      .select(db.raw('DATE(timestamp) as date'), db.raw('COUNT(DISTINCT ip_address) as count'))
      .whereRaw(`timestamp >= datetime("now", "-${days} days")`)
      .groupByRaw('DATE(timestamp)');

    // Merge data into dates array
    viewsData.forEach(row => {
      const dateObj = dates.find(d => d.date === row.date);
      if (dateObj) dateObj.views = row.count;
    });

    downloadsData.forEach(row => {
      const dateObj = dates.find(d => d.date === row.date);
      if (dateObj) dateObj.downloads = row.count;
    });

    visitorsData.forEach(row => {
      const dateObj = dates.find(d => d.date === row.date);
      if (dateObj) dateObj.uniqueVisitors = row.count;
    });

    // Get top galleries by views
    const topGalleries = await db('access_logs')
      .select('events.event_name', 'events.slug')
      .select(db.raw('COUNT(*) as views'))
      .join('events', 'access_logs.event_id', 'events.id')
      .where('access_logs.action', 'view')
      .whereRaw(`access_logs.timestamp >= datetime("now", "-${days} days")`)
      .groupBy('events.id')
      .orderBy('views', 'desc')
      .limit(5);

    // Get device breakdown (simplified - based on user agent)
    const deviceData = await db('access_logs')
      .select(
        db.raw(`
          CASE 
            WHEN user_agent LIKE '%Mobile%' THEN 'mobile'
            WHEN user_agent LIKE '%Tablet%' OR user_agent LIKE '%iPad%' THEN 'tablet'
            ELSE 'desktop'
          END as device_type
        `),
        db.raw('COUNT(*) as count')
      )
      .whereRaw(`timestamp >= datetime("now", "-${days} days")`)
      .groupBy('device_type');

    const totalDevices = deviceData.reduce((sum, d) => sum + d.count, 0);
    const devices = {
      desktop: 0,
      mobile: 0,
      tablet: 0
    };

    deviceData.forEach(d => {
      devices[d.device_type] = Math.round((d.count / totalDevices) * 100);
    });

    res.json({
      chartData: dates,
      topGalleries,
      devices
    });
  } catch (error) {
    console.error('Analytics error:', error);
    res.status(500).json({ error: 'Failed to fetch analytics data' });
  }
});

module.exports = router;