const express = require('express');
const { PrismaClient } = require('@prisma/client');
const { asyncHandler } = require('../middleware/errorHandler');
const { authenticateToken } = require('../middleware/auth');

const router = express.Router();
const prisma = new PrismaClient();

/**
 * Dashboard istatistikleri
 * GET /api/dashboard/stats
 */
router.get('/stats', [
  authenticateToken
], asyncHandler(async (req, res) => {
  const userId = req.user.id;

  // Kullanıcının listelerini al
  const userLists = await prisma.shoppingList.findMany({
    where: {
      OR: [
        { ownerId: userId },
        {
          members: {
            some: {
              userId: userId
            }
          }
        }
      ],
      isActive: true
    },
    include: {
      items: true
    }
  });

  // İstatistikleri hesapla
  const totalLists = userLists.length;
  const totalItems = userLists.reduce((sum, list) => sum + list.items.length, 0);
  const completedItems = userLists.reduce((sum, list) => 
    sum + list.items.filter(item => item.isPurchased).length, 0
  );
  const pendingItems = totalItems - completedItems;

  // Bu ayki harcama
  const currentMonth = new Date();
  currentMonth.setDate(1);
  currentMonth.setHours(0, 0, 0, 0);

  const monthlySpending = await prisma.listItem.aggregate({
    where: {
      isPurchased: true,
      purchasedAt: {
        gte: currentMonth
      },
      list: {
        OR: [
          { ownerId: userId },
          {
            members: {
              some: {
                userId: userId
              }
            }
          }
        ],
        isActive: true
      }
    },
    _sum: {
      price: true
    }
  });

  res.json({
    success: true,
    data: {
      totalLists,
      totalItems,
      completedItems,
      pendingItems,
      monthlySpending: monthlySpending._sum.price || 0,
      completionRate: totalItems > 0 ? Math.round((completedItems / totalItems) * 100) : 0
    }
  });
}));

/**
 * Son aktiviteler
 * GET /api/dashboard/activity
 */
router.get('/activity', [
  authenticateToken
], asyncHandler(async (req, res) => {
  const userId = req.user.id;
  const { limit = 10 } = req.query;

  // Son eklenen ürünler
  const recentItems = await prisma.listItem.findMany({
    where: {
      list: {
        OR: [
          { ownerId: userId },
          {
            members: {
              some: {
                userId: userId
              }
            }
          }
        ],
        isActive: true
      }
    },
    include: {
      list: {
        select: {
          id: true,
          name: true
        }
      },
      product: {
        select: {
          id: true,
          name: true
        }
      }
    },
    orderBy: {
      createdAt: 'desc'
    },
    take: parseInt(limit)
  });

  // Aktiviteleri formatla
  const activities = recentItems.map(item => ({
    id: item.id,
    type: item.isPurchased ? 'item_purchased' : 'item_added',
    message: item.isPurchased 
      ? `${item.product?.name || item.name} satın alındı`
      : `${item.product?.name || item.name} listeye eklendi`,
    listName: item.list.name,
    listId: item.list.id,
    createdAt: item.isPurchased ? item.purchasedAt : item.createdAt
  }));

  res.json({
    success: true,
    data: { activities }
  });
}));

module.exports = router;