const express = require('express');
const cors = require('cors');
const path = require('node:path');
const db = require('./db');
const { lookupBarcode } = require('./barcode');

const app = express();
const PORT = process.env.PORT || 3000;

app.use(cors());
app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

// Metadata definitions
const CATEGORIES = [
  { id: 'Dairy & Cheese', name: 'Dairy & Cheese', icon: 'milk', color: '#3b82f6' },
  { id: 'Meat & Fish', name: 'Meat & Fish', icon: 'beef', color: '#ef4444' },
  { id: 'Produce', name: 'Fruits & Veggies', icon: 'apple', color: '#10b981' },
  { id: 'Beverages', name: 'Drinks & Beverages', icon: 'cup-soda', color: '#06b6d4' },
  { id: 'Sauces & Condiments', name: 'Sauces & Condiments', icon: 'flask-conical', color: '#f59e0b' },
  { id: 'Bakery', name: 'Bakery & Bread', icon: 'croissant', color: '#d97706' },
  { id: 'Prepared & Leftovers', name: 'Leftovers & Meals', icon: 'utensils', color: '#8b5cf6' },
  { id: 'Snacks & Sweets', name: 'Snacks & Sweets', icon: 'cookie', color: '#ec4899' },
  { id: 'General', name: 'General / Other', icon: 'package', color: '#6b7280' }
];

const LOCATIONS = [
  'Fridge - Top Shelf',
  'Fridge - Middle Shelf',
  'Fridge - Bottom Shelf',
  'Fridge - Crisper Drawer',
  'Fridge - Door Rack',
  'Freezer - Top Drawer',
  'Freezer - Bottom Drawer',
  'Pantry / Cupboard'
];

const UNITS = [
  { id: 'g', label: 'Grams (g)', isWeight: true, step: 50 },
  { id: 'kg', label: 'Kilograms (kg)', isWeight: true, step: 0.1 },
  { id: 'ml', label: 'Milliliters (ml)', isVolume: true, step: 100 },
  { id: 'l', label: 'Liters (L)', isVolume: true, step: 0.5 },
  { id: 'pcs', label: 'Pieces (Stk / pcs)', isCount: true, step: 1 },
  { id: 'slices', label: 'Slices', isCount: true, step: 1 },
  { id: 'pack', label: 'Pack / Package', isCount: true, step: 1 }
];

// Health Check
app.get('/health', (req, res) => {
  res.json({ status: 'ok', uptime: process.uptime(), timestamp: new Date().toISOString() });
});

// Meta endpoint
app.get('/api/meta', (req, res) => {
  res.json({
    categories: CATEGORIES,
    locations: LOCATIONS,
    units: UNITS
  });
});

// Stats endpoint
app.get('/api/stats', (req, res) => {
  try {
    const stats = db.getStats();
    res.json(stats);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Activity logs
app.get('/api/activity', (req, res) => {
  try {
    const limit = parseInt(req.query.limit, 10) || 50;
    const logs = db.getActivityLogs(limit);
    res.json(logs);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Barcode lookup
app.get('/api/barcode/:code', async (req, res) => {
  const barcode = req.params.code;
  if (!barcode) {
    return res.status(400).json({ error: 'Barcode parameter is required' });
  }

  // First check if user previously stored an item with this barcode
  const existing = db.getItemByBarcode(barcode);
  if (existing) {
    return res.json({
      found: true,
      fromLocal: true,
      barcode: existing.barcode,
      name: existing.name,
      brand: existing.brand || '',
      category: existing.category || 'General',
      location: existing.location || 'Fridge - Middle Shelf',
      quantity: existing.initial_quantity || existing.quantity,
      initial_quantity: existing.initial_quantity || existing.quantity,
      unit: existing.unit || 'g',
      image_url: existing.image_url || ''
    });
  }

  // Lookup in Open Food Facts
  const product = await lookupBarcode(barcode);
  if (product) {
    return res.json({
      ...product,
      fromLocal: false
    });
  }

  res.status(404).json({
    found: false,
    barcode: barcode,
    message: 'Barcode not found in database or Open Food Facts'
  });
});

// List items
app.get('/api/items', (req, res) => {
  try {
    const { search, category, location, status } = req.query;
    const items = db.getAllItems({ search, category, location, status });
    res.json(items);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Get single item
app.get('/api/items/:id', (req, res) => {
  try {
    const item = db.getItemById(req.params.id);
    if (!item) return res.status(404).json({ error: 'Item not found' });
    res.json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Create item
app.post('/api/items', (req, res) => {
  try {
    const { name, quantity } = req.body;
    if (!name || name.trim() === '') {
      return res.status(400).json({ error: 'Item name is required' });
    }
    if (quantity === undefined || isNaN(Number(quantity)) || Number(quantity) < 0) {
      return res.status(400).json({ error: 'Valid quantity is required' });
    }

    const item = db.createItem(req.body);
    res.status(201).json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Update item
app.put('/api/items/:id', (req, res) => {
  try {
    const item = db.updateItem(req.params.id, req.body);
    if (!item) return res.status(404).json({ error: 'Item not found' });
    res.json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Quick adjust quantity (grams / count / delta / slider)
app.patch('/api/items/:id/quantity', (req, res) => {
  try {
    const { newQuantity, delta, markOpened } = req.body;
    if (newQuantity === undefined && delta === undefined) {
      return res.status(400).json({ error: 'Either newQuantity or delta must be provided' });
    }

    const item = db.adjustQuantity(req.params.id, { newQuantity, delta, markOpened });
    if (!item) return res.status(404).json({ error: 'Item not found' });
    res.json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Add whole packet (+1 full pack size)
app.post('/api/items/:id/add-packet', (req, res) => {
  try {
    const count = parseInt(req.body.count, 10) || 1;
    const item = db.addPacket(req.params.id, count);
    if (!item) return res.status(404).json({ error: 'Item not found' });
    res.json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Remove whole packet (-1 full pack size)
app.post('/api/items/:id/remove-packet', (req, res) => {
  try {
    const count = parseInt(req.body.count, 10) || 1;
    const item = db.removePacket(req.params.id, count);
    if (!item) return res.status(404).json({ error: 'Item not found' });
    res.json(item);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Delete item
app.delete('/api/items/:id', (req, res) => {
  try {
    const success = db.deleteItem(req.params.id);
    if (!success) return res.status(404).json({ error: 'Item not found' });
    res.json({ success: true, message: 'Item removed' });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Seed sample fridge data if empty
app.post('/api/seed', (req, res) => {
  try {
    const existing = db.getAllItems();
    if (existing.length > 0 && !req.query.force) {
      return res.json({ message: 'Fridge already contains items', count: existing.length });
    }

    const today = new Date();
    const addDays = (d) => {
      const target = new Date(today.getTime() + d * 24 * 60 * 60 * 1000);
      return target.toISOString().slice(0, 10);
    };

    const samples = [
      {
        name: 'Gouda Cheese (Jung)',
        brand: 'Milbona',
        barcode: '4056489123456',
        category: 'Dairy & Cheese',
        location: 'Fridge - Middle Shelf',
        quantity: 200,
        initial_quantity: 400,
        unit: 'g',
        is_opened: 1,
        opened_at: addDays(-2),
        expiry_date: addDays(6),
        notes: 'Opened, about half remaining for sandwiches'
      },
      {
        name: 'Whole Milk 3.5%',
        brand: 'Weihenstephan',
        barcode: '4008452023451',
        category: 'Dairy & Cheese',
        location: 'Fridge - Door Rack',
        quantity: 650,
        initial_quantity: 1000,
        unit: 'ml',
        is_opened: 1,
        opened_at: addDays(-1),
        expiry_date: addDays(3),
        notes: 'Carton opened yesterday'
      },
      {
        name: 'Organic Greek Yogurt',
        brand: 'Andechser Natur',
        barcode: '4005040001234',
        category: 'Dairy & Cheese',
        location: 'Fridge - Top Shelf',
        quantity: 500,
        initial_quantity: 500,
        unit: 'g',
        is_opened: 0,
        expiry_date: addDays(12),
        notes: 'Unopened 500g cup'
      },
      {
        name: 'Chicken Breast Fillet',
        brand: 'Bauerngut',
        barcode: '4012345678901',
        category: 'Meat & Fish',
        location: 'Fridge - Bottom Shelf',
        quantity: 350,
        initial_quantity: 400,
        unit: 'g',
        is_opened: 1,
        opened_at: addDays(0),
        expiry_date: addDays(1),
        notes: 'Cook today or freeze!'
      },
      {
        name: 'Fresh Cherry Tomatoes',
        brand: 'Bio',
        category: 'Produce',
        location: 'Fridge - Crisper Drawer',
        quantity: 180,
        initial_quantity: 250,
        unit: 'g',
        is_opened: 1,
        expiry_date: addDays(4),
        notes: 'Sweet snack tomatoes'
      },
      {
        name: 'Dijon Mustard',
        brand: 'Maille',
        barcode: '3036810200028',
        category: 'Sauces & Condiments',
        location: 'Fridge - Door Rack',
        quantity: 140,
        initial_quantity: 215,
        unit: 'g',
        is_opened: 1,
        expiry_date: addDays(90),
        notes: 'In door rack'
      },
      {
        name: 'Butter (Irish Pure)',
        brand: 'Kerrygold',
        barcode: '5011010001018',
        category: 'Dairy & Cheese',
        location: 'Fridge - Door Rack',
        quantity: 190,
        initial_quantity: 250,
        unit: 'g',
        is_opened: 1,
        expiry_date: addDays(25),
        notes: 'In butter dish'
      },
      {
        name: 'Homemade Pasta Bolognese',
        brand: '',
        category: 'Prepared & Leftovers',
        location: 'Fridge - Top Shelf',
        quantity: 1,
        initial_quantity: 1,
        unit: 'pack',
        is_opened: 1,
        opened_at: addDays(-1),
        expiry_date: addDays(1),
        notes: 'Glass container, 1 portion'
      },
      {
        name: 'Orange Juice 100%',
        brand: 'Innocent',
        barcode: '5038862112345',
        category: 'Beverages',
        location: 'Fridge - Door Rack',
        quantity: 900,
        initial_quantity: 900,
        unit: 'ml',
        is_opened: 0,
        expiry_date: addDays(14)
      }
    ];

    for (const sample of samples) {
      db.createItem(sample);
    }

    res.json({ message: 'Seed complete', created: samples.length });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Catch-all route to serve the Single Page Application
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Start Server
if (require.main === module) {
  // Check if initial seed is needed on first launch
  const items = db.getAllItems();
  if (items.length === 0) {
    console.log('Fridge is empty. Pre-seeding sample items for initial experience...');
    // Seed initial items
    const today = new Date();
    const addDays = (d) => new Date(today.getTime() + d * 24 * 60 * 60 * 1000).toISOString().slice(0, 10);
    [
      { name: 'Gouda Cheese', brand: 'Milbona', barcode: '4056489123456', category: 'Dairy & Cheese', location: 'Fridge - Middle Shelf', quantity: 200, initial_quantity: 400, unit: 'g', is_opened: 1, expiry_date: addDays(5), notes: 'Half pack left' },
      { name: 'Fresh Milk 3.5%', brand: 'Weihenstephan', barcode: '4008452023451', category: 'Dairy & Cheese', location: 'Fridge - Door Rack', quantity: 700, initial_quantity: 1000, unit: 'ml', is_opened: 1, expiry_date: addDays(3), notes: 'Opened' },
      { name: 'Butter', brand: 'Kerrygold', barcode: '5011010001018', category: 'Dairy & Cheese', location: 'Fridge - Door Rack', quantity: 210, initial_quantity: 250, unit: 'g', is_opened: 1, expiry_date: addDays(20) },
      { name: 'Chicken Breast', brand: 'Bio', category: 'Meat & Fish', location: 'Fridge - Bottom Shelf', quantity: 400, initial_quantity: 400, unit: 'g', is_opened: 0, expiry_date: addDays(2), notes: 'Cook soon' },
      { name: 'Cherry Tomatoes', category: 'Produce', location: 'Fridge - Crisper Drawer', quantity: 180, initial_quantity: 250, unit: 'g', is_opened: 1, expiry_date: addDays(4) },
      { name: 'Dijon Mustard', brand: 'Maille', barcode: '3036810200028', category: 'Sauces & Condiments', location: 'Fridge - Door Rack', quantity: 150, initial_quantity: 215, unit: 'g', is_opened: 1, expiry_date: addDays(60) }
    ].forEach(item => db.createItem(item));
  }

  app.listen(PORT, '0.0.0.0', () => {
    console.log(`🧊 Fridger server running at http://0.0.0.0:${PORT}`);
  });
}

module.exports = app;