const express = require('express');
const cors = require('cors');
const path = require('path');
const fs = require('fs');
const db = require('./db');
const scanner = require('./scanner');
const ai = require('./ai');

const app = express();
const PORT = process.env.PORT || 4000;

// Middleware
app.use(cors());
app.use(express.json());

// Serve static files from public directory
app.use(express.static(path.join(__dirname, 'public')));

// Create public directory if it doesn't exist
const publicDir = path.join(__dirname, 'public');
if (!fs.existsSync(publicDir)) {
  fs.mkdirSync(publicDir, { recursive: true });
}

// Track scanning state
let lastRunTime = null;
let scanProgress = { current: 0, total: 0, profileName: '' };

// API Routes

// --- PROFILES ---
app.get('/api/profiles', (req, res) => {
  try {
    let profiles = db.getProfiles();
    if (profiles.length === 0) {
      // Create a default profile if none exists
      db.addProfile('Default Profile', 0.85);
      profiles = db.getProfiles();
    }
    res.json(profiles);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.post('/api/profiles', (req, res) => {
  try {
    const { name, price_ratio } = req.body;
    db.addProfile(name, price_ratio || 0.85);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.put('/api/profiles/:id', (req, res) => {
  try {
    const { name, price_ratio } = req.body;
    db.updateProfile(req.params.id, name, price_ratio);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.delete('/api/profiles/:id', (req, res) => {
  try {
    db.deleteProfile(req.params.id);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// --- KEYWORDS ---
app.get('/api/profiles/:id/keywords', (req, res) => {
  try {
    const keywords = db.getKeywords(req.params.id);
    res.json(keywords);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.post('/api/profiles/:id/keywords', (req, res) => {
  try {
    const { part_number, keywords, target_price } = req.body;
    db.addKeyword(req.params.id, part_number, keywords, target_price);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.put('/api/keywords/:id', (req, res) => {
  try {
    const { part_number, keywords, target_price } = req.body;
    db.updateKeyword(req.params.id, part_number, keywords, target_price);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.post('/api/profiles/:id/keywords/bulk', (req, res) => {
  try {
    const { items } = req.body; // Array of {part_number, keywords, target_price}
    for (const item of items) {
      db.addKeyword(req.params.id, item.part_number, item.keywords, item.target_price);
    }
    res.json({ success: true, count: items.length });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.delete('/api/keywords/:id', (req, res) => {
  try {
    db.deleteKeyword(req.params.id);
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// --- ITEMS ---
// Get scan status
app.get('/api/status', (req, res) => {
  res.json({ isScanning, lastRunTime, scanProgress });
});

// Get all "waiting" PASS items for a profile
app.get('/api/items', (req, res) => {
  try {
    const { profile_id } = req.query;
    const items = db.getWaitingPassItems(profile_id);
    res.json(items);
  } catch (err) {
    console.error('Error fetching items:', err);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Update item review status
app.put('/api/items/:id/status', (req, res) => {
  try {
    const { id } = req.params;
    const { status } = req.body;
    
    if (!['waiting', 'done', 'skip'].includes(status)) {
      return res.status(400).json({ error: 'Invalid status' });
    }
    
    db.updateReviewStatus(id, status);
    res.json({ success: true, message: `Status updated to ${status}` });
  } catch (err) {
    console.error(`Error updating status for item ${req.params.id}:`, err);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Trigger a new scan
app.post('/api/scan', async (req, res) => {
  if (isScanning) {
    return res.status(400).json({ error: 'Scan is already running' });
  }
  
  const { profile_id } = req.body;
  if (!profile_id) {
    return res.status(400).json({ error: 'profile_id is required' });
  }

  isScanning = true;
  res.json({ success: true, message: 'Scan started in background' });
  
  try {
    console.log(`--- STARTING BACKGROUND SCAN FOR PROFILE ${profile_id} ---`);
    scanProgress = { current: 0, total: 0, profileName: '' };
    
    await scanner.runScannerCore(profile_id, (current, total, profileName) => {
      scanProgress = { current, total, profileName };
    });
    
    console.log('--- BACKGROUND SCAN FINISHED ---');
  } catch (err) {
    console.error('Error running scan:', err);
  } finally {
    isScanning = false;
    lastRunTime = new Date().toISOString();
    scanProgress = { current: 0, total: 0, profileName: '' };
  }
});

// Trigger AI on specific item
app.post('/api/items/:id/ai', async (req, res) => {
  try {
    const { id } = req.params;
    const item = db.getItem(id);
    if (!item) {
      return res.status(404).json({ error: 'Item not found' });
    }
    
    // Convert JSON strings back to objects for AI prompt
    item.detail_response = item.detail_response ? JSON.parse(item.detail_response) : null;
    
    const suggestion = await ai.getAiSuggestion(item);
    db.updateAiSuggestion(id, suggestion);
    
    res.json({ success: true, ai_suggestion: suggestion });
  } catch (err) {
    console.error(`Error requesting AI for item ${req.params.id}:`, err);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Default catch-all to index.html for SPA feel
app.use((req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Start server
app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});