const express = require('express');
const router = express.Router();
const pool = require('../db');
const fs = require('fs');
const path = require('path');
const crypto = require('crypto');
const { db } = require('../activityDb');

const ALGORITHM = 'aes-256-cbc';
const SECRET_KEY = crypto.createHash('sha256').update(process.env.CRYPTO_KEY || 'default_secret_key_12345').digest();
const IV_LENGTH = 16;

function encrypt(text) {
  const iv = crypto.randomBytes(IV_LENGTH);
  const cipher = crypto.createCipheriv(ALGORITHM, SECRET_KEY, iv);
  let encrypted = cipher.update(text, 'utf8', 'hex');
  encrypted += cipher.final('hex');
  return iv.toString('hex') + ':' + encrypted;
}

function decrypt(text) {
  const textParts = text.split(':');
  const iv = Buffer.from(textParts.shift(), 'hex');
  const encryptedText = Buffer.from(textParts.join(':'), 'hex');
  const decipher = crypto.createDecipheriv(ALGORITHM, SECRET_KEY, iv);
  let decrypted = decipher.update(encryptedText, 'hex', 'utf8');
  decrypted += decipher.final('utf8');
  return decrypted;
}

// Ensure SQLite table exists for phrases
db.exec(`
  CREATE TABLE IF NOT EXISTS frasi_cache (
    id      INTEGER PRIMARY KEY AUTOINCREMENT,
    tipo    TEXT,
    testo   TEXT
  )
`);

// Seed function to import plain-text files into SQLite cache
function seedPhrases() {
  try {
    const countRow = db.prepare("SELECT COUNT(*) AS count FROM frasi_cache").get();
    if (countRow.count === 0) {
      console.log('[Phrases Seed] SQLite frasi_cache is empty. Seeding...');
      
      const seedFile = (fileName, type) => {
        const txtPath = path.join(__dirname, `../public/${fileName}`);
        if (fs.existsSync(txtPath)) {
          const text = fs.readFileSync(txtPath, 'utf8');
          const lines = text.split('\n').map(line => line.trim()).filter(line => line.length > 0);
          
          const insertStmt = db.prepare("INSERT INTO frasi_cache (tipo, testo) VALUES (?, ?)");
          db.transaction(() => {
            for (const line of lines) {
              insertStmt.run(type, encrypt(line));
            }
          })();
          console.log(`[Phrases Seed] Successfully seeded ${lines.length} encrypted ${type} phrases.`);
        }
      };

      seedFile('demotivational.txt', 'demotivational');
      seedFile('motivational.txt', 'motivational');
    }
  } catch (err) {
    console.error('[Phrases Seed] Seeding failed:', err.message);
  }
}

seedPhrases();


// GET /api/dashboard/stats — Dashboard statistics
router.get('/stats', async (req, res) => {
  const activeAgentId = parseInt(req.headers['x-agent-id'], 10) || 1;
  try {
    // All queries in parallel for speed
    const [
      byState,
      byPriority,
      byQueue,
      todayCount,
      weekCount,
      totalOpen,
      recentTickets,
      escalated,
      myOpenCount,
    ] = await Promise.all([
      // Tickets by state (only open-ish states)
      pool.query(
        `SELECT ts.name AS state, tst.name AS state_type, COUNT(*) AS count
         FROM ticket t
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_state_type tst ON ts.type_id = tst.id
         WHERE tst.name IN ('new', 'open', 'pending reminder', 'pending auto')
         GROUP BY ts.name, tst.name
         ORDER BY count DESC`
      ),
      // Tickets by priority (open only)
      pool.query(
        `SELECT tp.name AS priority, tp.color, COUNT(*) AS count
         FROM ticket t
         JOIN ticket_priority tp ON t.ticket_priority_id = tp.id
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_state_type tst ON ts.type_id = tst.id
         WHERE tst.name IN ('new', 'open', 'pending reminder', 'pending auto')
         GROUP BY tp.name, tp.color, tp.id
         ORDER BY tp.id`
      ),
      // Tickets by queue (open only, top 10)
      pool.query(
        `SELECT q.name AS queue, COUNT(*) AS count
         FROM ticket t
         JOIN queue q ON t.queue_id = q.id
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_state_type tst ON ts.type_id = tst.id
         WHERE tst.name IN ('new', 'open', 'pending reminder', 'pending auto')
         GROUP BY q.name
         ORDER BY count DESC
         LIMIT 10`
      ),
      // Created today
      pool.query(
        `SELECT COUNT(*) AS count FROM ticket
         WHERE create_time >= CURRENT_DATE`
      ),
      // Created this week
      pool.query(
        `SELECT COUNT(*) AS count FROM ticket
         WHERE create_time >= date_trunc('week', CURRENT_DATE)`
      ),
      // Total open
      pool.query(
        `SELECT COUNT(*) AS count
         FROM ticket t
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_state_type tst ON ts.type_id = tst.id
         WHERE tst.name IN ('new', 'open', 'pending reminder', 'pending auto')`
      ),
      // 10 most recent tickets
      pool.query(
        `SELECT t.id, t.tn, t.title, ts.name AS state_name,
                tp.name AS priority_name, tp.color AS priority_color,
                q.name AS queue_name, t.create_time
         FROM ticket t
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_priority tp ON t.ticket_priority_id = tp.id
         JOIN queue q ON t.queue_id = q.id
         ORDER BY t.create_time DESC
         LIMIT 10`
      ),
      // Escalated tickets
      pool.query(
        `SELECT COUNT(*) AS count FROM ticket
         WHERE escalation_time > 0
           AND escalation_time < EXTRACT(EPOCH FROM NOW())`
      ),
      // My open tickets count
      pool.query(
        `SELECT COUNT(*) AS count
         FROM ticket t
         JOIN ticket_state ts ON t.ticket_state_id = ts.id
         JOIN ticket_state_type tst ON ts.type_id = tst.id
         WHERE tst.name IN ('new', 'open', 'pending reminder', 'pending auto')
           AND t.user_id = $1`,
        [activeAgentId]
      ),
    ]);

    res.json({
      by_state: byState.rows,
      by_priority: byPriority.rows,
      by_queue: byQueue.rows,
      created_today: parseInt(todayCount.rows[0].count),
      created_this_week: parseInt(weekCount.rows[0].count),
      total_open: parseInt(totalOpen.rows[0].count),
      recent_tickets: recentTickets.rows,
      escalated: parseInt(escalated.rows[0].count),
      total_my_open: parseInt(myOpenCount.rows[0].count),
    });
  } catch (err) {
    console.error('Error fetching dashboard stats:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/dashboard/phrases — Get decrypted phrases from SQLite cache
router.get('/phrases', (req, res) => {
  const { tipo = 'demotivational' } = req.query;
  try {
    const rows = db.prepare("SELECT testo FROM frasi_cache WHERE tipo = ?").all(tipo);
    const decryptedPhrases = rows.map(row => {
      try {
        return decrypt(row.testo);
      } catch (decErr) {
        console.warn('[Decrypt Phrase] Failed to decrypt phrase:', decErr.message);
        return null;
      }
    }).filter(Boolean);

    res.json(decryptedPhrases);
  } catch (err) {
    console.error('Error fetching decrypted phrases:', err);
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;