const express = require('express');
const router = express.Router();
const pool = require('../db');

// In-memory cache for customer users fetched from LDAP
let ldapCustomerUsersCache = [];

// Helper for OTRS CE GenericInterface REST API calls
async function otrsRequest(method, path, bodyData = {}) {
  const OTRS_API_USER = process.env.OTRS_API_USER;
  const OTRS_API_PASSWORD = process.env.OTRS_API_PASSWORD;
  const OTRS_API_URL = process.env.OTRS_API_URL;

  if (!OTRS_API_URL || !OTRS_API_USER) {
    return null;
  }
  const url = `${OTRS_API_URL.replace(/\/$/, '')}${path.startsWith('/') ? path : '/' + path}`;
  const payload = {
    UserLogin: OTRS_API_USER,
    Password: OTRS_API_PASSWORD,
    ...bodyData
  };

  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), 15000);

  try {
    const response = await fetch(url, {
      method,
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
      signal: controller.signal
    });
    clearTimeout(timeoutId);

    if (!response.ok) {
      const errorText = await response.text();
      throw new Error(`OTRS REST API error (${response.status}): ${errorText}`);
    }
    return await response.json();
  } catch (err) {
    clearTimeout(timeoutId);
    if (err.name === 'AbortError') {
      throw new Error('OTRS REST API request timed out (15s limit exceeded)');
    }
    throw err;
  }
}


// GET /api/queues — Active queues
router.get('/queues', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT q.id, q.name, q.comments
       FROM queue q
       WHERE q.valid_id = 1
       ORDER BY q.name`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching queues:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/states — Ticket states with state type
router.get('/states', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT ts.id, ts.name, tst.name AS type_name
       FROM ticket_state ts
       JOIN ticket_state_type tst ON ts.type_id = tst.id
       WHERE ts.valid_id = 1
       ORDER BY ts.id`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching states:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/priorities — Ticket priorities
router.get('/priorities', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT id, name, color
       FROM ticket_priority
       WHERE valid_id = 1
       ORDER BY id`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching priorities:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/users — Active agents/operators
router.get('/users', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT id, login, first_name, last_name, title
       FROM users
       WHERE valid_id = 1
       ORDER BY last_name, first_name`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching users:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/config — Application config
router.get('/config', (req, res) => {
  res.json({
    defaultAgentLogin: process.env.OTRS_API_USER || '',
    dailyTargetTime: parseInt(process.env.DAILY_TARGET_TIME, 10) || 480
  });
});

// GET /api/users/time-today — Get sum of today's time units for active agent
router.get('/users/time-today', async (req, res) => {
  try {
    const operatorId = parseInt(req.headers['x-agent-id'], 10) || 1;
    const result = await pool.query(
      `SELECT COALESCE(SUM(time_unit), 0) AS total_today
       FROM time_accounting
       WHERE create_by = $1 AND DATE(create_time) = CURRENT_DATE`,
      [operatorId]
    );
    res.json({ totalToday: parseFloat(result.rows[0].total_today) });
  } catch (err) {
    console.error('Error fetching today\'s time units:', err);
    res.status(500).json({ error: err.message });
  }
});


// GET /api/types — Ticket types
router.get('/types', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT id, name
       FROM ticket_type
       WHERE valid_id = 1
       ORDER BY name`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching types:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/lock-types — Ticket lock types
router.get('/lock-types', async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT id, name FROM ticket_lock_type WHERE valid_id = 1 ORDER BY id`
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error fetching lock types:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/customer-companies/search — Search customer companies
router.get('/customer-companies/search', async (req, res) => {
  try {
    const { q = '' } = req.query;
    let result;
    if (!q) {
      result = await pool.query(
        `SELECT customer_id, name
         FROM customer_company
         WHERE valid_id = 1
         ORDER BY name
         LIMIT 20`
      );
    } else {
      const searchTerm = `%${q}%`;
      result = await pool.query(
        `SELECT customer_id, name
         FROM customer_company
         WHERE valid_id = 1 AND (
           customer_id ILIKE $1 OR
           name ILIKE $1
         )
         ORDER BY name
         LIMIT 20`,
        [searchTerm]
      );
    }
    res.json(result.rows);
  } catch (err) {
    console.error('Error searching customer companies:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/customer-users/search — Search customer users (supports LDAP via REST, fallbacks to DB)
router.get('/customer-users/search', async (req, res) => {
  const { q = '', customer_company_id } = req.query;

  // 1. Try to search via OTRS GenericInterface REST API if configured
  if (process.env.OTRS_API_URL && process.env.OTRS_API_USER) {
    // Search the in-memory cache first if it contains data
    if (ldapCustomerUsersCache.length > 0) {
      const searchTerms = q.toLowerCase().split(/\s+/).filter(Boolean);
      let matchedUsers = ldapCustomerUsersCache;
      
      if (searchTerms.length > 0) {
        matchedUsers = matchedUsers.filter(u => {
          const login = (u.login || '').toLowerCase();
          const email = (u.email || '').toLowerCase();
          const first = (u.first_name || '').toLowerCase();
          const last = (u.last_name || '').toLowerCase();
          const company = (u.customer_id || '').toLowerCase();
          
          return searchTerms.every(term => 
            login.includes(term) ||
            email.includes(term) ||
            first.includes(term) ||
            last.includes(term) ||
            company.includes(term)
          );
        });
      }

      if (customer_company_id) {
        matchedUsers = matchedUsers.filter(u => u.customer_id === customer_company_id);
      }

      return res.json(matchedUsers.slice(0, 20));
    }

    // Fallback to live API search if cache is not yet populated
    try {
      const searchPattern = q ? `*${q}*` : '*';
      const searchPayload = {
        Search: searchPattern,
        Valid: 1
      };
      if (customer_company_id) {
        searchPayload.CustomerID = customer_company_id;
      }

      const searchResult = await otrsRequest('POST', '/CustomerUserSearch', searchPayload);
      
      const searchData = (searchResult && searchResult.Data) || searchResult;
      if (searchData && searchData.CustomerUserID) {
        let logins = searchData.CustomerUserID;
        if (!Array.isArray(logins)) {
          logins = [logins];
        }
        logins = logins.slice(0, 20); // limit to 20 results
        
        // Fetch details for each login in parallel
        const detailsPromises = logins.map(async (login) => {
          try {
            const getResult = await otrsRequest('POST', '/CustomerUserGet', { UserLogin: login });
            const getData = (getResult && getResult.Data) || getResult;
            if (getData && getData.CustomerUser) {
              const u = getData.CustomerUser;
              return {
                login: u.UserLogin,
                email: u.UserEmail || '',
                first_name: u.UserFirstname || '',
                last_name: u.UserLastname || '',
                customer_id: u.UserCustomerID || ''
              };
            }
          } catch (getErr) {
            console.warn(`Failed to fetch details for customer user ${login}:`, getErr.message);
          }
          return null;
        });

        const users = (await Promise.all(detailsPromises)).filter(u => u !== null);
        return res.json(users);
      }
    } catch (restErr) {
      console.warn('Failed to search customer users via REST API, falling back to database query:', restErr.message);
    }
  }

  // 2. Fallback to local DB query
  try {
    let queryText;
    let queryParams;
    if (q) {
      const searchTerm = `%${q}%`;
      queryText = `
        SELECT login, email, first_name, last_name, customer_id
        FROM customer_user
        WHERE valid_id = 1 AND (
          login ILIKE $1 OR
          email ILIKE $1 OR
          first_name ILIKE $1 OR
          last_name ILIKE $1
        )
      `;
      queryParams = [searchTerm];
      if (customer_company_id) {
        queryText += ` AND customer_id = $2`;
        queryParams.push(customer_company_id);
      }
    } else {
      queryText = `
        SELECT login, email, first_name, last_name, customer_id
        FROM customer_user
        WHERE valid_id = 1
      `;
      queryParams = [];
      if (customer_company_id) {
        queryText += ` AND customer_id = $1`;
        queryParams.push(customer_company_id);
      }
    }

    queryText += ` ORDER BY last_name, first_name LIMIT 20`;

    const result = await pool.query(queryText, queryParams);
    res.json(result.rows);
  } catch (err) {
    console.error('Error searching customer users:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/agents/search — Search active agents
router.get('/agents/search', async (req, res) => {
  try {
    const { q } = req.query;
    const searchTerm = q ? `%${q}%` : '%';
    const result = await pool.query(
      `SELECT id, login, first_name, last_name
       FROM users
       WHERE valid_id = 1 AND (
         login ILIKE $1 OR
         first_name ILIKE $1 OR
         last_name ILIKE $1
       )
       ORDER BY last_name, first_name
       LIMIT 20`,
      [searchTerm]
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error searching agents:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/queues/search — Search active queues
router.get('/queues/search', async (req, res) => {
  try {
    const { q } = req.query;
    const searchTerm = q ? `%${q}%` : '%';
    const result = await pool.query(
      `SELECT id, name
       FROM queue
       WHERE valid_id = 1 AND name ILIKE $1
       ORDER BY name
       LIMIT 20`,
      [searchTerm]
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error searching queues:', err);
    res.status(500).json({ error: err.message });
  }
});

// GET /api/states/search — Search active ticket states
router.get('/states/search', async (req, res) => {
  try {
    const { q } = req.query;
    const searchTerm = q ? `%${q}%` : '%';
    const result = await pool.query(
      `SELECT id, name
       FROM ticket_state
       WHERE valid_id = 1 AND name ILIKE $1
       ORDER BY name
       LIMIT 20`,
      [searchTerm]
    );
    res.json(result.rows);
  } catch (err) {
    console.error('Error searching states:', err);
    res.status(500).json({ error: err.message });
  }
});

// Helper function to sync customer users from LDAP (OTRS API) into in-memory cache
async function syncCustomerUsers() {
  if (!process.env.OTRS_API_URL || !process.env.OTRS_API_USER) {
    console.log('[LDAP Sync] OTRS API not configured, skipping customer user sync.');
    return 0;
  }

  console.log('[LDAP Sync] Starting customer user synchronization...');
  try {
    const searchResult = await otrsRequest('POST', '/CustomerUserSearch', { Search: '*', Valid: 1 });
    const searchData = (searchResult && searchResult.Data) || searchResult;
    if (!searchData || !searchData.CustomerUserID) {
      console.log('[LDAP Sync] No customer users found to sync.');
      return 0;
    }

    let logins = searchData.CustomerUserID;
    if (!Array.isArray(logins)) {
      logins = [logins];
    }

    console.log(`[LDAP Sync] Found ${logins.length} customer users. Fetching details...`);

    const delay = ms => new Promise(resolve => setTimeout(resolve, ms));
    const newCache = [];
    // Fetch details in batches of 3 to avoid overloading the OTRS CGI server
    const batchSize = 3;
    for (let i = 0; i < logins.length; i += batchSize) {
      const batchLogins = logins.slice(i, i + batchSize);
      await Promise.all(batchLogins.map(async (login) => {
        let retries = 2;
        while (retries >= 0) {
          try {
            const getResult = await otrsRequest('POST', '/CustomerUserGet', { UserLogin: login });
            const getData = (getResult && getResult.Data) || getResult;
            if (getData && getData.CustomerUser) {
              const u = getData.CustomerUser;
              newCache.push({
                login: u.UserLogin,
                email: u.UserEmail || '',
                first_name: u.UserFirstname || '',
                last_name: u.UserLastname || '',
                customer_id: u.UserCustomerID || ''
              });
            }
            break; // Success, break retry loop
          } catch (getErr) {
            if (retries === 0) {
              console.warn(`[LDAP Sync] Failed to sync customer user ${login} after retries:`, getErr.message);
            } else {
              await delay(200); // Wait 200ms before retrying
            }
            retries--;
          }
        }
      }));
      // Add a small delay between batches
      await delay(50);
    }

    ldapCustomerUsersCache = newCache;
    console.log(`[LDAP Sync] Completed. Synced ${ldapCustomerUsersCache.length} users to in-memory cache.`);
    return ldapCustomerUsersCache.length;
  } catch (err) {
    console.error('[LDAP Sync] Error during customer user sync:', err);
    throw err;
  }
}

// POST /api/customer-users/sync — Sync customer users from LDAP
router.post('/customer-users/sync', async (req, res) => {
  try {
    const count = await syncCustomerUsers();
    res.json({ message: `Sincronizzazione completata! ${count} utenti sincronizzati.`, count });
  } catch (err) {
    res.status(500).json({ error: 'Errore durante la sincronizzazione', message: err.message });
  }
});

// Run LDAP synchronization in the background on startup (after 5 seconds)
setTimeout(() => {
  syncCustomerUsers().catch(err => console.error('Startup LDAP sync failed:', err));
}, 5000);

module.exports = router;