const express = require('express');
const { authenticateToken } = require('../../middleware/auth');

const router = express.Router();

// Debug: Get JTL Kontierung data for a specific JTL Umsatz (by kZahlungsabgleichUmsatz)
router.get('/jtl-kontierung/:jtlId', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { jtlId } = req.params;

    const query = `
      SELECT
        uk.data
      FROM eazybusiness.dbo.tZahlungsabgleichUmsatz z
      LEFT JOIN eazybusiness.dbo.tUmsatzKontierung uk
        ON uk.kZahlungsabgleichUmsatz = z.kZahlungsabgleichUmsatz
      WHERE z.kZahlungsabgleichUmsatz = @jtlId
    `;

    const result = await executeQuery(query, { jtlId: parseInt(jtlId, 10) });
    // Return undefined when no data found (do not lie with empty array/string)
    if (!result.recordset || result.recordset.length === 0) {
      return res.json({ data: undefined });
    }

    // If multiple rows exist, return all; otherwise single object
    const rows = result.recordset.map(r => ({ data: r.data }));
    if (rows.length === 1) {
      return res.json(rows[0]);
    }
    return res.json(rows);
  } catch (error) {
    console.error('Error fetching JTL Kontierung data:', error);
    res.status(500).json({ error: 'Failed to fetch JTL Kontierung data' });
  }
});

// Get accounting items for a specific transaction
router.get('/accounting-items/:transactionId', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { transactionId } = req.params;
    
    // Try both numeric and string format (similar to banking transactions)
    let query, params;
    const numericId = parseInt(transactionId, 10);
    
    if (!isNaN(numericId) && numericId.toString() === transactionId) {
      // It's a numeric ID - check transaction_id column
      query = `
        SELECT 
          ai.*,
          k.name as konto_name,
          bu.name as bu_name,
          bu.vst as bu_vst
        FROM fibdash.AccountingItems ai
        LEFT JOIN fibdash.Konto k ON ai.konto = k.konto
        LEFT JOIN fibdash.BU bu ON ai.bu = bu.bu
        WHERE ai.transaction_id = @transactionId
        ORDER BY ai.id
      `;
      params = { transactionId: numericId };
    } else {
      // It's a string ID - check csv_transaction_id column
      query = `
        SELECT 
          ai.*,
          k.name as konto_name,
          bu.name as bu_name,
          bu.vst as bu_vst
        FROM fibdash.AccountingItems ai
        LEFT JOIN fibdash.Konto k ON ai.konto = k.konto
        LEFT JOIN fibdash.BU bu ON ai.bu = bu.bu
        WHERE ai.csv_transaction_id = @transactionId
        ORDER BY ai.id
      `;
      params = { transactionId };
    }
    
    const result = await executeQuery(query, params);
    res.json(result.recordset);
  } catch (error) {
    console.error('Error fetching accounting items:', error);
    res.status(500).json({ error: 'Failed to fetch accounting items' });
  }
});

// Create accounting item for a transaction
router.post('/accounting-items', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { 
      transaction_id, 
      csv_transaction_id, 
      umsatz_brutto, 
      soll_haben_kz, 
      konto, 
      bu, 
      buchungsdatum, 
      rechnungsnummer, 
      buchungstext 
    } = req.body;
    
    if ((!transaction_id && !csv_transaction_id) || !umsatz_brutto || !soll_haben_kz || !konto || !buchungsdatum) {
      return res.status(400).json({ 
        error: 'Transaction ID, amount, debit/credit indicator, account, and booking date are required' 
      });
    }
    
    let insertQuery, queryParams;
    
    if (csv_transaction_id) {
      // For CSV transactions, use placeholder transaction_id
      insertQuery = `
        INSERT INTO fibdash.AccountingItems 
        (transaction_id, csv_transaction_id, umsatz_brutto, soll_haben_kz, konto, gegenkonto, bu, buchungsdatum, rechnungsnummer, buchungstext)
        OUTPUT INSERTED.*
        VALUES (-1, @csv_transaction_id, @umsatz_brutto, @soll_haben_kz, @konto, '', @bu, @buchungsdatum, @rechnungsnummer, @buchungstext)
      `;
      queryParams = {
        csv_transaction_id,
        umsatz_brutto,
        soll_haben_kz,
        konto,
        bu: bu || null,
        buchungsdatum,
        rechnungsnummer: rechnungsnummer || null,
        buchungstext: buchungstext || null
      };
    } else {
      // For regular transactions
      insertQuery = `
        INSERT INTO fibdash.AccountingItems 
        (transaction_id, csv_transaction_id, umsatz_brutto, soll_haben_kz, konto, gegenkonto, bu, buchungsdatum, rechnungsnummer, buchungstext)
        OUTPUT INSERTED.*
        VALUES (@transaction_id, NULL, @umsatz_brutto, @soll_haben_kz, @konto, '', @bu, @buchungsdatum, @rechnungsnummer, @buchungstext)
      `;
      queryParams = {
        transaction_id,
        umsatz_brutto,
        soll_haben_kz,
        konto,
        bu: bu || null,
        buchungsdatum,
        rechnungsnummer: rechnungsnummer || null,
        buchungstext: buchungstext || null
      };
    }
    
    const result = await executeQuery(insertQuery, queryParams);
    res.status(201).json(result.recordset[0]);
  } catch (error) {
    console.error('Error creating accounting item:', error);
    res.status(500).json({ error: 'Failed to create accounting item' });
  }
});

// Update accounting item
router.put('/accounting-items/:id', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { id } = req.params;
    const { umsatz_brutto, soll_haben_kz, konto, bu, rechnungsnummer, buchungstext } = req.body;
    
    if (!umsatz_brutto || !soll_haben_kz || !konto) {
      return res.status(400).json({ error: 'Amount, debit/credit indicator, and account are required' });
    }
    
    const updateQuery = `
      UPDATE fibdash.AccountingItems 
      SET umsatz_brutto = @umsatz_brutto,
          soll_haben_kz = @soll_haben_kz,
          konto = @konto,
          bu = @bu,
          rechnungsnummer = @rechnungsnummer,
          buchungstext = @buchungstext
      OUTPUT INSERTED.*
      WHERE id = @id
    `;
    
    const result = await executeQuery(updateQuery, {
      umsatz_brutto,
      soll_haben_kz,
      konto,
      bu: bu || null,
      rechnungsnummer: rechnungsnummer || null,
      buchungstext: buchungstext || null,
      id: parseInt(id, 10)
    });
    
    if (result.recordset.length === 0) {
      return res.status(404).json({ error: 'Accounting item not found' });
    }
    
    res.json(result.recordset[0]);
  } catch (error) {
    console.error('Error updating accounting item:', error);
    res.status(500).json({ error: 'Failed to update accounting item' });
  }
});

// Delete accounting item
router.delete('/accounting-items/:id', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { id } = req.params;
    
    const deleteQuery = `DELETE FROM fibdash.AccountingItems WHERE id = @id`;
    await executeQuery(deleteQuery, { id: parseInt(id, 10) });
    
    res.json({ message: 'Accounting item deleted successfully' });
  } catch (error) {
    console.error('Error deleting accounting item:', error);
    res.status(500).json({ error: 'Failed to delete accounting item' });
  }
});

// Get all Konto options
router.get('/kontos', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    
    const query = `SELECT * FROM fibdash.Konto ORDER BY konto`;
    const result = await executeQuery(query);
    
    res.json(result.recordset);
  } catch (error) {
    console.error('Error fetching kontos:', error);
    res.status(500).json({ error: 'Failed to fetch kontos' });
  }
});

// Create new Konto
router.post('/kontos', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    const { konto, name } = req.body;
    
    if (!konto || !name) {
      return res.status(400).json({ error: 'Konto and name are required' });
    }
    
    const insertQuery = `
      INSERT INTO fibdash.Konto (konto, name)
      OUTPUT INSERTED.*
      VALUES (@konto, @name)
    `;
    
    const result = await executeQuery(insertQuery, { konto, name });
    res.status(201).json(result.recordset[0]);
  } catch (error) {
    console.error('Error creating konto:', error);
    res.status(500).json({ error: 'Failed to create konto' });
  }
});

// Get all BU options
router.get('/bus', authenticateToken, async (req, res) => {
  try {
    const { executeQuery } = require('../../config/database');
    
    const query = `SELECT * FROM fibdash.BU ORDER BY bu`;
    const result = await executeQuery(query);
    
    res.json(result.recordset);
  } catch (error) {
    console.error('Error fetching BUs:', error);
    res.status(500).json({ error: 'Failed to fetch BUs' });
  }
});

module.exports = router;