const express = require('express');
const router = express.Router();
const { invoiceRepository, paymentRepository } = require('../repositories');

/**
 * GET /api/plugins/financials/invoices
 * Get all invoices for a site or unit
 */
router.get('/', async (req, res) => {
  try {
    const { site_id, unit_id, status, invoice_type } = req.query;

    if (!site_id) {
      return res.status(400).json({
        success: false,
        error: 'site_id query parameter is required'
      });
    }

    let invoices;

    // Filter by unit_id if provided
    if (unit_id) {
      invoices = await invoiceRepository.findByUnitId(unit_id);
    } else {
      invoices = await invoiceRepository.findBySiteId(site_id);
    }

    // Filter by status if provided
    if (status) {
      invoices = invoices.filter(inv => inv.status === status);
    }

    // Filter by invoice_type if provided
    if (invoice_type) {
      invoices = invoices.filter(inv => inv.invoice_type === invoice_type);
    }

    res.json({
      success: true,
      data: invoices,
      message: 'Invoices retrieved successfully'
    });
  } catch (error) {
    console.error('Failed to get invoices:', error);
    res.status(500).json({
      success: false,
      error: 'Failed to retrieve invoices',
      message: error.message
    });
  }
});

/**
 * GET /api/plugins/financials/invoices/:id
 * Get invoice by ID
 */
router.get('/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const { site_id } = req.query;

    if (!site_id) {
      return res.status(400).json({
        success: false,
        error: 'site_id is required'
      });
    }

    const invoice = await invoiceRepository.findById(id);

    if (!invoice) {
      return res.status(404).json({
        success: false,
        error: 'Invoice not found'
      });
    }

    // Verify invoice belongs to site
    if (invoice.site_id !== site_id) {
      return res.status(403).json({
        success: false,
        error: 'Access denied'
      });
    }

    res.json({
      success: true,
      data: invoice,
      message: 'Invoice details retrieved successfully'
    });
  } catch (error) {
    console.error('Failed to get invoice:', error);
    res.status(500).json({
      success: false,
      error: 'Failed to retrieve invoice',
      message: error.message
    });
  }
});

/**
 * POST /api/plugins/financials/invoices
 * Create a new invoice
 */
router.post('/', async (req, res) => {
  try {
    const { site_id, unit_id, invoice_number, invoice_type, description, amount, due_date, work_order_id, notes, created_by } = req.body;

    if (!site_id || !unit_id || !invoice_type || !description || !amount || !due_date) {
      return res.status(400).json({
        success: false,
        error: 'Missing required fields',
        message: 'Site ID, unit ID, invoice type, description, amount, and due date are required'
      });
    }

    const invoice = await invoiceRepository.createInvoice({
      site_id,
      unit_id,
      invoice_number,
      invoice_type,
      description,
      amount,
      due_date,
      work_order_id,
      notes,
      created_by: created_by || req.user?.id || 'system'
    });

    res.status(201).json({
      success: true,
      data: invoice,
      message: 'Invoice created successfully'
    });
  } catch (error) {
    console.error('Failed to create invoice:', error);
    
    if (error.message.includes('already exists')) {
      return res.status(409).json({
        success: false,
        error: 'Invoice number already exists',
        message: error.message
      });
    }

    res.status(500).json({
      success: false,
      error: 'Failed to create invoice',
      message: error.message
    });
  }
});

/**
 * PUT /api/plugins/financials/invoices/:id/pay
 * Mark invoice as paid
 */
router.put('/:id/pay', async (req, res) => {
  try {
    const { id } = req.params;
    const { payment_date, payment_method, payment_reference } = req.body;
    const { site_id } = req.query;

    if (!site_id) {
      return res.status(400).json({
        success: false,
        error: 'site_id is required'
      });
    }

    // Get invoice first to verify it exists
    const invoice = await invoiceRepository.findById(id);

    if (!invoice) {
      return res.status(404).json({
        success: false,
        error: 'Invoice not found'
      });
    }

    if (invoice.site_id !== site_id) {
      return res.status(403).json({
        success: false,
        error: 'Access denied'
      });
    }

    const updatedInvoice = await invoiceRepository.markAsPaid(id, {
      payment_date,
      payment_method,
      payment_reference
    });

    res.json({
      success: true,
      data: updatedInvoice,
      message: 'Invoice marked as paid successfully'
    });
  } catch (error) {
    console.error('Failed to mark invoice as paid:', error);
    res.status(500).json({
      success: false,
      error: 'Failed to mark invoice as paid',
      message: error.message
    });
  }
});

/**
 * PUT /api/plugins/financials/invoices/:id
 * Update invoice
 */
router.put('/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const { site_id, description, amount, due_date, status, notes } = req.body;

    if (!site_id) {
      return res.status(400).json({
        success: false,
        error: 'site_id is required'
      });
    }

    // Get invoice first
    const invoice = await invoiceRepository.findById(id);

    if (!invoice) {
      return res.status(404).json({
        success: false,
        error: 'Invoice not found'
      });
    }

    if (invoice.site_id !== site_id) {
      return res.status(403).json({
        success: false,
        error: 'Access denied'
      });
    }

    const updatedInvoice = await invoiceRepository.updateById(id, {
      description,
      amount,
      due_date,
      status,
      notes,
      updated_at: new Date().toISOString()
    });

    res.json({
      success: true,
      data: updatedInvoice,
      message: 'Invoice updated successfully'
    });
  } catch (error) {
    console.error('Failed to update invoice:', error);
    res.status(500).json({
      success: false,
      error: 'Failed to update invoice',
      message: error.message
    });
  }
});

/**
 * GET /api/plugins/financials/invoices/overdue
 * Get overdue invoices
 */
router.get('/overdue', async (req, res) => {
  try {
    const { site_id } = req.query;

    if (!site_id) {
      return res.status(400).json({
        success: false,
        error: 'site_id is required'
      });
    }

    const overdueInvoices = await invoiceRepository.findOverdue(site_id);

    res.json({
      success: true,
      data: overdueInvoices,
      message: 'Overdue invoices retrieved successfully'
    });
  } catch (error) {
    console.error('Failed to get overdue invoices:', error);
    res.status(500).json({
      success: false,
      error: 'Failed to retrieve overdue invoices',
      message: error.message
    });
  }
});

module.exports = router;