import express from 'express';
import { invoiceService } from '../services/invoiceService.js';
import { authenticate, requireTenant } from '../middleware/auth.js';
import { validateRequest } from '../middleware/validation.js';
import { body, param, query } from 'express-validator';
import { logger } from '../utils/logger.js';

const router = express.Router();

// Create invoice
router.post('/',
  authenticate,
  requireTenant,
  validateRequest([
    body('subscriptionId').optional().isMongoId(),
    body('lineItems').isArray(),
    body('lineItems.*.description').notEmpty(),
    body('lineItems.*.quantity').isInt({ min: 1 }),
    body('lineItems.*.unitPrice').isFloat({ min: 0 }),
    body('dueDate').optional().isISO8601()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.createInvoice(
        req.tenantId,
        {
          ...req.body,
          customerId: req.tenant.billing?.customerId,
          customer: {
            name: req.tenant.name,
            email: req.tenant.owner.email,
            address: req.tenant.billing?.billingAddress
          }
        }
      );

      res.status(201).json({
        success: true,
        invoice
      });
    } catch (error) {
      logger.error('Create invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to create invoice'
      });
    }
  }
);

// Get invoices
router.get('/',
  authenticate,
  requireTenant,
  validateRequest([
    query('status').optional().isIn(['draft', 'open', 'paid', 'void', 'uncollectible']),
    query('startDate').optional().isISO8601(),
    query('endDate').optional().isISO8601(),
    query('limit').optional().isInt({ min: 1, max: 100 })
  ]),
  async (req, res) => {
    try {
      const invoices = await invoiceService.getInvoices(
        req.tenantId,
        req.query
      );

      res.json({
        success: true,
        invoices
      });
    } catch (error) {
      logger.error('Get invoices error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to get invoices'
      });
    }
  }
);

// Get unpaid invoices
router.get('/unpaid',
  authenticate,
  requireTenant,
  async (req, res) => {
    try {
      const invoices = await invoiceService.getUnpaidInvoices(req.tenantId);

      res.json({
        success: true,
        invoices,
        totalDue: invoices.reduce((sum, inv) => sum + inv.amountDue, 0)
      });
    } catch (error) {
      logger.error('Get unpaid invoices error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to get unpaid invoices'
      });
    }
  }
);

// Get overdue invoices
router.get('/overdue',
  authenticate,
  requireTenant,
  async (req, res) => {
    try {
      const invoices = await invoiceService.getOverdueInvoices(req.tenantId);

      res.json({
        success: true,
        invoices,
        totalOverdue: invoices.reduce((sum, inv) => sum + inv.amountDue, 0)
      });
    } catch (error) {
      logger.error('Get overdue invoices error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to get overdue invoices'
      });
    }
  }
);

// Get invoice by ID
router.get('/:id',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.getInvoice(
        req.tenantId,
        req.params.id
      );

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

      res.json({
        success: true,
        invoice
      });
    } catch (error) {
      logger.error('Get invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to get invoice'
      });
    }
  }
);

// Update invoice (draft only)
router.patch('/:id',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId(),
    body('lineItems').optional().isArray(),
    body('dueDate').optional().isISO8601()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.updateInvoice(
        req.tenantId,
        req.params.id,
        req.body
      );

      res.json({
        success: true,
        invoice
      });
    } catch (error) {
      logger.error('Update invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to update invoice'
      });
    }
  }
);

// Finalize invoice
router.post('/:id/finalize',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.finalizeInvoice(
        req.tenantId,
        req.params.id
      );

      res.json({
        success: true,
        invoice,
        message: 'Invoice finalized and sent'
      });
    } catch (error) {
      logger.error('Finalize invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to finalize invoice'
      });
    }
  }
);

// Pay invoice
router.post('/:id/pay',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId(),
    body('paymentMethodId').optional().isString()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.payInvoice(
        req.tenantId,
        req.params.id,
        {
          paymentMethodId: req.body.paymentMethodId
        }
      );

      res.json({
        success: true,
        invoice,
        message: 'Invoice paid successfully'
      });
    } catch (error) {
      logger.error('Pay invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to pay invoice'
      });
    }
  }
);

// Void invoice
router.post('/:id/void',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId(),
    body('reason').notEmpty()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.voidInvoice(
        req.tenantId,
        req.params.id,
        req.body.reason
      );

      res.json({
        success: true,
        invoice,
        message: 'Invoice voided'
      });
    } catch (error) {
      logger.error('Void invoice error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to void invoice'
      });
    }
  }
);

// Download invoice PDF
router.get('/:id/pdf',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId()
  ]),
  async (req, res) => {
    try {
      const invoice = await invoiceService.getInvoice(
        req.tenantId,
        req.params.id
      );

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

      // Generate PDF if not exists
      if (!invoice.pdfUrl) {
        await invoiceService.generatePDF(invoice);
      }

      // In production, redirect to cloud storage URL
      res.redirect(invoice.pdfUrl);
    } catch (error) {
      logger.error('Download invoice PDF error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to download invoice'
      });
    }
  }
);

// Send invoice reminder
router.post('/:id/remind',
  authenticate,
  requireTenant,
  validateRequest([
    param('id').isMongoId()
  ]),
  async (req, res) => {
    try {
      await invoiceService.sendInvoiceReminder(
        req.tenantId,
        req.params.id
      );

      res.json({
        success: true,
        message: 'Invoice reminder sent'
      });
    } catch (error) {
      logger.error('Send reminder error:', error);
      res.status(500).json({
        success: false,
        error: 'Failed to send reminder'
      });
    }
  }
);

export default router;