import express from 'express';
import dotenv from 'dotenv';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { getPool } from '../utils/db.js';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

dotenv.config({ path: path.join(__dirname, "../../.env") });

const router = express.Router();

// Phase 6.2: template edits require templates_write. Reads pass through.
import { requirePermission } from '../../shared/auth/middleware.js';
router.use((req, res, next) => {
  if (req.method === 'GET' || req.method === 'HEAD' || req.method === 'OPTIONS') return next();
  return requirePermission('templates_write')(req, res, next);
});

// Get all templates
router.get('/', async (req, res) => {
  try {
    const pool = getPool();
    if (!pool) {
      throw new Error('Database pool not initialized');
    }
    
    const result = await pool.query(`
      SELECT * FROM templates 
      ORDER BY company ASC, product_type ASC
    `);
    res.json(result.rows);
  } catch (error) {
    console.error('Error fetching templates:', error);
    res.status(500).json({ 
      error: 'Failed to fetch templates',
      details: error instanceof Error ? error.message : 'Unknown error'
    });
  }
});

// Get template by company and product type
router.get('/:company/:productType', async (req, res) => {
  try {
    const { company, productType } = req.params;
    const pool = getPool();
    if (!pool) {
      throw new Error('Database pool not initialized');
    }
    
    const result = await pool.query(`
      SELECT * FROM templates 
      WHERE company = $1 AND product_type = $2
    `, [company, productType]);

    if (result.rows.length === 0) {
      return res.status(404).json({ error: 'Template not found' });
    }

    res.json(result.rows[0]);
  } catch (error) {
    console.error('Error fetching template:', error);
    res.status(500).json({ 
      error: 'Failed to fetch template',
      details: error instanceof Error ? error.message : 'Unknown error'
    });
  }
});

// Create new template
router.post('/', async (req, res) => {
  try {
    const {
      company,
      product_type,
      supplier,
      msrp,
      cost_each,
      qty_per_unit,
      case_qty,
      hts_code,
      description,
      weight,
      length,
      width,
      height,
      tax_cat,
      size_cat,
      categories,
      ship_restrictions
    } = req.body;

    // Validate required fields
    if (!company || !product_type) {
      return res.status(400).json({ error: 'Company and Product Type are required' });
    }

    const pool = getPool();
    if (!pool) {
      throw new Error('Database pool not initialized');
    }
    
    const result = await pool.query(`
      INSERT INTO templates (
        company,
        product_type,
        supplier,
        msrp,
        cost_each,
        qty_per_unit,
        case_qty,
        hts_code,
        description,
        weight,
        length,
        width,
        height,
        tax_cat,
        size_cat,
        categories,
        ship_restrictions
      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17)
      RETURNING *
    `, [
      company,
      product_type,
      supplier,
      msrp,
      cost_each,
      qty_per_unit,
      case_qty,
      hts_code,
      description,
      weight,
      length,
      width,
      height,
      tax_cat,
      size_cat,
      categories,
      ship_restrictions
    ]);

    res.status(201).json(result.rows[0]);
  } catch (error) {
    console.error('Error creating template:', error);
    // Check for unique constraint violation (PostgreSQL error code 23505)
    if (error?.code === '23505') {
      return res.status(409).json({
        error: 'A template already exists for this company and product type combination. Please edit the existing template instead.',
      });
    }
    res.status(500).json({ 
      error: 'Failed to create template',
      details: error instanceof Error ? error.message : 'Unknown error'
    });
  }
});

// Update template
router.put('/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const {
      company,
      product_type,
      supplier,
      msrp,
      cost_each,
      qty_per_unit,
      case_qty,
      hts_code,
      description,
      weight,
      length,
      width,
      height,
      tax_cat,
      size_cat,
      categories,
      ship_restrictions
    } = req.body;

    // Validate required fields
    if (!company || !product_type) {
      return res.status(400).json({ error: 'Company and Product Type are required' });
    }

    const pool = getPool();
    if (!pool) {
      throw new Error('Database pool not initialized');
    }
    
    const result = await pool.query(`
      UPDATE templates 
      SET 
        company = $1,
        product_type = $2,
        supplier = $3,
        msrp = $4,
        cost_each = $5,
        qty_per_unit = $6,
        case_qty = $7,
        hts_code = $8,
        description = $9,
        weight = $10,
        length = $11,
        width = $12,
        height = $13,
        tax_cat = $14,
        size_cat = $15,
        categories = $16,
        ship_restrictions = $17
      WHERE id = $18
      RETURNING *
    `, [
      company,
      product_type,
      supplier,
      msrp,
      cost_each,
      qty_per_unit,
      case_qty,
      hts_code,
      description,
      weight,
      length,
      width,
      height,
      tax_cat,
      size_cat,
      categories,
      ship_restrictions,
      id
    ]);

    if (result.rows.length === 0) {
      return res.status(404).json({ error: 'Template not found' });
    }

    res.json(result.rows[0]);
  } catch (error) {
    console.error('Error updating template:', error);
    // Check for unique constraint violation (PostgreSQL error code 23505)
    if (error?.code === '23505') {
      return res.status(409).json({
        error: 'A template already exists for this company and product type combination. Please edit the existing template instead.',
      });
    }
    res.status(500).json({ 
      error: 'Failed to update template',
      details: error instanceof Error ? error.message : 'Unknown error'
    });
  }
});

// Delete template
router.delete('/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const pool = getPool();
    if (!pool) {
      throw new Error('Database pool not initialized');
    }
    
    const result = await pool.query('DELETE FROM templates WHERE id = $1 RETURNING *', [id]);

    if (result.rows.length === 0) {
      return res.status(404).json({ error: 'Template not found' });
    }

    res.json({ message: 'Template deleted successfully' });
  } catch (error) {
    console.error('Error deleting template:', error);
    res.status(500).json({ 
      error: 'Failed to delete template',
      details: error instanceof Error ? error.message : 'Unknown error'
    });
  }
});

// Error handling middleware
router.use((err, req, res, next) => {
  console.error('Template route error:', err);
  res.status(500).json({ 
    error: 'Internal server error',
    details: err.message
  });
});

export default router;