#!/usr/bin/env node

/**
 * Download official EN16931 and PEPPOL test samples for conformance testing
 */

import * as https from 'https';
import * as fs from 'fs';
import * as path from 'path';
import { createWriteStream } from 'fs';
import { pipeline } from 'stream/promises';
import { fileURLToPath } from 'url';

interface TestSampleSource {
  name: string;
  description: string;
  repository: string;
  branch: string;
  paths: string[];
  targetDir: string;
}

const TEST_SAMPLE_SOURCES: TestSampleSource[] = [
  {
    name: 'PEPPOL BIS 3.0 Examples',
    description: 'Official PEPPOL BIS Billing 3.0 example files',
    repository: 'OpenPEPPOL/peppol-bis-invoice-3',
    branch: 'master',
    paths: [
      'rules/examples/Allowance-example.xml',
      'rules/examples/base-example.xml',
      'rules/examples/base-negative-inv-correction.xml',
      'rules/examples/vat-category-E.xml',
      'rules/examples/vat-category-O.xml',
      'rules/examples/vat-category-S.xml',
      'rules/examples/vat-category-Z.xml',
      'rules/examples/vat-category-AE.xml',
      'rules/examples/vat-category-K.xml',
      'rules/examples/vat-category-G.xml'
    ],
    targetDir: 'peppol-bis3'
  },
  {
    name: 'CEN TC434 Test Files',
    description: 'European Committee for Standardization test files',
    repository: 'ConnectingEurope/eInvoicing-EN16931',
    branch: 'master',
    paths: [
      'ubl/examples/ubl-tc434-example1.xml',
      'ubl/examples/ubl-tc434-example2.xml',
      'ubl/examples/ubl-tc434-example3.xml',
      'ubl/examples/ubl-tc434-example4.xml',
      'ubl/examples/ubl-tc434-example5.xml',
      'ubl/examples/ubl-tc434-example6.xml',
      'ubl/examples/ubl-tc434-example7.xml',
      'ubl/examples/ubl-tc434-example8.xml',
      'ubl/examples/ubl-tc434-example9.xml',
      'cii/examples/cii-tc434-example1.xml',
      'cii/examples/cii-tc434-example2.xml',
      'cii/examples/cii-tc434-example3.xml',
      'cii/examples/cii-tc434-example4.xml',
      'cii/examples/cii-tc434-example5.xml',
      'cii/examples/cii-tc434-example6.xml',
      'cii/examples/cii-tc434-example7.xml',
      'cii/examples/cii-tc434-example8.xml',
      'cii/examples/cii-tc434-example9.xml'
    ],
    targetDir: 'cen-tc434'
  },
  {
    name: 'PEPPOL Validation Artifacts',
    description: 'PEPPOL validation test files',
    repository: 'OpenPEPPOL/peppol-bis-invoice-3',
    branch: 'master',
    paths: [
      'rules/unit-UBL/PEPPOL-EN16931-UBL.xml'
    ],
    targetDir: 'peppol-validation'
  }
];

/**
 * Download a file from GitHub
 */
async function downloadFile(
  repo: string,
  branch: string,
  filePath: string,
  targetPath: string
): Promise<void> {
  const url = `https://raw.githubusercontent.com/${repo}/${branch}/${filePath}`;
  
  return new Promise((resolve, reject) => {
    https.get(url, (response) => {
      if (response.statusCode === 404) {
        console.warn(`  ⚠️  File not found: ${filePath}`);
        resolve();
        return;
      }
      
      if (response.statusCode !== 200) {
        reject(new Error(`Failed to download ${url}: ${response.statusCode}`));
        return;
      }
      
      const dir = path.dirname(targetPath);
      if (!fs.existsSync(dir)) {
        fs.mkdirSync(dir, { recursive: true });
      }
      
      const file = createWriteStream(targetPath);
      response.pipe(file);
      
      file.on('finish', () => {
        file.close();
        console.log(`  ✅ Downloaded: ${path.basename(filePath)}`);
        resolve();
      });
      
      file.on('error', (err) => {
        fs.unlink(targetPath, () => {}); // Delete incomplete file
        reject(err);
      });
    }).on('error', reject);
  });
}

/**
 * Download test samples from a source
 */
async function downloadTestSamples(source: TestSampleSource): Promise<void> {
  console.log(`\n📦 ${source.name}`);
  console.log(`   ${source.description}`);
  console.log(`   Repository: ${source.repository}`);
  
  const baseDir = path.join('test-samples', source.targetDir);
  
  for (const filePath of source.paths) {
    const fileName = path.basename(filePath);
    const targetPath = path.join(baseDir, fileName);
    
    try {
      await downloadFile(source.repository, source.branch, filePath, targetPath);
    } catch (error) {
      console.error(`  ❌ Error downloading ${fileName}: ${error.message}`);
    }
  }
}

/**
 * Create metadata file for downloaded samples
 */
function createMetadata(sources: TestSampleSource[]): void {
  const metadata = {
    downloadDate: new Date().toISOString(),
    sources: sources.map(s => ({
      name: s.name,
      repository: s.repository,
      branch: s.branch,
      fileCount: s.paths.length
    })),
    totalFiles: sources.reduce((sum, s) => sum + s.paths.length, 0)
  };
  
  const metadataPath = path.join('test-samples', 'metadata.json');
  fs.writeFileSync(metadataPath, JSON.stringify(metadata, null, 2));
  console.log('\n📝 Created metadata.json');
}

/**
 * Main function
 */
async function main() {
  console.log('🚀 Downloading official EN16931 test samples...\n');
  
  // Create base directory
  if (!fs.existsSync('test-samples')) {
    fs.mkdirSync('test-samples');
  }
  
  // Download samples from each source
  for (const source of TEST_SAMPLE_SOURCES) {
    await downloadTestSamples(source);
  }
  
  // Create metadata file
  createMetadata(TEST_SAMPLE_SOURCES);
  
  console.log('\n✨ Test sample download complete!');
  console.log('📁 Samples saved to: test-samples/');
  
  // Count total files
  const totalFiles = TEST_SAMPLE_SOURCES.reduce((sum, s) => sum + s.paths.length, 0);
  console.log(`📊 Total files: ${totalFiles}`);
}

// Run if executed directly
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

if (import.meta.url === `file://${process.argv[1]}`) {
  main().catch(console.error);
}

export { downloadTestSamples, TEST_SAMPLE_SOURCES };