const http = require('http');
const fs = require('fs');
const path = require('path');
const xlsx = require('xlsx');

// Import the app from server.js by refactoring or starting server
// Let's create an automated test against the server
async function runTests() {
  const PORT = 3055;
  process.env.PORT = PORT;
  
  console.log('--- Starting Server for Integration Tests ---');
  require('./server.js');

  // Wait 1s for server to listen
  await new Promise(r => setTimeout(r, 1000));

  console.log('\n--- Test 1: GET /api/files ---');
  const getFilesRes = await fetch(`http://localhost:${PORT}/api/files`);
  const getFilesData = await getFilesRes.json();
  console.log('GET /api/files status:', getFilesRes.status);
  console.log('Initial files count:', getFilesData.files ? getFilesData.files.length : 0);

  console.log('\n--- Test 2: Invalid File Upload Handling ---');
  const invalidBlob = new Blob(['This is not an excel file'], { type: 'text/plain' });
  const invalidForm = new FormData();
  invalidForm.append('file', invalidBlob, 'test_invalid.txt');

  const invalidRes = await fetch(`http://localhost:${PORT}/api/upload`, {
    method: 'POST',
    body: invalidForm
  });
  const invalidData = await invalidRes.json();
  console.log('Invalid upload status:', invalidRes.status, '(Expected 400)');
  console.log('Invalid upload error message:', invalidData.error);
  if (invalidRes.status !== 400) {
    throw new Error('Test 2 failed: server did not reject invalid file');
  }

  console.log('\n--- Test 3: Upload Real Multi-Sheet Excel File ---');
  const sampleFilePath = path.join(__dirname, 'sample_company_data.xlsx');
  const fileBuffer = fs.readFileSync(sampleFilePath);
  const sampleBlob = new Blob([fileBuffer], {
    type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
  });
  const validForm = new FormData();
  validForm.append('file', sampleBlob, 'sample_company_data.xlsx');

  const uploadRes = await fetch(`http://localhost:${PORT}/api/upload`, {
    method: 'POST',
    body: validForm
  });
  const uploadData = await uploadRes.json();
  console.log('Upload status:', uploadRes.status);
  console.log('Uploaded file record:', uploadData.file);
  if (!uploadData.success || !uploadData.file) {
    throw new Error('Test 3 failed: upload was unsuccessful');
  }
  const uploadedFileId = uploadData.file.id;

  console.log('\n--- Test 4: Verify Worksheet List ---');
  const fileInfoRes = await fetch(`http://localhost:${PORT}/api/files/${uploadedFileId}`);
  const fileInfo = await fileInfoRes.json();
  console.log('File sheets detected:', fileInfo.sheetNames);
  if (!fileInfo.sheetNames.includes('Employees') || !fileInfo.sheetNames.includes('Quarterly Sales')) {
    throw new Error('Test 4 failed: sheets not properly detected');
  }

  console.log('\n--- Test 5: Fetch Sheet 1 Data ("Employees") ---');
  const sheet1Res = await fetch(`http://localhost:${PORT}/api/files/${uploadedFileId}/sheet?name=Employees`);
  const sheet1Data = await sheet1Res.json();
  console.log('Sheet 1 name:', sheet1Data.sheetName);
  console.log('Sheet 1 dimensions:', `${sheet1Data.totalRows} rows × ${sheet1Data.totalCols} cols`);
  console.log('Sheet 1 header row:', sheet1Data.rows[0]);
  console.log('Sheet 1 sample row:', sheet1Data.rows[1]);
  if (sheet1Data.totalRows !== 9 || sheet1Data.totalCols !== 7) {
    throw new Error(`Test 5 failed: unexpected row/col count (${sheet1Data.totalRows}x${sheet1Data.totalCols})`);
  }

  console.log('\n--- Test 6: Fetch Sheet 2 Data ("Quarterly Sales") ---');
  const sheet2Res = await fetch(`http://localhost:${PORT}/api/files/${uploadedFileId}/sheet?name=Quarterly%20Sales`);
  const sheet2Data = await sheet2Res.json();
  console.log('Sheet 2 name:', sheet2Data.sheetName);
  console.log('Sheet 2 dimensions:', `${sheet2Data.totalRows} rows × ${sheet2Data.totalCols} cols`);
  console.log('Sheet 2 header row:', sheet2Data.rows[0]);
  if (sheet2Data.totalRows !== 5 || sheet2Data.totalCols !== 7) {
    throw new Error('Test 6 failed: Sheet 2 data mismatch');
  }

  console.log('\n--- Test 7: Download Original File & Verify Integrity ---');
  const downloadRes = await fetch(`http://localhost:${PORT}/api/files/${uploadedFileId}/download`);
  console.log('Download status:', downloadRes.status);
  console.log('Download Content-Disposition:', downloadRes.headers.get('content-disposition'));
  const downloadedArrayBuffer = await downloadRes.arrayBuffer();
  const downloadedWb = xlsx.read(Buffer.from(downloadedArrayBuffer));
  console.log('Downloaded workbook sheets:', downloadedWb.SheetNames);
  if (downloadedWb.SheetNames.length !== 2 || !downloadedWb.SheetNames.includes('Employees')) {
    throw new Error('Test 7 failed: Downloaded file corrupted or incomplete');
  }

  console.log('\n--- Test 8: Upload and Parse Legacy .xls File ---');
  const legacyBuf = fs.readFileSync(path.join(__dirname, 'sample_legacy.xls'));
  const legacyForm = new FormData();
  legacyForm.append('file', new Blob([legacyBuf]), 'sample_legacy.xls');
  const xlsUploadRes = await fetch(`http://localhost:${PORT}/api/upload`, {
    method: 'POST',
    body: legacyForm
  });
  const xlsUploadData = await xlsUploadRes.json();
  console.log('Legacy .xls upload status:', xlsUploadRes.status);
  console.log('Legacy .xls file info:', xlsUploadData.file);
  if (xlsUploadRes.status !== 200 || !xlsUploadData.success) {
    throw new Error('Test 8 failed: .xls upload failed');
  }
  const xlsSheetRes = await fetch(`http://localhost:${PORT}/api/files/${xlsUploadData.file.id}/sheet`);
  const xlsSheetData = await xlsSheetRes.json();
  console.log('Legacy .xls sheet data:', xlsSheetData.rows);
  if (xlsSheetData.rows.length !== 2 || xlsSheetData.rows[1][1] !== 'Widget') {
    throw new Error('Test 8 failed: .xls sheet parsing mismatch');
  }

  console.log('\n=========================================');
  console.log('ALL WORKFLOW INTEGRATION TESTS PASSED!');
  console.log('=========================================\n');
  process.exit(0);
}

runTests().catch(err => {
  console.error('Test run failed:', err);
  process.exit(1);
});