import { expect, tap } from '@git.zone/tstest/tapbundle';
import { promises as fs } from 'fs';
import * as path from 'path';
import { CorpusLoader } from '../../helpers/corpus.loader.js';
import { PerformanceTracker } from '../../helpers/performance.tracker.js';

tap.test('CONV-01: Format Conversion - should convert between invoice formats', async () => {
  // Test conversion between CII and UBL using paired files
  const ciiFiles = await CorpusLoader.getFiles('CII_XMLRECHNUNG');
  const ublFiles = await CorpusLoader.getFiles('UBL_XMLRECHNUNG');
  
  // Find paired files (same base name)
  const pairs: Array<{cii: string, ubl: string, name: string}> = [];
  
  for (const ciiFile of ciiFiles) {
    const baseName = path.basename(ciiFile).replace('.cii.xml', '');
    const matchingUbl = ublFiles.find(ubl => 
      path.basename(ubl).startsWith(baseName) && ubl.endsWith('.ubl.xml')
    );
    
    if (matchingUbl) {
      pairs.push({ cii: ciiFile, ubl: matchingUbl, name: baseName });
    }
  }
  
  console.log(`Found ${pairs.length} CII/UBL pairs for conversion testing`);

  const { EInvoice } = await import('../../../ts/index.js');
  
  let successCount = 0;
  const conversionIssues: string[] = [];
  
  for (const pair of pairs.slice(0, 5)) { // Test first 5 pairs
    try {
      // Load CII invoice
      const ciiBuffer = await fs.readFile(pair.cii, 'utf-8');
      const ciiInvoice = await EInvoice.fromXml(ciiBuffer);
      
      // Convert to UBL
      const { result: ublXml, metric } = await PerformanceTracker.track(
        'cii-to-ubl-conversion',
        async () => ciiInvoice.exportXml('ubl' as any),
        { file: pair.name }
      );
      
      expect(ublXml).toBeTruthy();
      expect(ublXml).toContain('xmlns:cbc=');
      expect(ublXml).toContain('xmlns:cac=');
      
      // Load the converted UBL back
      const convertedInvoice = await EInvoice.fromXml(ublXml);
      
      // Verify key fields are preserved
      verifyFieldMapping(ciiInvoice, convertedInvoice, pair.name);
      
      successCount++;
      console.log(`✓ ${pair.name}: CII→UBL conversion successful (${metric.duration.toFixed(2)}ms)`);
      
    } catch (error) {
      const issue = `${pair.name}: ${error.message}`;
      conversionIssues.push(issue);
      console.log(`✗ ${issue}`);
    }
  }
  
  console.log(`\nCII→UBL Conversion Summary: ${successCount}/${Math.min(pairs.length, 5)} successful`);
  if (conversionIssues.length > 0) {
    console.log('Issues:', conversionIssues.slice(0, 3));
  }

  // Performance summary
  const perfSummary = await PerformanceTracker.getSummary('cii-to-ubl-conversion');
  if (perfSummary) {
    console.log(`\nCII→UBL Conversion Performance:`);
    console.log(`  Average: ${perfSummary.average.toFixed(2)}ms`);
    console.log(`  P95: ${perfSummary.p95.toFixed(2)}ms`);
  }

  expect(successCount).toBeGreaterThan(0);
});

tap.test('CONV-01: UBL to CII Conversion - should convert UBL invoices to CII format', async () => {
  const { EInvoice } = await import('../../../ts/index.js');
  
  const ublFiles = await CorpusLoader.getFiles('UBL_XMLRECHNUNG');
  const testFiles = ublFiles.filter(f => f.endsWith('.xml')).slice(0, 3);
  
  console.log(`Testing UBL to CII conversion with ${testFiles.length} files`);
  
  let successCount = 0;
  let skipCount = 0;
  
  for (const filePath of testFiles) {
    const fileName = path.basename(filePath);
    
    try {
      const ublContent = await fs.readFile(filePath, 'utf-8');
      const ublInvoice = await EInvoice.fromXml(ublContent);
      
      // Skip if detected as XRechnung (might have special requirements)
      const format = ublInvoice.getFormat ? ublInvoice.getFormat() : 'unknown';
      if (format.toString().toLowerCase().includes('xrechnung')) {
        console.log(`○ ${fileName}: Skipping XRechnung-specific file`);
        skipCount++;
        continue;
      }
      
      // Convert to CII (Factur-X)
      const { result: ciiXml, metric } = await PerformanceTracker.track(
        'ubl-to-cii-conversion',
        async () => ublInvoice.exportXml('facturx' as any),
        { file: fileName }
      );
      
      expect(ciiXml).toBeTruthy();
      expect(ciiXml).toContain('CrossIndustryInvoice');
      expect(ciiXml).toContain('ExchangedDocument');
      
      // Verify round-trip
      const ciiInvoice = await EInvoice.fromXml(ciiXml);
      expect(ciiInvoice.invoiceId).toEqual(ublInvoice.invoiceId);
      
      successCount++;
      console.log(`✓ ${fileName}: UBL→CII conversion successful (${metric.duration.toFixed(2)}ms)`);
      
    } catch (error) {
      console.log(`✗ ${fileName}: Conversion failed - ${error.message}`);
    }
  }

  console.log(`\nUBL→CII Conversion Summary: ${successCount} successful, ${skipCount} skipped`);

  // Performance summary
  const perfSummary = await PerformanceTracker.getSummary('ubl-to-cii-conversion');
  if (perfSummary) {
    console.log(`\nUBL→CII Conversion Performance:`);
    console.log(`  Average: ${perfSummary.average.toFixed(2)}ms`);
    console.log(`  P95: ${perfSummary.p95.toFixed(2)}ms`);
  }

  expect(successCount + skipCount).toBeGreaterThan(0);
});

tap.test('CONV-01: ZUGFeRD to XRechnung Conversion - should convert ZUGFeRD PDFs to XRechnung', async () => {
  const { EInvoice } = await import('../../../ts/index.js');
  
  const zugferdPdfs = await CorpusLoader.getFiles('ZUGFERD_V2_CORRECT');
  const pdfFiles = zugferdPdfs.filter(f => f.endsWith('.pdf')).slice(0, 3);
  
  console.log(`Testing ZUGFeRD to XRechnung conversion with ${pdfFiles.length} PDFs`);
  
  let tested = 0;
  let successful = 0;
  
  for (const filePath of pdfFiles) {
    const fileName = path.basename(filePath);
    
    try {
      // Extract from PDF
      const pdfBuffer = await fs.readFile(filePath);
      const zugferdInvoice = await EInvoice.fromPdf(pdfBuffer);
      
      // Convert to XRechnung
      const { result: xrechnungXml, metric } = await PerformanceTracker.track(
        'zugferd-to-xrechnung-conversion',
        async () => zugferdInvoice.exportXml('xrechnung' as any),
        { file: fileName }
      );
      
      expect(xrechnungXml).toBeTruthy();
      
      // XRechnung should be UBL format with specific extensions
      if (xrechnungXml.includes('Invoice xmlns')) {
        expect(xrechnungXml).toContain('CustomizationID');
        expect(xrechnungXml).toContain('urn:cen.eu:en16931');
      }
      
      tested++;
      successful++;
      console.log(`✓ ${fileName}: ZUGFeRD→XRechnung conversion successful (${metric.duration.toFixed(2)}ms)`);
      
    } catch (error) {
      tested++;
      console.log(`○ ${fileName}: Conversion not available - ${error.message}`);
    }
  }
  
  console.log(`\nZUGFeRD→XRechnung Conversion Summary: ${successful}/${tested} successful`);
  
  if (successful === 0 && tested > 0) {
    console.log('Note: ZUGFeRD to XRechnung conversion may need implementation');
  }

  // Performance summary
  const perfSummary = await PerformanceTracker.getSummary('zugferd-to-xrechnung-conversion');
  if (perfSummary) {
    console.log(`\nZUGFeRD→XRechnung Conversion Performance:`);
    console.log(`  Average: ${perfSummary.average.toFixed(2)}ms`);
    console.log(`  P95: ${perfSummary.p95.toFixed(2)}ms`);
  }

  expect(tested).toBeGreaterThan(0);
});

tap.test('CONV-01: Data Preservation During Conversion - should preserve invoice data across formats', async () => {
  const { EInvoice } = await import('../../../ts/index.js');
  
  // Create a test invoice with comprehensive data
  const testInvoice = new EInvoice();
  testInvoice.id = 'DATA-PRESERVATION-TEST';
  testInvoice.invoiceId = 'INV-2024-001';
  testInvoice.date = Date.now();
  testInvoice.currency = 'EUR';
  
  testInvoice.from = {
    name: 'Test Seller GmbH',
    type: 'company',
    description: 'Test seller company',
    address: {
      streetName: 'Musterstraße',
      houseNumber: '123',
      city: 'Berlin',
      country: 'Germany',
      postalCode: '10115'
    },
    status: 'active',
    foundedDate: { year: 2020, month: 1, day: 1 },
    registrationDetails: {
      vatId: 'DE123456789',
      registrationId: 'HRB 12345',
      registrationName: 'Handelsregister Berlin'
    }
  };
  
  testInvoice.to = {
    name: 'Test Buyer Ltd',
    type: 'company',
    description: 'Test buyer company',
    address: {
      streetName: 'Example Street',
      houseNumber: '456',
      city: 'London',
      country: 'United Kingdom',
      postalCode: 'SW1A 1AA'
    },
    status: 'active',
    foundedDate: { year: 2019, month: 6, day: 15 },
    registrationDetails: {
      vatId: 'GB987654321',
      registrationId: 'Companies House 87654321',
      registrationName: 'Companies House'
    }
  };
  
  testInvoice.items = [
    {
      position: 1,
      name: 'Professional Service',
      articleNumber: 'SERV-001',
      unitType: 'HUR',
      unitQuantity: 8,
      unitNetPrice: 150,
      vatPercentage: 19
    },
    {
      position: 2,
      name: 'Software License',
      articleNumber: 'SOFT-001',
      unitType: 'EA',
      unitQuantity: 1,
      unitNetPrice: 500,
      vatPercentage: 19
    }
  ];

  // Test conversions and check for data preservation
  const conversions: Array<{from: string, to: string}> = [
    { from: 'facturx', to: 'ubl' },
    { from: 'facturx', to: 'xrechnung' }
  ];
  
  for (const conversion of conversions) {
    console.log(`\nTesting ${conversion.from} → ${conversion.to} data preservation:`);
    
    try {
      // Generate source XML
      const sourceXml = await testInvoice.exportXml(conversion.from as any);
      await testInvoice.loadXml(sourceXml);
      
      // Convert to target format
      const { result: convertedXml, metric } = await PerformanceTracker.track(
        'data-preservation-conversion',
        async () => testInvoice.exportXml(conversion.to as any),
        { conversion: `${conversion.from}-to-${conversion.to}` }
      );
      
      const convertedInvoice = await EInvoice.fromXml(convertedXml);
      
      // Check for data preservation
      const issues = checkDataPreservation(testInvoice, convertedInvoice);
      
      if (issues.length === 0) {
        console.log(`✓ All critical data preserved (${metric.duration.toFixed(2)}ms)`);
      } else {
        console.log(`⚠ Data preservation issues found:`);
        issues.forEach(issue => console.log(`  - ${issue}`));
      }
      
      // Core fields should always be preserved
      expect(convertedInvoice.invoiceId).toEqual(testInvoice.invoiceId);
      expect(convertedInvoice.from.name).toEqual(testInvoice.from.name);
      expect(convertedInvoice.to.name).toEqual(testInvoice.to.name);
      
    } catch (error) {
      console.log(`✗ Conversion failed: ${error.message}`);
    }
  }
});

tap.test('CONV-01: Conversion Performance Benchmarks - should meet conversion performance targets', async () => {
  console.log('\nConversion Performance Benchmark Summary:');
  
  const conversionOperations = [
    'cii-to-ubl-conversion',
    'ubl-to-cii-conversion',
    'zugferd-to-xrechnung-conversion'
  ];

  const benchmarkResults: { operation: string; metrics: any }[] = [];

  for (const operation of conversionOperations) {
    const summary = await PerformanceTracker.getSummary(operation);
    if (summary) {
      benchmarkResults.push({ operation, metrics: summary });
      console.log(`\n${operation}:`);
      console.log(`  Average: ${summary.average.toFixed(2)}ms`);
      console.log(`  P95: ${summary.p95.toFixed(2)}ms`);
      console.log(`  Count: ${summary.min !== undefined ? 'Available' : 'No data'}`);
    }
  }

  if (benchmarkResults.length > 0) {
    const overallAverage = benchmarkResults.reduce((sum, result) => 
      sum + result.metrics.average, 0) / benchmarkResults.length;
    
    console.log(`\nOverall Conversion Performance:`);
    console.log(`  Average across operations: ${overallAverage.toFixed(2)}ms`);
    
    // Performance targets
    expect(overallAverage).toBeLessThan(1000); // Conversions should be under 1 second on average
    
    benchmarkResults.forEach(result => {
      expect(result.metrics.p95).toBeLessThan(2000); // P95 should be under 2 seconds
    });

    console.log(`✓ All conversion performance benchmarks met`);
  } else {
    console.log('No conversion performance data available');
  }
});

// Helper function to verify field mapping between invoices
function verifyFieldMapping(source: EInvoice, converted: EInvoice, testName: string): void {
  const criticalFields = [
    { field: 'invoiceId', name: 'Invoice ID' },
    { field: 'currency', name: 'Currency' }
  ];
  
  for (const check of criticalFields) {
    const sourceVal = source[check.field as keyof EInvoice];
    const convertedVal = converted[check.field as keyof EInvoice];
    
    if (sourceVal !== convertedVal) {
      console.log(`  ⚠ ${check.name} mismatch: ${sourceVal} → ${convertedVal}`);
    }
  }
  
  // Check seller/buyer names
  if (source.from?.name !== converted.from?.name) {
    console.log(`  ⚠ Seller name mismatch: ${source.from?.name} → ${converted.from?.name}`);
  }
  
  if (source.to?.name !== converted.to?.name) {
    console.log(`  ⚠ Buyer name mismatch: ${source.to?.name} → ${converted.to?.name}`);
  }
  
  // Check items count
  if (source.items?.length !== converted.items?.length) {
    console.log(`  ⚠ Items count mismatch: ${source.items?.length} → ${converted.items?.length}`);
  }
}

// Helper function to check data preservation
function checkDataPreservation(source: EInvoice, converted: EInvoice): string[] {
  const issues: string[] = [];
  
  // Check basic fields
  if (source.invoiceId !== converted.invoiceId) {
    issues.push(`Invoice ID changed: ${source.invoiceId} → ${converted.invoiceId}`);
  }
  
  if (source.currency !== converted.currency) {
    issues.push(`Currency changed: ${source.currency} → ${converted.currency}`);
  }
  
  // Check party information
  if (source.from?.name !== converted.from?.name) {
    issues.push(`Seller name changed: ${source.from?.name} → ${converted.from?.name}`);
  }
  
  if (source.to?.name !== converted.to?.name) {
    issues.push(`Buyer name changed: ${source.to?.name} → ${converted.to?.name}`);
  }
  
  // Check items
  if (source.items?.length !== converted.items?.length) {
    issues.push(`Items count changed: ${source.items?.length} → ${converted.items?.length}`);
  } else if (source.items && converted.items) {
    for (let i = 0; i < source.items.length; i++) {
      const sourceItem = source.items[i];
      const convertedItem = converted.items[i];
      
      if (sourceItem.name !== convertedItem.name) {
        issues.push(`Item ${i+1} name changed: ${sourceItem.name} → ${convertedItem.name}`);
      }
      
      if (sourceItem.unitNetPrice !== convertedItem.unitNetPrice) {
        issues.push(`Item ${i+1} price changed: ${sourceItem.unitNetPrice} → ${convertedItem.unitNetPrice}`);
      }
    }
  }
  
  return issues;
}

tap.start();