import { tap } from '@git.zone/tstest/tapbundle';
import * as plugins from '../plugins.js';
import { EInvoice } from '../../../ts/index.js';
import { PerformanceTracker } from '../performance.tracker.js';

const performanceTracker = new PerformanceTracker('EDGE-01: Empty Invoice Files');

tap.test('EDGE-01: Empty Invoice Files - should handle empty and near-empty files gracefully', async (t) => {
  const einvoice = new EInvoice();

  // Test 1: Completely empty file
  const completelyEmpty = await performanceTracker.measureAsync(
    'completely-empty-file',
    async () => {
      const emptyContent = '';
      
      try {
        const result = await einvoice.parseDocument(emptyContent);
        
        return {
          handled: true,
          parsed: !!result,
          error: null,
          contentLength: emptyContent.length
        };
      } catch (error) {
        return {
          handled: true,
          parsed: false,
          error: error.message,
          errorType: error.constructor.name
        };
      }
    }
  );

  t.ok(completelyEmpty.handled, 'Completely empty file was handled');
  t.notOk(completelyEmpty.parsed, 'Empty file was not parsed as valid');

  // Test 2: Only whitespace
  const onlyWhitespace = await performanceTracker.measureAsync(
    'only-whitespace',
    async () => {
      const whitespaceVariants = [
        ' ',
        '\n',
        '\r\n',
        '\t',
        '   \n\n\t\t  \r\n  ',
        ' '.repeat(1000)
      ];
      
      const results = [];
      
      for (const content of whitespaceVariants) {
        try {
          const result = await einvoice.parseDocument(content);
          results.push({
            content: content.replace(/\n/g, '\\n').replace(/\r/g, '\\r').replace(/\t/g, '\\t'),
            length: content.length,
            parsed: !!result,
            error: null
          });
        } catch (error) {
          results.push({
            content: content.replace(/\n/g, '\\n').replace(/\r/g, '\\r').replace(/\t/g, '\\t'),
            length: content.length,
            parsed: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  onlyWhitespace.forEach(result => {
    t.notOk(result.parsed, `Whitespace-only content not parsed: "${result.content}"`);
  });

  // Test 3: Empty XML structure
  const emptyXMLStructure = await performanceTracker.measureAsync(
    'empty-xml-structure',
    async () => {
      const emptyStructures = [
        '<?xml version="1.0" encoding="UTF-8"?>',
        '<?xml version="1.0" encoding="UTF-8"?>\n',
        '<?xml version="1.0" encoding="UTF-8"?><Invoice></Invoice>',
        '<?xml version="1.0" encoding="UTF-8"?><Invoice/>',
        '<Invoice></Invoice>',
        '<Invoice/>'
      ];
      
      const results = [];
      
      for (const xml of emptyStructures) {
        try {
          const result = await einvoice.parseDocument(xml);
          const validation = await einvoice.validate(result);
          
          results.push({
            xml: xml.substring(0, 50),
            parsed: true,
            valid: validation?.isValid || false,
            hasContent: !!result && Object.keys(result).length > 0
          });
        } catch (error) {
          results.push({
            xml: xml.substring(0, 50),
            parsed: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  emptyXMLStructure.forEach(result => {
    if (result.parsed) {
      t.notOk(result.valid, 'Empty XML structure is not valid invoice');
    }
  });

  // Test 4: Empty required fields
  const emptyRequiredFields = await performanceTracker.measureAsync(
    'empty-required-fields',
    async () => {
      const testCases = [
        {
          name: 'empty-id',
          xml: `<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2">
  <ID></ID>
  <IssueDate>2024-01-01</IssueDate>
</Invoice>`
        },
        {
          name: 'whitespace-id',
          xml: `<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2">
  <ID>   </ID>
  <IssueDate>2024-01-01</IssueDate>
</Invoice>`
        },
        {
          name: 'empty-amount',
          xml: `<?xml version="1.0" encoding="UTF-8"?>
<Invoice>
  <ID>INV-001</ID>
  <TotalAmount></TotalAmount>
</Invoice>`
        }
      ];
      
      const results = [];
      
      for (const testCase of testCases) {
        try {
          const parsed = await einvoice.parseDocument(testCase.xml);
          const validation = await einvoice.validate(parsed);
          
          results.push({
            name: testCase.name,
            parsed: true,
            valid: validation?.isValid || false,
            errors: validation?.errors || []
          });
        } catch (error) {
          results.push({
            name: testCase.name,
            parsed: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  emptyRequiredFields.forEach(result => {
    t.notOk(result.valid, `${result.name} is not valid`);
  });

  // Test 5: Zero-byte file
  const zeroByteFile = await performanceTracker.measureAsync(
    'zero-byte-file',
    async () => {
      const zeroByteBuffer = Buffer.alloc(0);
      
      try {
        const result = await einvoice.parseDocument(zeroByteBuffer);
        
        return {
          handled: true,
          parsed: !!result,
          bufferLength: zeroByteBuffer.length
        };
      } catch (error) {
        return {
          handled: true,
          parsed: false,
          error: error.message,
          bufferLength: zeroByteBuffer.length
        };
      }
    }
  );

  t.ok(zeroByteFile.handled, 'Zero-byte buffer was handled');
  t.equal(zeroByteFile.bufferLength, 0, 'Buffer length is zero');

  // Test 6: Empty arrays and objects
  const emptyCollections = await performanceTracker.measureAsync(
    'empty-collections',
    async () => {
      const testCases = [
        {
          name: 'empty-line-items',
          xml: `<?xml version="1.0" encoding="UTF-8"?>
<Invoice>
  <ID>INV-001</ID>
  <InvoiceLines></InvoiceLines>
</Invoice>`
        },
        {
          name: 'empty-tax-totals',
          xml: `<?xml version="1.0" encoding="UTF-8"?>
<Invoice>
  <ID>INV-001</ID>
  <TaxTotal></TaxTotal>
</Invoice>`
        }
      ];
      
      const results = [];
      
      for (const testCase of testCases) {
        try {
          const parsed = await einvoice.parseDocument(testCase.xml);
          
          results.push({
            name: testCase.name,
            parsed: true,
            hasEmptyCollections: true,
            structure: JSON.stringify(parsed).substring(0, 100)
          });
        } catch (error) {
          results.push({
            name: testCase.name,
            parsed: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  emptyCollections.forEach(result => {
    t.ok(result.parsed || result.error, `${result.name} was processed`);
  });

  // Test 7: Empty PDF files
  const emptyPDFFiles = await performanceTracker.measureAsync(
    'empty-pdf-files',
    async () => {
      const pdfTests = [
        {
          name: 'empty-pdf-header',
          content: Buffer.from('%PDF-1.4\n%%EOF')
        },
        {
          name: 'pdf-no-content',
          content: Buffer.from('%PDF-1.4\n1 0 obj\n<<>>\nendobj\nxref\n0 1\n0000000000 65535 f\ntrailer\n<</Size 1>>\n%%EOF')
        },
        {
          name: 'zero-byte-pdf',
          content: Buffer.alloc(0)
        }
      ];
      
      const results = [];
      
      for (const test of pdfTests) {
        try {
          const result = await einvoice.extractFromPDF(test.content);
          
          results.push({
            name: test.name,
            processed: true,
            hasXML: !!result?.xml,
            hasAttachments: result?.attachments?.length > 0,
            size: test.content.length
          });
        } catch (error) {
          results.push({
            name: test.name,
            processed: false,
            error: error.message,
            size: test.content.length
          });
        }
      }
      
      return results;
    }
  );

  emptyPDFFiles.forEach(result => {
    t.ok(!result.hasXML, `${result.name} has no XML content`);
  });

  // Test 8: Format detection on empty files
  const formatDetectionEmpty = await performanceTracker.measureAsync(
    'format-detection-empty',
    async () => {
      const emptyVariants = [
        { content: '', name: 'empty-string' },
        { content: ' ', name: 'space' },
        { content: '\n', name: 'newline' },
        { content: '<?xml?>', name: 'incomplete-xml-declaration' },
        { content: '<', name: 'single-bracket' },
        { content: Buffer.alloc(0), name: 'empty-buffer' }
      ];
      
      const results = [];
      
      for (const variant of emptyVariants) {
        try {
          const format = await einvoice.detectFormat(variant.content);
          
          results.push({
            name: variant.name,
            detected: !!format,
            format: format,
            confidence: format?.confidence || 0
          });
        } catch (error) {
          results.push({
            name: variant.name,
            detected: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  formatDetectionEmpty.forEach(result => {
    t.notOk(result.detected, `Format not detected for ${result.name}`);
  });

  // Test 9: Empty namespace handling
  const emptyNamespaces = await performanceTracker.measureAsync(
    'empty-namespace-handling',
    async () => {
      const namespaceTests = [
        {
          name: 'empty-default-namespace',
          xml: '<Invoice xmlns=""></Invoice>'
        },
        {
          name: 'empty-prefix-namespace',
          xml: '<ns:Invoice xmlns:ns=""></ns:Invoice>'
        },
        {
          name: 'whitespace-namespace',
          xml: '<Invoice xmlns="   "></Invoice>'
        }
      ];
      
      const results = [];
      
      for (const test of namespaceTests) {
        try {
          const parsed = await einvoice.parseDocument(test.xml);
          
          results.push({
            name: test.name,
            parsed: true,
            hasNamespace: !!parsed?.namespace
          });
        } catch (error) {
          results.push({
            name: test.name,
            parsed: false,
            error: error.message
          });
        }
      }
      
      return results;
    }
  );

  emptyNamespaces.forEach(result => {
    t.ok(result.parsed !== undefined, `${result.name} was processed`);
  });

  // Test 10: Recovery from empty files
  const emptyFileRecovery = await performanceTracker.measureAsync(
    'empty-file-recovery',
    async () => {
      const recoveryTest = async () => {
        const results = {
          emptyHandled: false,
          normalAfterEmpty: false,
          batchWithEmpty: false
        };
        
        // Test 1: Handle empty file
        try {
          await einvoice.parseDocument('');
        } catch (error) {
          results.emptyHandled = true;
        }
        
        // Test 2: Parse normal file after empty
        try {
          const normal = await einvoice.parseDocument(
            '<?xml version="1.0"?><Invoice><ID>TEST</ID></Invoice>'
          );
          results.normalAfterEmpty = !!normal;
        } catch (error) {
          // Should not happen
        }
        
        // Test 3: Batch with empty file
        try {
          const batch = await einvoice.batchProcess([
            '<?xml version="1.0"?><Invoice><ID>1</ID></Invoice>',
            '',
            '<?xml version="1.0"?><Invoice><ID>2</ID></Invoice>'
          ]);
          results.batchWithEmpty = batch?.processed === 2;
        } catch (error) {
          // Batch might fail completely
        }
        
        return results;
      };
      
      return await recoveryTest();
    }
  );

  t.ok(emptyFileRecovery.normalAfterEmpty, 'Can parse normal file after empty file');

  // Print performance summary
  performanceTracker.printSummary();
});

// Run the test
tap.start();