name: "🧪 Agent: Test Coverage"

on:
  pull_request:
    types: [opened, synchronize, reopened]

permissions:
  contents: read
  pull-requests: write

jobs:
  test-coverage:
    name: Test Coverage Agent
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
        continue-on-error: true

      - name: Get changed files
        id: changed-files
        uses: tj-actions/changed-files@v44
        with:
          files: |
            **/*.ts
            **/*.tsx
            **/*.js
            **/*.jsx

      - name: Analyze test coverage
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const path = require('path');

            const changedFiles = '${{ steps.changed-files.outputs.all_changed_files }}'.split(' ').filter(f => f);

            let report = '## 🧪 Test Coverage Agent Report\n\n';
            let stats = {
              sourceFiles: [],
              testFiles: [],
              missingTests: [],
              hasTestFramework: false
            };

            // Check for test framework
            try {
              const packageJson = JSON.parse(fs.readFileSync('package.json', 'utf8'));
              const deps = { ...packageJson.dependencies, ...packageJson.devDependencies };
              stats.hasTestFramework = !!(deps.jest || deps.vitest || deps.mocha || deps['@testing-library/react']);
            } catch (e) {}

            // Analyze changed files
            for (const file of changedFiles) {
              const isTest = file.includes('.test.') ||
                             file.includes('.spec.') ||
                             file.includes('__tests__') ||
                             file.includes('test/') ||
                             file.includes('tests/');

              if (isTest) {
                stats.testFiles.push(file);
              } else {
                stats.sourceFiles.push(file);

                // Check if corresponding test exists
                const basename = path.basename(file, path.extname(file));
                const dirname = path.dirname(file);
                const testPatterns = [
                  `${dirname}/${basename}.test${path.extname(file)}`,
                  `${dirname}/${basename}.spec${path.extname(file)}`,
                  `${dirname}/__tests__/${basename}.test${path.extname(file)}`,
                  `__tests__/${basename}.test${path.extname(file)}`,
                ];

                let hasTest = false;
                for (const testPath of testPatterns) {
                  if (fs.existsSync(testPath)) {
                    hasTest = true;
                    break;
                  }
                }

                if (!hasTest && !file.includes('index.') && !file.includes('.d.ts')) {
                  stats.missingTests.push(file);
                }
              }
            }

            // Calculate coverage percentage
            const coveragePercent = stats.sourceFiles.length > 0
              ? Math.round(((stats.sourceFiles.length - stats.missingTests.length) / stats.sourceFiles.length) * 100)
              : 100;

            // Build report
            report += '### 📊 Test Analysis\n\n';
            report += `| Metric | Value |\n`;
            report += `|--------|-------|\n`;
            report += `| Source files changed | ${stats.sourceFiles.length} |\n`;
            report += `| Test files changed | ${stats.testFiles.length} |\n`;
            report += `| Files with tests | ${stats.sourceFiles.length - stats.missingTests.length} |\n`;
            report += `| Files missing tests | ${stats.missingTests.length} |\n`;
            report += `| Test framework | ${stats.hasTestFramework ? '✅ Detected' : '❌ Not found'} |\n\n`;

            report += `### 📈 Test Coverage Score: ${coveragePercent}%\n\n`;

            // Progress bar
            const filled = Math.round(coveragePercent / 10);
            const empty = 10 - filled;
            report += `\`[${'█'.repeat(filled)}${'░'.repeat(empty)}]\`\n\n`;

            if (coveragePercent >= 80) {
              report += '✅ Excellent test coverage!\n\n';
            } else if (coveragePercent >= 50) {
              report += '⚠️ Consider adding more tests for better coverage.\n\n';
            } else {
              report += '❌ Low test coverage. Please add tests for your changes.\n\n';
            }

            // Missing tests
            if (stats.missingTests.length > 0) {
              report += '### 🔍 Files Missing Tests\n\n';
              stats.missingTests.slice(0, 10).forEach(f => {
                report += `- \`${f}\`\n`;
              });
              if (stats.missingTests.length > 10) {
                report += `\n*...and ${stats.missingTests.length - 10} more files*\n`;
              }
              report += '\n';
            }

            // Recommendations
            report += '### 💡 Recommendations\n\n';
            if (!stats.hasTestFramework) {
              report += '- Consider adding a test framework (Jest, Vitest, etc.)\n';
            }
            if (stats.testFiles.length === 0 && stats.sourceFiles.length > 0) {
              report += '- No test files in this PR - consider adding tests\n';
            }
            if (stats.missingTests.length > 0) {
              report += '- Add unit tests for the files listed above\n';
            }
            if (coveragePercent === 100) {
              report += '- All changed files have corresponding tests! 🎉\n';
            }

            report += '\n---\n*🧪 Automated analysis by Test Coverage Agent*';

            // Post comment
            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.pull_request.number,
              body: report
            });

      - name: Run tests (if available)
        continue-on-error: true
        run: |
          if [ -f "package.json" ]; then
            npm ci --ignore-scripts 2>/dev/null || npm install --ignore-scripts 2>/dev/null || true
            npm test 2>/dev/null || echo "No tests configured or tests failed"
          fi