name: "📚 Agent: Documentation"

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

permissions:
  contents: read
  pull-requests: write

jobs:
  documentation:
    name: Documentation Agent
    runs-on: ubuntu-latest

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

      - name: Get changed files
        id: changed-files
        uses: tj-actions/changed-files@v44

      - name: Analyze documentation 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 = '## 📚 Documentation Agent Report\n\n';
            let suggestions = [];
            let stats = {
              codeFiles: 0,
              docFiles: 0,
              hasJsdoc: 0,
              missingJsdoc: 0,
              readmeUpdated: false
            };

            // Categorize files
            const codeExtensions = ['.ts', '.tsx', '.js', '.jsx', '.py', '.go'];
            const docExtensions = ['.md', '.mdx', '.rst', '.txt'];

            for (const file of changedFiles) {
              const ext = path.extname(file);

              if (codeExtensions.includes(ext)) {
                stats.codeFiles++;

                // Check for JSDoc/docstrings
                try {
                  const content = fs.readFileSync(file, 'utf8');

                  // Check for exported functions without documentation
                  const exportedFunctions = content.match(/export\s+(async\s+)?function\s+\w+/g) || [];
                  const jsdocBlocks = content.match(/\/\*\*[\s\S]*?\*\//g) || [];

                  if (exportedFunctions.length > jsdocBlocks.length) {
                    stats.missingJsdoc++;
                    suggestions.push(`📝 **${file}**: Consider adding JSDoc comments to exported functions`);
                  } else if (jsdocBlocks.length > 0) {
                    stats.hasJsdoc++;
                  }

                  // Check for complex functions that need docs
                  const lines = content.split('\n').length;
                  if (lines > 200 && jsdocBlocks.length === 0) {
                    suggestions.push(`📖 **${file}**: Large file (${lines} lines) without documentation`);
                  }
                } catch (e) {
                  // File might not exist
                }
              }

              if (docExtensions.includes(ext)) {
                stats.docFiles++;
              }

              if (file.toLowerCase().includes('readme')) {
                stats.readmeUpdated = true;
              }
            }

            // Build report
            report += '### 📊 Documentation Stats\n\n';
            report += `| Metric | Value |\n`;
            report += `|--------|-------|\n`;
            report += `| Code files changed | ${stats.codeFiles} |\n`;
            report += `| Doc files changed | ${stats.docFiles} |\n`;
            report += `| Files with JSDoc | ${stats.hasJsdoc} |\n`;
            report += `| Files needing docs | ${stats.missingJsdoc} |\n`;
            report += `| README updated | ${stats.readmeUpdated ? '✅' : '❌'} |\n\n`;

            // Calculate documentation score
            const docScore = stats.codeFiles > 0
              ? Math.round((stats.hasJsdoc / stats.codeFiles) * 100)
              : 100;

            report += `### 📈 Documentation Score: ${docScore}%\n\n`;

            if (docScore >= 80) {
              report += '✅ Great documentation coverage!\n\n';
            } else if (docScore >= 50) {
              report += '⚠️ Documentation could be improved.\n\n';
            } else {
              report += '❌ Documentation coverage is low. Please add docs.\n\n';
            }

            // Suggestions
            if (suggestions.length > 0) {
              report += '### 💡 Suggestions\n\n';
              suggestions.slice(0, 10).forEach(s => report += `- ${s}\n`);
              if (suggestions.length > 10) {
                report += `\n*...and ${suggestions.length - 10} more suggestions*\n`;
              }
            }

            // Tips
            if (stats.codeFiles > 0 && !stats.readmeUpdated) {
              report += '\n### 💡 Tip\n';
              report += 'Consider updating the README if this PR introduces new features or API changes.\n';
            }

            report += '\n---\n*📚 Automated review by Documentation 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
            });