---
# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json
name: PR Security Analysis

on:
  pull_request:
    paths:
      - '**/package.json'
      - '**/package-lock.json'
      - '**/yarn.lock'
      - '**/pnpm-lock.yaml'
      - '**/requirements.txt'
      - '**/Dockerfile'
      - '**/*.py'
      - '**/*.js'
      - '**/*.ts'
      - '**/*.yml'
      - '**/*.yaml'
      - '.github/workflows/**'

permissions:
  contents: read
  pull-requests: write
  issues: write
  actions: read

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  security-analysis:
    name: Security Analysis
    runs-on: ubuntu-latest

    steps:
      - name: Checkout PR
        uses: actions/checkout@71cf2267d89c5cb81562390fa70a37fa40b1305e # v6-beta
        with:
          fetch-depth: 0
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Fetch PR Base
        run: |
          set -eu
          # Fetch the base ref from base repository with authentication (works for private repos and forked PRs)
          # Using ref instead of SHA because git fetch requires ref names, not raw commit IDs
          # Use authenticated URL to avoid 403/404 on private repositories
          git fetch --no-tags --depth=1 \
            "https://x-access-token:${{ github.token }}@github.com/${{ github.event.pull_request.base.repo.full_name }}" \
            ${{ github.event.pull_request.base.ref }}:refs/remotes/origin-base/${{ github.event.pull_request.base.ref }}
          # Record the base commit for diffing without checking it out
          # Keep PR head checked out so scanners analyze the new changes
          BASE_REF="refs/remotes/origin-base/${{ github.event.pull_request.base.ref }}"
          echo "BASE_REF=${BASE_REF}" >> "$GITHUB_ENV"
          echo "Base ref: ${BASE_REF}"
          git log -1 --oneline "${BASE_REF}"

      - name: OWASP Dependency Check
        # Only run on pull_request, not pull_request_target to prevent executing
        # untrusted third-party actions against PR head from forks
        if: github.event_name == 'pull_request'
        uses: dependency-check/Dependency-Check_Action@3102a65fd5f36d0000297576acc56a475b0de98d # main
        with:
          project: 'PR Security Analysis'
          path: '.'
          format: 'JSON'
          out: 'reports'
          args: >
            --enableRetired --enableExperimental --failOnCVSS 0
        continue-on-error: true

      - name: Semgrep Static Analysis
        uses: semgrep/semgrep-action@713efdd345f3035192eaa63f56867b88e63e4e5d # v1
        with:
          config: 'auto'
          generateSarif: 'true'
        env:
          SEMGREP_APP_TOKEN: ${{ github.event_name != 'pull_request_target' && secrets.SEMGREP_APP_TOKEN || '' }}
        continue-on-error: true

      - name: TruffleHog Secret Scan
        uses: trufflesecurity/trufflehog@0f58ae7c5036094a1e3e750d18772af92821b503
        with:
          path: ./
          base: ${{ env.BASE_REF }}
          head: HEAD
          extra_args: --debug --only-verified --json --output /tmp/trufflehog_output.json
        continue-on-error: true

      - name: Analyze Security Results
        id: analyze
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
        with:
          script: |-
            const fs = require('fs');
            const path = require('path');

            // Unique marker to identify our bot comment
            const SECURITY_COMMENT_MARKER = '<!-- security-analysis-bot-comment -->';

            const findings = {
              permissions: [],
              actions: [],
              secrets: [],
              vulnerabilities: [],
              dependencies: []
            };

            // Analyze GitHub Actions permission changes
            const { execSync } = require('child_process');
            const baseRef = process.env.BASE_REF;
            try {
              const changedWorkflows = execSync(
                `git diff --name-only ${baseRef}...HEAD | grep -E "\.github/workflows/.*\.ya?ml$" || true`,
                { encoding: 'utf8' }
              ).trim().split('\n').filter(Boolean);

              for (const workflow of changedWorkflows) {
                if (!workflow) continue;

                try {
                  const oldContent = execSync(`git show ${baseRef}:${workflow}`, { encoding: 'utf8' });
                  const newContent = fs.readFileSync(workflow, 'utf8');

                  // Simple permission extraction (could be enhanced with YAML parsing)
                  const oldPerms = oldContent.match(/permissions:\s*\n([\s\S]*?)(?=\n\w|\n$|$)/);
                  const newPerms = newContent.match(/permissions:\s*\n([\s\S]*?)(?=\n\w|\n$|$)/);

                  if (oldPerms?.[1] !== newPerms?.[1]) {
                    findings.permissions.push({
                      file: workflow,
                      old: oldPerms?.[1]?.trim() || 'None',
                      new: newPerms?.[1]?.trim() || 'None'
                    });
                  }

                  // Check for new actions
                  const oldActions = [...oldContent.matchAll(/uses:\s*([^\s\n]+)/g)].map(m => m[1]);
                  const newActions = [...newContent.matchAll(/uses:\s*([^\s\n]+)/g)].map(m => m[1]);
                  const addedActions = newActions.filter(action => !oldActions.includes(action));

                  if (addedActions.length > 0) {
                    findings.actions.push({
                      file: workflow,
                      added: addedActions
                    });
                  }
                } catch (error) {
                  console.log(`Could not analyze ${workflow}: ${error.message}`);
                }
              }
            } catch (error) {
              console.log('No workflow changes detected');
            }

            // Parse OWASP Dependency Check results
            try {
              const owaspResults = JSON.parse(fs.readFileSync('reports/dependency-check-report.json', 'utf8'));
              if (owaspResults.dependencies) {
                owaspResults.dependencies.forEach(dep => {
                  if (dep.vulnerabilities && dep.vulnerabilities.length > 0) {
                    dep.vulnerabilities.forEach(vuln => {
                      findings.dependencies.push({
                        file: dep.fileName || 'Unknown',
                        cve: vuln.name,
                        severity: vuln.severity || 'Unknown',
                        description: vuln.description || 'No description'
                      });
                    });
                  }
                });
              }
            } catch (error) {
              console.log('No OWASP results found');
            }

            // Parse Semgrep SARIF results
            try {
              if (fs.existsSync('semgrep.sarif')) {
                const sarifContent = JSON.parse(fs.readFileSync('semgrep.sarif', 'utf8'));
                if (sarifContent.runs && sarifContent.runs[0] && sarifContent.runs[0].results) {
                  const run = sarifContent.runs[0];
                  const rules = run.tool?.driver?.rules || [];
                  run.results.forEach(result => {
                    const rule = rules.find(r => r.id === result.ruleId);
                    findings.vulnerabilities.push({
                      file: result.locations?.[0]?.physicalLocation?.artifactLocation?.uri || 'Unknown',
                      line: result.locations?.[0]?.physicalLocation?.region?.startLine || 0,
                      rule: result.ruleId,
                      severity: result.level?.toUpperCase() || 'INFO',
                      message: result.message?.text || rule?.shortDescription?.text || 'No description'
                    });
                  });
                }
              }
            } catch (error) {
              console.log('Semgrep SARIF parsing completed');
            }

            // Parse TruffleHog results (NDJSON format - one JSON object per line)
            try {
              const truffleOutput = execSync('cat /tmp/trufflehog_output.json || echo ""', { encoding: 'utf8' });
              const truffleLines = truffleOutput.trim().split('\n').filter(line => line.length > 0);

              truffleLines.forEach((line, index) => {
                try {
                  const result = JSON.parse(line);
                  findings.secrets.push({
                    file: result.SourceMetadata?.Data?.Filesystem?.file || 'Unknown',
                    line: result.SourceMetadata?.Data?.Filesystem?.line || 0,
                    detector: result.DetectorName,
                    verified: result.Verified || false
                  });
                } catch (parseError) {
                  // Log only safe metadata to avoid leaking secrets
                  console.log('Failed to parse TruffleHog line at index', index, '- Error:', parseError.message, '(line length:', line.length, 'chars)');
                }
              });

              if (truffleLines.length === 0) {
                console.log('No secrets detected');
              }
            } catch (error) {
              console.log('No TruffleHog output file found');
            }

            // Generate clean comment sections
            const sections = [];

            // GitHub Actions Permissions Changes
            if (findings.permissions.length > 0) {
              const permSection = ['## 🔐 GitHub Actions Permissions Changes'];
              findings.permissions.forEach(change => {
                permSection.push(`\n**${change.file}**:`);

                // Parse permissions into lines
                const oldLines = (change.old === 'None' ? [] : change.old.split('\n').map(l => l.trim()).filter(Boolean));
                const newLines = (change.new === 'None' ? [] : change.new.split('\n').map(l => l.trim()).filter(Boolean));

                // Create sets for comparison
                const oldSet = new Set(oldLines);
                const newSet = new Set(newLines);

                // Find added, removed, and unchanged
                const removed = oldLines.filter(l => !newSet.has(l));
                const added = newLines.filter(l => !oldSet.has(l));
                const unchanged = oldLines.filter(l => newSet.has(l));

                // Only show diff if there are actual changes
                if (removed.length > 0 || added.length > 0) {
                  permSection.push('```diff');

                  // Show removed permissions
                  removed.forEach(line => permSection.push(`- ${line}`));

                  // Show added permissions
                  added.forEach(line => permSection.push(`+ ${line}`));

                  permSection.push('```');

                  // Summary for context
                  if (unchanged.length > 0 && unchanged.length <= 3) {
                    permSection.push(`<details><summary>Unchanged (${unchanged.length})</summary>\n\n${unchanged.map(l => `- ${l}`).join('\n')}\n</details>`);
                  } else if (unchanged.length > 3) {
                    permSection.push(`<sub>*${unchanged.length} permissions unchanged*</sub>`);
                  }
                }
              });
              sections.push(permSection.join('\n'));
            }

            // New/Changed Actions
            if (findings.actions.length > 0) {
              const actionSection = ['## 🎯 New GitHub Actions'];
              findings.actions.forEach(change => {
                actionSection.push(`**${change.file}**:`);
                change.added.forEach(action => {
                  actionSection.push(`- \`${action}\``);
                });
              });
              sections.push(actionSection.join('\n'));
            }

            // Secrets Detected
            if (findings.secrets.length > 0) {
              const secretSection = ['## 🔑 Secrets Detected'];
              findings.secrets.forEach(secret => {
                const verified = secret.verified ? '🚨 **VERIFIED**' : '⚠️ Potential';
                secretSection.push(`- ${verified} ${secret.detector} in \`${secret.file}:${secret.line}\``);
              });
              sections.push(secretSection.join('\n'));
            }

            // Security Vulnerabilities
            if (findings.vulnerabilities.length > 0) {
              const vulnSection = ['## ⚠️ Security Vulnerabilities'];
              const groupedBySeverity = findings.vulnerabilities.reduce((acc, vuln) => {
                const sev = vuln.severity.toUpperCase();
                if (!acc[sev]) acc[sev] = [];
                acc[sev].push(vuln);
                return acc;
              }, {});

              ['ERROR', 'WARNING', 'INFO'].forEach(severity => {
                if (groupedBySeverity[severity]) {
                  vulnSection.push(`\n**${severity} Severity:**`);
                  groupedBySeverity[severity].forEach(vuln => {
                    vulnSection.push(`- \`${vuln.file}:${vuln.line}\` - ${vuln.message}`);
                    vulnSection.push(`  - Rule: \`${vuln.rule}\``);
                  });
                }
              });
              sections.push(vulnSection.join('\n'));
            }

            // Dependency Issues
            if (findings.dependencies.length > 0) {
              const depSection = ['## 📦 Dependency Vulnerabilities'];
              const groupedBySeverity = findings.dependencies.reduce((acc, dep) => {
                const sev = dep.severity.toUpperCase();
                if (!acc[sev]) acc[sev] = [];
                acc[sev].push(dep);
                return acc;
              }, {});

              ['CRITICAL', 'HIGH', 'MEDIUM', 'LOW'].forEach(severity => {
                if (groupedBySeverity[severity]) {
                  depSection.push(`\n**${severity} Severity:**`);
                  groupedBySeverity[severity].forEach(dep => {
                    depSection.push(`- **${dep.cve}** in \`${dep.file}\``);
                    depSection.push(`  - ${dep.description.substring(0, 100)}...`);
                  });
                }
              });
              sections.push(depSection.join('\n'));
            }

            // Count critical issues for output
            const criticalCount =
              findings.secrets.filter(s => s.verified).length +
              (findings.vulnerabilities.filter(v => v.severity.toUpperCase() === 'ERROR').length || 0) +
              (findings.dependencies.filter(d => d.severity.toUpperCase() === 'CRITICAL').length || 0);

            // Export critical count as output
            core.setOutput('critical_issues', criticalCount.toString());

            // Generate final comment with unique marker
            let comment = `${SECURITY_COMMENT_MARKER}\n## ✅ Security Analysis\n\n`;
            if (sections.length === 0) {
              comment += 'No security issues detected in this PR.';
            } else {
              comment += sections.join('\n\n');
            }

            // Find existing security comment using unique marker
            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number
            });

            const existingComment = comments.find(comment =>
              comment.body && comment.body.includes(SECURITY_COMMENT_MARKER)
            );

            if (existingComment) {
              // Update existing comment
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existingComment.id,
                body: comment
              });
            } else {
              // Create new comment
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body: comment
              });
            }

      - name: Check Critical Issues
        if: always()
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
        env:
          CRITICAL_COUNT: ${{ steps.analyze.outputs.critical_issues || '0' }}
        with:
          script: |-
            const criticalCount = parseInt(process.env.CRITICAL_COUNT || '0', 10);

            if (criticalCount > 0) {
              core.setFailed(`Found ${criticalCount} critical security issue(s). Please review and address them before merging.`);
            } else {
              console.log('No critical security issues found.');
            }