pr-preview.yml

name: Deploy PR Preview

on:
  pull_request:
    types:
      - opened
      - reopened
      - synchronize
      - closed

# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
permissions:
  contents: read
  pages: write
  id-token: write
  pull-requests: write

# Allow only one concurrent deployment per PR
concurrency:
  group: pr-preview-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  # Build job
  build:
    runs-on: ubuntu-latest
    # Don't run on closed PRs
    if: github.event.action != 'closed'
    
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '22.9.0'

      - name: Setup Yarn Corepack
        run: corepack enable

      - name: Install dependencies
        run: yarn install

      - name: Build Storybook
        run: yarn build-storybook

      # Verify the build output
      - name: Verify build output
        run: |
          echo "Checking build output directory..."
          ls -la apps/docs/storybook-static
          echo "Checking for index.html..."
          if [ -f apps/docs/storybook-static/index.html ]; then
            echo "index.html exists"
          else
            echo "index.html does not exist"
            exit 1
          fi

      # Add a comment to the PR with the preview URL
      - name: Comment PR
        uses: actions/github-script@v6
        with:
          script: |
            const previewUrl = `https://lambda-curry.github.io/forms/pr-${context.issue.number}/`;
            const commentBody = `📝 **Storybook Preview**: [View Storybook](${previewUrl})

            This preview will be updated automatically when you push new changes to this PR.
            
            > Note: The preview will be available after the workflow completes and the PR is approved for deployment.`;
            
            // Get existing comments
            const comments = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });
            
            // Check if we already have a comment
            const botComment = comments.data.find(comment => 
              comment.user.login === 'github-actions[bot]' && 
              comment.body.includes('Storybook Preview')
            );
            
            if (botComment) {
              // Update existing comment
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: botComment.id,
                body: commentBody
              });
            } else {
              // Create new comment
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                body: commentBody
              });
            }

      # Create PR-specific directory structure
      - name: Create PR-specific directory
        run: |
          mkdir -p pr-preview/pr-${{ github.event.pull_request.number }}
          cp -r apps/docs/storybook-static/* pr-preview/pr-${{ github.event.pull_request.number }}/

      # Upload the artifact for the deployment job
      - name: Upload artifact
        uses: actions/upload-pages-artifact@v3
        with:
          path: pr-preview
          retention-days: 30

  # Deploy job
  deploy:
    needs: build
    runs-on: ubuntu-latest
    if: github.event.action != 'closed'
    
    # Use a specific environment with protection rules
    # This ensures only approved PRs can deploy
    environment:
      name: pr-preview
      url: ${{ steps.deployment.outputs.page_url }}
    
    steps:
      - name: Setup Pages
        uses: actions/configure-pages@v5
        
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v4

  # Clean up when PR is closed
  cleanup:
    runs-on: ubuntu-latest
    if: github.event.action == 'closed'
    permissions:
      contents: write
    
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          ref: gh-pages
          
      - name: Delete PR Preview
        run: |
          PR_NUMBER="${{ github.event.pull_request.number }}"
          PR_PREVIEW_PATH="pr-preview/pr-$PR_NUMBER"
          
          if [ -d "$PR_PREVIEW_PATH" ]; then
            echo "Removing PR preview at $PR_PREVIEW_PATH"
            rm -rf "$PR_PREVIEW_PATH"
            
            # Commit and push the changes
            git config user.name "GitHub Actions"
            git config user.email "actions@github.com"
            git add -A
            git commit -m "Remove PR preview for PR #$PR_NUMBER" || echo "No changes to commit"
            git push
          else
            echo "PR preview directory not found"
          fi