preview.yml

name: Quarto Preview

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

# Cancel an in-progress preview build when a newer event supersedes it on
# the same ref — otherwise a fresh push queues behind the stale build and
# the up-to-date preview is delayed until the obsolete one finishes (see
# d-morrison/rme#812). `github.ref` is stable across a PR's events, so all
# of a PR's preview runs share one group.
concurrency:
  group: preview-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build-deploy:
    if: |
      (github.event.action != 'labeled' && github.event.action != 'unlabeled') ||
      contains(fromJson('["revealjs","pdf","docx","no-preview-highlights","clear-freezer"]'), github.event.label.name)
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    env:
      TZ: America/Los_Angeles
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Fetch full history for git diff

      - name: Set up Quarto
        uses: quarto-dev/quarto-actions/setup@v2
        with:
          tinytex: true
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}


      - uses: r-lib/actions/setup-r@v2
        with:
          use-public-rspm: true

      - uses: r-lib/actions/setup-r-dependencies@v2
        with:
          packages: |
            any::knitr
            any::rmarkdown
            any::tibble

      - name: Restore Quarto freezer
        if: ${{ !contains(github.event.pull_request.labels.*.name, 'clear-freezer') }}
        id: quarto-freezer-cache
        uses: actions/cache/restore@v4
        with:
          path: _freeze
          key: ${{ runner.os }}-quarto-freezer-${{ github.event.pull_request.head.sha }}-${{ github.run_attempt }}
          restore-keys: |
            ${{ runner.os }}-quarto-freezer-${{ github.event.pull_request.head.sha }}-
            ${{ runner.os }}-quarto-freezer-main-
            ${{ runner.os }}-quarto-freezer-

      - name: Render HTML
        uses: quarto-dev/quarto-actions/render@v2
        with:
          to: html

      # Detect which chapters have changed and optionally disable highlighting
      # based on the 'no-preview-highlights' PR label
      - name: Detect changed chapters (based on rendered files)
        run: python3 .github/scripts/detect-changed-chapters.py
        env:
          HTML_DIR: ./_site
          # Set to 'true' if PR has 'no-preview-highlights' label
          DISABLE_PREVIEW_HIGHLIGHTS: ${{ contains(github.event.pull_request.labels.*.name, 'no-preview-highlights') }}

      - name: Inject preview metadata
        if: env.PREVIEW_SHOW_HIGHLIGHTS == 'true'
        run: python3 .github/scripts/inject-preview-metadata.py

      - name: Re-render with metadata
        if: env.PREVIEW_SHOW_HIGHLIGHTS == 'true'
        uses: quarto-dev/quarto-actions/render@v2
        with:
          to: html

      - name: Collect QMD files for optional renders
        id: optional-render-files
        run: |
          files=()
          if [ -f index.qmd ]; then
            files+=(index.qmd)
          fi
          if [ -d chapters ]; then
            while IFS= read -r chapter_file; do
              files+=("$chapter_file")
            done < <(find chapters -maxdepth 1 -type f -name '*.qmd' | sort)
          fi
          if [ ${#files[@]} -eq 0 ]; then
            echo "has_files=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          {
            echo "files<<EOF"
            printf '%s\n' "${files[@]}"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"
          echo "has_files=true" >> "$GITHUB_OUTPUT"

      - name: Render Reveal.js slides
        if: contains(github.event.pull_request.labels.*.name, 'revealjs') && steps.optional-render-files.outputs.has_files == 'true'
        run: |
          while IFS= read -r file; do
            [ -n "$file" ] || continue
            echo "Rendering Reveal.js for $file"
            quarto render "$file" --to revealjs
          done <<< "${{ steps.optional-render-files.outputs.files }}"

      - name: Render PDF
        if: contains(github.event.pull_request.labels.*.name, 'pdf') && steps.optional-render-files.outputs.has_files == 'true'
        run: |
          while IFS= read -r file; do
            [ -n "$file" ] || continue
            echo "Rendering PDF for $file"
            quarto render "$file" --to pdf
          done <<< "${{ steps.optional-render-files.outputs.files }}"

      - name: Render DOCX
        if: contains(github.event.pull_request.labels.*.name, 'docx') && steps.optional-render-files.outputs.has_files == 'true'
        run: |
          while IFS= read -r file; do
            [ -n "$file" ] || continue
            echo "Rendering DOCX for $file"
            quarto render "$file" --to docx
          done <<< "${{ steps.optional-render-files.outputs.files }}"

      - name: Install python-docx for DOCX comparison
        if: contains(github.event.pull_request.labels.*.name, 'docx')
        run: pip install python-docx

      - name: Highlight HTML content changes
        if: env.PREVIEW_SHOW_HIGHLIGHTS == 'true'
        run: |
          echo "Changed chapters:"
          echo "${{ env.PREVIEW_CHANGED_CHAPTERS }}"
          python3 .github/scripts/highlight-html-changes.py
        env:
          HTML_DIR: ./_site
          PREVIEW_CHANGED_CHAPTERS: ${{ env.PREVIEW_CHANGED_CHAPTERS }}

      - name: Create DOCX with tracked changes
        if: contains(github.event.pull_request.labels.*.name, 'docx')
        run: python3 .github/scripts/create-docx-tracked-changes.py
        env:
          DOCX_DIR: ./_site

      - name: Add home page banner
        run: python3 .github/scripts/add-home-banner.py
        env:
          HTML_DIR: ./_site
          PREVIEW_CHANGED_CHAPTERS: ${{ env.PREVIEW_CHANGED_CHAPTERS }}

      - name: Save Quarto freezer
        uses: actions/cache/save@v4
        with:
          path: _freeze
          key: ${{ runner.os }}-quarto-freezer-${{ github.event.pull_request.head.sha }}-${{ github.run_attempt }}

      - name: Deploy PR Preview
        id: preview-step
        if: github.event_name == 'pull_request'
        uses: rossjrw/pr-preview-action@v1
        with:
          source-dir: ./_site/
          # Deploy on label changes too, not just open/reopen/synchronize
          # The 'auto' action ignores label events, so we explicitly set 'deploy' for non-closed PRs
          action: ${{ github.event.action == 'closed' && 'remove' || 'deploy' }}
          preview-branch: gh-pages
          comment: "false"
          wait-for-pages-deployment: false

      # Create sticky comment with preview link
      # Following https://github.com/rossjrw/pr-preview-action?tab=readme-ov-file#customise-the-sticky-comment
      - uses: marocchino/sticky-pull-request-comment@v2
        if: steps.preview-step.outputs.deployment-action == 'deploy' && env.deployment_status == 'success'
        with:
          header: pr-preview
          recreate: true
          message: |
              [PR Preview Action](https://github.com/rossjrw/pr-preview-action) ${{ steps.preview-step.outputs.action-version }}
              :---:
              | <p><img src="https://qr.rossjrw.com/?url=${{ steps.preview-step.outputs.preview-url }}" height="100" align="right" alt="QR code for preview link"></p> :rocket: View preview at <br> ${{ steps.preview-step.outputs.preview-url }} <br><br>
              | <h6>Built to branch [`gh-pages`](${{ github.server_url }}/${{ github.repository }}/tree/gh-pages) at ${{ steps.preview-step.outputs.action-start-time }}. <br> Preview will be ready when the [GitHub Pages deployment](${{ github.server_url }}/${{ github.repository }}/deployments) is complete. <br><br> </h6>

      - uses: marocchino/sticky-pull-request-comment@v2
        if: steps.preview-step.outputs.deployment-action == 'remove' && env.deployment_status == 'success'
        with:
            header: pr-preview
            recreate: true
            message: |
                [PR Preview Action](https://github.com/rossjrw/pr-preview-action) ${{ steps.preview-step.outputs.action-version }}
                :---:
                Preview removed because the pull request was closed.
                ${{ steps.preview-step.outputs.action-start-time }}