github-pages-deploy.yml

name: Deploy in Github Pages

on: 
  push:
    paths:
    - 'published/**'
    - 'index.css'
    - 'common/**/*.md'

permissions: 
  contents: write

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 2
      - uses: actions/setup-node@v3
        with:
          node-version: '20'
      - name: Install dependencies
        run: npm install

      - name: Get modified slide directories
        run: |
          # Get the list of modified files
          modified_files=$(git show ${{ github.sha }} --name-only)
          echo "Modified files: $modified_files"

          # Check if index.css is modified
          if echo "$modified_files" | grep -q "^index.css$"; then
            echo "index_css_modified=true" >> $GITHUB_ENV
          else
            echo "index_css_modified=false" >> $GITHUB_ENV
          fi

          # Check if any markdown files in the common directory are modified
          if echo "$modified_files" | grep -q "^common/.*\.md$"; then
            echo "common_md_modified=true" >> $GITHUB_ENV
          else
            echo "common_md_modified=false" >> $GITHUB_ENV
          fi

          # Get modified published directories
          published_dirs=$(echo "$modified_files" | grep "^published/.*/.*\.\(md\|vue\|ts\|tsx\|js\|jsx\|html\|css\)$" | xargs -I {} dirname {} | sort | uniq)
          echo "Modified slide directories: $published_dirs"

          # Temporary file to store directories
          temp_file=$(mktemp)

          # Loop through modified files and find the closest parent directory with a markdown file
          for dir in $published_dirs; do
            while [ "$dir" != "." ]; do
              if ls "$dir"/*.md >/dev/null 2>&1; then
                echo "$dir" >> "$temp_file"
                break
              fi
              dir=$(dirname "$dir")
            done
          done

          echo "Directories with markdown files: $(cat $temp_file)"

          # Remove duplicates and store the result in modified_dirs
          modified_dirs=$(sort "$temp_file" | uniq | tr '\n' ' ')

          # Clean up temporary file
          rm "$temp_file"

          echo "Unique modified directories: $modified_dirs"

          # Output the modified directories to be used as an environment variable
          echo "modified_dirs=${modified_dirs}" >> $GITHUB_ENV

      - name: Create build directory
        run: |
            mkdir -p build
            if [ "${{ env.common_md_modified }}" = "true" ]; then
              # Create folders for all slide projects if common markdown modified
              find published -type f -name "slides.md" | while read -r file; do
                dir=$(dirname "$file")
                mkdir -p build/$(echo "$dir" | awk -F'published/' '{print $2}')
              done
            else
              # Only create folders for modified directories
              for dir in ${{ env.modified_dirs }}; do
                mkdir -p build/$(echo "$dir" | awk -F'published/' '{print $2}')
              done
            fi

      - name: Build modified slides
        if: env.modified_dirs != '' || env.common_md_modified == 'true'
        run: |
          if [ "${{ env.common_md_modified }}" = "true" ]; then
            # Rebuild all slides if common markdown modified
            find published -type f -name "slides.md" | while read -r file; do
              dir=$(dirname "$file")
              npm run build -- --base /lectures/$(echo "$dir" | awk -F'published/' '{print $2}')/ $file
              mv $dir/dist/* build/$(echo "$dir" | awk -F'published/' '{print $2}') -v
            done
          else
            # Only build modified slides
            for dir in ${{ env.modified_dirs }}; do
              npm run build -- --base /lectures/$(echo "$dir" | awk -F'published/' '{print $2}')/ $dir/slides.md
              mv $dir/dist/* build/$(echo "$dir" | awk -F'published/' '{print $2}') -v
            done
          fi

      - name: Build index.html
        if: env.index_css_modified == 'true' || env.modified_dirs != '' || env.common_md_modified == 'true'
        run: |
          if [[ -f index.css ]]; then
            mv index.css build/index.css
          fi

          # Temporary file to store links
          temp_links_file=$(mktemp)

          # Find all directories containing a slides.md file and extract their relative paths
          find published -type f -name "slides.md" | while read -r file; do
            dir=$(dirname "$file")
            slide_path=$(echo "$dir" | sed 's|published/||')
            echo "$slide_path" >> "$temp_links_file"
          done

          # Sort the links lexicographically and remove duplicates
          sorted_links=$(sort "$temp_links_file" | uniq)

          echo "Sorted links: $sorted_links"

          # Begin writing the new index.html in the lectures directory
          {
            echo '<!DOCTYPE html>'
            echo '<html lang="en">'
            echo '<head>'
            echo '  <meta charset="UTF-8">'
            echo '  <meta name="viewport" content="width=device-width, initial-scale=1.0">'
            echo '  <link rel="stylesheet" href="./index.css">'
            echo '  <title>Lectures</title>'
            echo '</head>'
            echo '<body class="container">'
            echo '  <h1>Lecture Presentations</h1>'
            echo '  <ul>'

            # Add sorted links to index.html
            for link in $sorted_links; do
              echo "    <li><a href=\"$link/\">$link</a></li>"
            done

            echo '  </ul>'
            echo '</body>'
            echo '</html>'
          } > build/index.html

          # Clean up temporary files
          rm "$temp_links_file"

      - name: Deploy slides 🚀
        uses: JamesIves/github-pages-deploy-action@v4
        with:
          branch: gh-pages # The branch the action should deploy to.
          folder: build # The folder the action should deploy.
          target-folder: ''
          clean: false
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}