ci-build-site.yml

name: build-site-and-compare
on:
  push:
    branches:
    tags:
    paths-ignore:
      - 'publisher/**'
      - 'updater/**'
      - '.github/workflows/ci-build-publisher.yml'
      - '.github/workflows/ci-build-updater.yml'
      - '.github/workflows/ci-frontend-check.yml'
      - '.github/workflows/ci-frontend-lint.yml'
      - '.github/dependabot.yml'
      - '.github/FUNDING.yml'
      - 'hugo/content/**' # content likely won't break the build
  pull_request:
    paths-ignore:
      - 'publisher/**'
      - 'updater/**'
      - '.github/workflows/ci-build-publisher.yml'
      - '.github/workflows/ci-build-updater.yml'
      - '.github/workflows/ci-frontend-check.yml'
      - '.github/workflows/ci-frontend-lint.yml'
      - '.github/dependabot.yml'
      - '.github/FUNDING.yml'
      - 'hugo/content/**' # content likely won't break the build

jobs:
  build:
    name: build-and-compare
    runs-on: ubuntu-latest
    steps:
      - name: Check out code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0 # Needed to fetch all history for comparison

      - name: Set directory names
        id: set-dirs
        run: |
          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
            echo "old_dir=master" >> $GITHUB_OUTPUT
            echo "new_dir=pr-${{ github.event.pull_request.number }}" >> $GITHUB_OUTPUT
          else
            echo "old_dir=old-master" >> $GITHUB_OUTPUT
            echo "new_dir=new-master" >> $GITHUB_OUTPUT
          fi

      - name: Get comparison commit
        id: get-comparison-commit
        run: |
          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
            echo "compare_sha=$(git merge-base ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }})" >> $GITHUB_OUTPUT
          else
            echo "compare_sha=$(git rev-parse HEAD^1)" >> $GITHUB_OUTPUT
          fi

      - name: Build previous version
        run: |
          git checkout ${{ steps.get-comparison-commit.outputs.compare_sha }}
          docker build -t radio-t/site:previous --build-arg DO_NOT_MINIFY=true .
          
          # Create directories for previous build
          mkdir -p ${{ steps.set-dirs.outputs.old_dir }}/hugo
          cp -r hugo/* ${{ steps.set-dirs.outputs.old_dir }}/hugo/
          mkdir -p ${{ steps.set-dirs.outputs.old_dir }}/public
          
          # Run the container with proper volume mounts
          docker run --rm \
            -v ${{ github.workspace }}/${{ steps.set-dirs.outputs.old_dir }}/hugo:/srv/hugo \
            -v ${{ github.workspace }}/${{ steps.set-dirs.outputs.old_dir }}/public:/srv/hugo/public \
            -e DO_NOT_MINIFY_HUGO=true \
            radio-t/site:previous
          
          # Copy the generated manifest.json from the old build
          cp ${{ steps.set-dirs.outputs.old_dir }}/hugo/data/manifest.json ${{ steps.set-dirs.outputs.old_dir }}/manifest.json

      - name: Build current version
        run: |
          git checkout ${{ github.event.pull_request.head.sha || github.sha }}
          docker build -t radio-t/site:current --build-arg DO_NOT_MINIFY=true .
          
          # Create directories for current build
          mkdir -p ${{ steps.set-dirs.outputs.new_dir }}/hugo
          cp -r hugo/* ${{ steps.set-dirs.outputs.new_dir }}/hugo/
          mkdir -p ${{ steps.set-dirs.outputs.new_dir }}/public
          
          # Run the container with proper volume mounts
          docker run --rm \
            -v ${{ github.workspace }}/${{ steps.set-dirs.outputs.new_dir }}/hugo:/srv/hugo \
            -v ${{ github.workspace }}/${{ steps.set-dirs.outputs.new_dir }}/public:/srv/hugo/public \
            -e DO_NOT_MINIFY_HUGO=true \
            radio-t/site:current
          
          # Copy the generated manifest.json from the new build
          cp ${{ steps.set-dirs.outputs.new_dir }}/hugo/data/manifest.json ${{ steps.set-dirs.outputs.new_dir }}/manifest.json

      - name: Remove itunes:subtitle from RSS feeds before comparison
        run: |
          sed -i 's#<itunes:subtitle>.*</itunes:subtitle>##' ${{ steps.set-dirs.outputs.old_dir }}/public/podcast-archives-short.rss
          sed -i 's#<itunes:subtitle>.*</itunes:subtitle>##' ${{ steps.set-dirs.outputs.new_dir }}/public/podcast-archives-short.rss
          sed -i 's#<itunes:subtitle>.*</itunes:subtitle>##' ${{ steps.set-dirs.outputs.old_dir }}/public/podcast-archives.rss
          sed -i 's#<itunes:subtitle>.*</itunes:subtitle>##' ${{ steps.set-dirs.outputs.new_dir }}/public/podcast-archives.rss

      - name: Copy New Manifest and Retrieve Old Manifest
        run: |
          # Define paths to old and new manifests
          old_manifest="${{ steps.set-dirs.outputs.old_dir }}/manifest.json"
          new_manifest="${{ steps.set-dirs.outputs.new_dir }}/manifest.json"

          # Step 3: Compare manifest.json files and handle ID replacements if they differ
          if cmp -s "$old_manifest" "$new_manifest"; then
            echo "No differences in manifest.json. Skipping ID replacements."
            exit 0
          fi

          # Step 4: Extract and replace differing IDs
          while IFS= read -r old_line && IFS= read -r new_line <&3; do
            if [[ "$old_line" != "$new_line" ]]; then
              # Extract ID from both lines
              old_id=$(echo "$old_line" | grep -oP 'id=\K[^"]+')
              new_id=$(echo "$new_line" | grep -oP 'id=\K[^"]+')

              # Perform replacement if IDs differ
              if [[ -n "$old_id" && -n "$new_id" && "$old_id" != "$new_id" ]]; then
                find ${{ steps.set-dirs.outputs.new_dir }}/public -name '*.html' -exec sudo sed -i "s?id=$new_id?id=$old_id?g" {} +
              fi
            fi
          done <"$old_manifest" 3<"$new_manifest"

      - name: Generate diff
        run: |
          # Generate initial diff
          diff -r -N -u ${{ steps.set-dirs.outputs.old_dir }}/public ${{ steps.set-dirs.outputs.new_dir }}/public > temp.diff || true
          
          # Process diff file to adjust paths
          sed -E 's#^(---|\+\+\+) (.+)/public/#\1 \2/#' temp.diff > changes.diff
          
          # Store diff size for later use
          diff_size=$(wc -c < changes.diff)
          echo "diff_size=$diff_size" >> $GITHUB_ENV
          
          # Delete changes.diff if it's empty
          if [ ! -s changes.diff ]; then
              rm changes.diff
          fi
          
          # Generate a summary of changed files
          find ${{ steps.set-dirs.outputs.new_dir }}/public -type f -exec sh -c '
            old_dir="${{ steps.set-dirs.outputs.old_dir }}"
            new_dir="${{ steps.set-dirs.outputs.new_dir }}"
            file_path=${1#$new_dir/public/}
            prev_file="$old_dir/public/$file_path"
            if [ ! -f "$prev_file" ]; then
              echo "- New: \`$file_path\`"
            elif ! cmp -s "$1" "$prev_file"; then
              echo "- Modified: \`$file_path\`"
            fi
          ' sh {} \; >> changes.md
          # add line in the beginning of the file only if it's not empty
          if [ -s changes.md ]; then
              sed -i '1s/^/Changed files:\n\n/' changes.md
          fi
          
          find ${{ steps.set-dirs.outputs.old_dir }}/public -type f -exec sh -c '
            old_dir="${{ steps.set-dirs.outputs.old_dir }}"
            new_dir="${{ steps.set-dirs.outputs.new_dir }}"
            file_path=${1#$old_dir/public/}
            current_file="$new_dir/public/$file_path"
            if [ ! -f "$current_file" ]; then
              echo "- Deleted: \`$file_path\`"
            fi
          ' sh {} \; >> changes.md
          # delete summary if it's empty
          if [ ! -s changes.md ]; then
              rm changes.md
          fi

      - name: Create Pastebin Paste with the diff in case it's too large
        if: github.event_name == 'pull_request' && env.diff_size >= 20000
        env:
          PASTEBIN_API_KEY: ${{ secrets.PASTEBIN_API_KEY }}
        id: create-pastebin
        run: |
          # Use a URL-encoded paste name to handle special characters
          paste_name=$(echo "radio-t.com Site Changes for PR #${{ github.event.pull_request.number }}, commit ${{ github.sha }}" | jq -sRr @uri)
          
          # Post the diff file directly from changes.diff
          # https://pastebin.com/doc_api
          paste_output=$(curl --silent "https://pastebin.com/api/api_post.php" \
            -d "api_dev_key=$PASTEBIN_API_KEY" \
            -d "api_option=paste" \
            -d "api_paste_expire_date=1M" \
            -d "api_paste_format=diff" \
            -d "api_paste_private=0" \
            -d "api_paste_name=${paste_name}" \
            -d "api_paste_code=$(< changes.diff)" || echo "curl call to pastebin failed")

          # Check if the output is a valid URL, otherwise print an error
          if [[ "$paste_output" == "https://"* ]]; then
            echo "PASTE_URL=$paste_output" >> $GITHUB_ENV
          else
            echo "Error: Failed to create Pastebin paste: $paste_output" >&2
          fi

      - name: Upload changes.diff as artifact
        uses: actions/upload-artifact@v4
        with:
          name: changes.diff
          path: changes.diff
          if-no-files-found: ignore

      - name: Upload changes.md as artifact
        uses: actions/upload-artifact@v4
        with:
          name: changes.md
          path: changes.md
          if-no-files-found: ignore

      - name: Generate comment body in case there are changes
        if: env.diff_size != 0
        id: get-comment-body
        run: |
          SUMMARY=$(cat changes.md)
          echo "body<<EOF" >> $GITHUB_OUTPUT
          echo "### Site Build Comparison" >> $GITHUB_OUTPUT
          echo "" >> $GITHUB_OUTPUT
          echo "**Build completed at:** $(date -u '+%Y-%m-%d %H:%M:%S UTC')" >> $GITHUB_OUTPUT
          echo "" >> $GITHUB_OUTPUT
          echo "\`\`\`" >> $GITHUB_OUTPUT
          echo "$SUMMARY" >> $GITHUB_OUTPUT
          echo "\`\`\`" >> $GITHUB_OUTPUT
          echo "" >> $GITHUB_OUTPUT
          
          # If diff is small enough (<20KB), include it directly under spoiler
          if [ "$diff_size" -lt 20000 ]; then
            echo "**Full changes:**" >> $GITHUB_OUTPUT
            echo "" >> $GITHUB_OUTPUT
            echo "<details>" >> $GITHUB_OUTPUT
            echo "<summary>Click to expand diff</summary>" >> $GITHUB_OUTPUT
            echo "" >> $GITHUB_OUTPUT
            echo "\`\`\`diff" >> $GITHUB_OUTPUT
            cat changes.diff >> $GITHUB_OUTPUT
            echo "\`\`\`" >> $GITHUB_OUTPUT
            echo "</details>" >> $GITHUB_OUTPUT
          fi
          echo "[View full changes diff](${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID})" >> $GITHUB_OUTPUT
          if [ -n "$PASTE_URL" ]; then
            echo "[View diff on Pastebin]($PASTE_URL)" >> $GITHUB_OUTPUT
          fi

          echo "EOF" >> $GITHUB_OUTPUT

      - name: Generate comment body in case there are no changes
        if: env.diff_size == 0
        id: get-comment-body-no-changes
        run: |
          echo "body<<EOF" >> $GITHUB_OUTPUT
          echo "### Site Build Comparison" >> $GITHUB_OUTPUT
          echo "" >> $GITHUB_OUTPUT
          echo "**Build completed at:** $(date -u '+%Y-%m-%d %H:%M:%S UTC')" >> $GITHUB_OUTPUT
          echo "" >> $GITHUB_OUTPUT
          echo "No changes detected." >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Find existing comment
        id: find-comment
        if: github.event_name == 'pull_request'
        uses: peter-evans/find-comment@v3
        with:
          issue-number: ${{ github.event.pull_request.number }}
          body-includes: "### Site Build Comparison"

      - name: Create or update comment
        if: github.event_name == 'pull_request'
        uses: peter-evans/create-or-update-comment@v4
        with:
          comment-id: ${{ steps.find-comment.outputs.comment-id }}
          issue-number: ${{ github.event.pull_request.number }}
          body: ${{ steps.get-comment-body.outputs.body }}${{ steps.get-comment-body-no-changes.outputs.body }}
          edit-mode: replace