enforce-image-size.yml

name: LiveLabs Image Validation

on:
  pull_request:
    types: [opened, synchronize, reopened]

permissions:
  contents: read

jobs:
  check-images:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Install ffmpeg
        run: |
          sudo apt-get update
          sudo apt-get install -y ffmpeg

      - name: Detect oversized images (>1280px)
        shell: bash
        run: |
          set -euo pipefail
          MAX=1280

          git fetch --no-tags --prune origin "${GITHUB_BASE_REF}:${GITHUB_BASE_REF}" || true

          mapfile -d '' files < <(
            git diff --name-only --diff-filter=AM -z "origin/${GITHUB_BASE_REF}...HEAD" -- \
              '*.png' '*.jpg' '*.jpeg' '*.PNG' '*.JPG' '*.JPEG' || true
          )

          bad=0
          for f in "${files[@]}"; do
            [[ -f "$f" ]] || continue

            dims="$(ffprobe -v error -select_streams v:0 \
              -show_entries stream=width,height \
              -of csv=p=0:s=x "$f" || true)"

            if [[ -z "$dims" ]]; then
              echo "Skipping unreadable image: $f"
              continue
            fi

            w="${dims%x*}"
            h="${dims#*x}"

            if [[ "$w" -gt "$MAX" || "$h" -gt "$MAX" ]]; then
              echo "::error file=$f::${f} is ${w}x${h}. Max allowed is ${MAX}px (either dimension)."
              bad=1
            fi
          done

          if [[ "$bad" -eq 1 ]]; then
            echo ""
            echo "One or more images exceed ${MAX}px."
            echo "Please fix this locally in your fork."
            echo ""
            echo "Note: this script requires 'ffmpeg' to be installed on your system."
            echo "  macOS (Homebrew): brew install ffmpeg"
            echo "  Ubuntu/Debian:    sudo apt-get install ffmpeg"
            echo ""
            echo "From the root directory of your workshop (not the repo root!), run:"
            echo "  ../_imgscript/resize-image.sh"
            echo ""
            echo "The script will only resize images whose width or height is greater than ${MAX}px."
            exit 1
          fi