name: three.js demos → GitHub Pages

# Publishes the ADR-097 three.js demos under gh-pages/three.js/.
# Uses keep_files: true so the existing observatory/, pose-fusion/,
# pointcloud/, nvsim/, and root index.html demos are preserved.
#
# Demos 04 and 05 require a Mixamo "X Bot.fbx" placed in assets/.
# That file is intentionally gitignored (license boundary), so this
# workflow does NOT ship it. Demos 01-03 work standalone; the index
# page documents the FBX requirement honestly.

on:
  push:
    branches: [main]
    paths:
      - 'examples/three.js/**'
      - '.github/workflows/threejs-pages.yml'
  workflow_dispatch:

permissions:
  contents: write

concurrency:
  group: threejs-pages
  cancel-in-progress: true

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout main
        uses: actions/checkout@v4

      - name: Stage demos for Pages
        run: |
          mkdir -p _site/three.js
          # Copy everything except the local Python server (CI doesn't need it)
          # and any stray scratch screenshots.
          cp -r examples/three.js/demos      _site/three.js/demos
          cp -r examples/three.js/screenshots _site/three.js/screenshots
          cp    examples/three.js/README.md   _site/three.js/README.md
          # An index.html that lists the 5 demos with the FBX caveat.
          cp examples/three.js/index.html _site/three.js/index.html
          # Mixamo FBX is gitignored — assets dir won't exist in CI.
          # Drop an empty placeholder so the relative path 'assets/' resolves
          # to a directory listing (404 on missing file) instead of an opaque
          # network error. Browsers showing the 404 path makes the failure
          # visible to anyone trying demos 04/05 without their own FBX.
          mkdir -p _site/three.js/assets
          cat > _site/three.js/assets/README.txt <<'EOF'
          The Mixamo "X Bot.fbx" required by demos 04-skinned-fbx.html and
          05-skinned-realtime.html is intentionally not redistributed here.

          Download your own from https://mixamo.com (FBX Binary, T-Pose,
          Without Skin) and place it here as "X Bot.fbx" if you want to
          run those demos locally. See examples/three.js/README.md in the
          repo for context.
          EOF
          echo "Staged contents:"
          ls -R _site/three.js/ | head -30

      - name: Deploy to GitHub Pages
        uses: peaceiris/actions-gh-pages@v3
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          publish_dir: _site
          # Critical: preserve observatory/, pose-fusion/, pointcloud/, nvsim/
          # and the root index.html already on gh-pages.
          keep_files: true
          commit_message: 'three.js demos: ${{ github.event.head_commit.message }}'