doc-build.yml

name: Build documentation

on:
  pull_request:
  push:
  workflow_dispatch:
    # Allow to run manually

concurrency:
  # Cancel previous runs of this workflow for the same branch
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build-docs:
    runs-on: ubuntu-latest
    container: ghcr.io/sagemath/sage/sage-ubuntu-focal-standard-with-targets:dev
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Update system packages
        run: |
          apt-get update && apt-get install -y git zip

      - name: Add prebuilt tree as a worktree
        id: worktree
        run: |
          set -ex
          git config --global user.email "ci-sage@example.com"
          git config --global user.name "Build & Test workflow"
          git config --global --add safe.directory $(pwd)
          # If actions/checkout downloaded our source tree using the GitHub REST API
          # instead of with git (because do not have git installed in our image),
          # we first make the source tree a repo.
          if [ ! -d .git ]; then git init && git add -A && git commit --quiet -m "new"; fi
          # Tag this state of the source tree "new". This is what we want to build and test.
          git tag -f new
          # Our container image contains a source tree in /sage with a full build of Sage.
          # But /sage is not a git repository.
          # We make /sage a worktree whose index is at tag "new".
          # We then commit the current sources and set the tag "old". (This keeps all mtimes unchanged.)
          # Then we update worktree and index with "git reset --hard new".
          # (This keeps mtimes of unchanged files unchanged and mtimes of changed files newer than unchanged files.)
          # Finally we reset the index to "old". (This keeps all mtimes unchanged.)
          # The changed files now show up as uncommitted changes.
          # The final "git add -N" makes sure that files that were added in "new" do not show
          # as untracked files, which would be removed by "git clean -fx".
          git worktree add --detach worktree-image
          rm -rf /sage/.git && mv worktree-image/.git /sage/
          rm -rf worktree-image && ln -s /sage worktree-image
          if [ ! -f worktree-image/.gitignore ]; then cp .gitignore worktree-image/; fi
          (cd worktree-image && git add -A && git commit --quiet --allow-empty -m "old" -a && git tag -f old && git reset --hard new && git reset --quiet old && git add -N . && git status)
          # Keep track of changes to built HTML
          new_version=$(cat src/VERSION.txt); (cd /sage/local/share/doc/sage/html/en && find . -name "*.html" | xargs sed -i '/class="sidebar-brand-text"/s/Sage [0-9a-z.]* /Sage '$new_version' /'; git init && (echo "*.svg binary"; echo "*.pdf binary") >> .gitattributes && (echo ".buildinfo"; echo '*.inv'; echo '.git*'; echo '*.svg'; echo '*.pdf'; echo '*.png'; echo 'searchindex.js') > .gitignore; git add -A && git commit --quiet -m "old")

      - name: Incremental build
        id: incremental
        run: |
          # Now re-bootstrap and build. The build is incremental because we were careful with the timestamps.
          ./bootstrap && make build
        working-directory: ./worktree-image
        env:
          MAKE: make -j2
          SAGE_NUM_THREADS: 2

      - name: Build (fallback to non-incremental)
        id: build
        if: always() && steps.worktree.outcome == 'success' && steps.incremental.outcome != 'success'
        run: |
          set -ex
          make doc-clean doc-uninstall sagelib-clean && git clean -fx src/sage && ./config.status && make build
        working-directory: ./worktree-image
        env:
          MAKE: make -j2
          SAGE_NUM_THREADS: 2

      - name: Build docs
        id: docbuild
        if: always() && (steps.incremental.outcome == 'success' || steps.build.outcome == 'success')
        # Always non-incremental because of the concern that
        # incremental docbuild may introduce broken links (inter-file references) though build succeeds
        run: |
          set -ex
          mv /sage/local/share/doc/sage/html/en/.git /sage/.git-doc
          make doc-clean doc-uninstall sagelib-clean && git clean -fx src/sage
          mkdir -p /sage/local/share/doc/sage/html/en/ && mv /sage/.git-doc /sage/local/share/doc/sage/html/en/.git
          ./config.status && make doc-html
        working-directory: ./worktree-image
        env:
          MAKE: make -j2
          SAGE_NUM_THREADS: 2

      - name: Copy docs
        id: copy
        if: always() && steps.docbuild.outcome == 'success'
        run: |
          set -ex
          mkdir -p ./docs
          # Create changelog
          echo '## Preview of CHANGES.html'
          (cd /sage/local/share/doc/sage/html/en && git diff --name-only) | tee ./docs/CHANGES.txt
          (cd /sage/local/share/doc/sage/html/en && git diff; rm -rf .git) > ./docs/html.diff
          echo '## Preview of html.diff'; head -n 400 ./docs/html.diff
          (echo '<p><a href="html.diff">HTML diff</a>'; sed -E 's,(.*),<p><a href="\1">\1</a>,' ./docs/CHANGES.txt) > ./docs/CHANGES.html
          # For some reason the deploy step below cannot find /sage/...
          # So copy everything from there to local folder
          # We also need to replace the symlinks because netlify is not following them
          cp -r -L /sage/local/share/doc/sage/html/en/* ./docs
          # Zip everything for increased performance
          zip -r docs.zip docs

      - name: Upload docs
        if: always() && steps.copy.outcome == 'success'
        uses: actions/upload-artifact@v3
        with:
          name: docs
          path: docs.zip