name: Reusable check HTML IDs

on:
  workflow_call:

permissions: {}

env:
  FORCE_COLOR: 1

jobs:
  check-html-ids:
    name: 'Check for removed HTML IDs'
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - name: 'Check out PR head'
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          persist-credentials: false
          ref: ${{ github.event.pull_request.head.sha }}
      - name: 'Find merge base'
        id: merge-base
        run: |
          BASE="${{ github.event.pull_request.base.sha }}"
          HEAD="${{ github.event.pull_request.head.sha }}"
          git fetch --depth=$((${{ github.event.pull_request.commits }} + 10)) --no-tags origin "$BASE" "$HEAD"

          if ! MERGE_BASE=$(git merge-base "$BASE" "$HEAD" 2>/dev/null); then
            git fetch --deepen=1 --no-tags origin "$BASE" "$HEAD"

            OLDEST=$(git rev-list --reflog --max-parents=0 --reverse "${BASE}^" "${HEAD}^" | head -1)
            TIMESTAMP=$(git show --format=%at --no-patch "$OLDEST")

            git fetch --shallow-since="$TIMESTAMP" --no-tags origin "$BASE" "$HEAD"

            MERGE_BASE=$(git merge-base "$BASE" "$HEAD")
          fi
          echo "sha=$MERGE_BASE" >> "$GITHUB_OUTPUT"
      - name: 'Create worktree at merge base'
        env:
          MERGE_BASE: ${{ steps.merge-base.outputs.sha }}
        run: git worktree add /tmp/merge-base "$MERGE_BASE" --detach
      - name: 'Set up Python'
        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          python-version: '3'
          cache: 'pip'
          cache-dependency-path: 'Doc/requirements.txt'
      - name: 'Install build dependencies'
        run: make -C /tmp/merge-base/Doc/ venv
      - name: 'Build HTML documentation'
        run: make -C /tmp/merge-base/Doc/ SPHINXOPTS="--quiet" html
      - name: 'Collect HTML IDs'
        run: python Doc/tools/check-html-ids.py collect /tmp/merge-base/Doc/build/html -o /tmp/html-ids-base.json.gz
      - name: 'Download PR head HTML IDs'
        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
        with:
          name: html-ids-head.json.gz
          path: /tmp
      - name: 'Check for removed HTML IDs'
        run: |
          # shellcheck disable=SC2046
          python Doc/tools/check-html-ids.py -v check \
            /tmp/html-ids-base.json.gz /tmp/html-ids-head.json.gz \
            $([ -f Doc/tools/removed-ids.txt ] && echo "--exclude-file Doc/tools/removed-ids.txt")