name: Deploy RC preview to GitHub Pages

on:
  push:
    tags: ["rc*"]
  workflow_dispatch:

permissions:
  contents: write

jobs:
  deploy-rc-pages:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout (tag)
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.11"

      - name: Install dependencies
        run: |
          set -euo pipefail
          pip install -r mkdocs/requirements.txt

      - name: Build site (strict default)
        run: |
          set -euo pipefail
          export MKDOCS_STRICT="${MKDOCS_STRICT:-true}"
          export TMPDIR="${RUNNER_TEMP:-$TMPDIR}"
          export OUTPUT_DIR="${OUTPUT_DIR:-${TMPDIR}/dist/}"
          tools/build.sh --config mkdocs/mkdocs.yml

      - name: Checkout gh-pages branch
        run: |
          set -euo pipefail
          git fetch origin gh-pages:gh-pages || true
          if git show-ref --verify --quiet refs/heads/gh-pages; then
            git switch gh-pages
          else
            git switch --orphan gh-pages
            rm -rf ./*
            git config user.name "github-actions[bot]"
            git config user.email "github-actions[bot]@users.noreply.github.com"
            git commit --allow-empty -m "Initialize gh-pages"
          fi

      - name: Publish RC preview under /rc/<tag>/
        run: |
          export TMPDIR="${RUNNER_TEMP:-$TMPDIR}"
          export OUTPUT_DIR="${OUTPUT_DIR:-${TMPDIR}/dist/}"

          set -euo pipefail
          rm -rf "rc"* || true
          mkdir -p "rc/"
          cp -a "$OUTPUT_DIR/." "rc/"

          git add -A
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git commit -m "Deploy RC preview ${GITHUB_REF_NAME}" || echo "No changes to commit"
          git push origin gh-pages
      - name: Publish prerelease (GitHub)
        uses: softprops/action-gh-release@v2
        with:
          prerelease: true
          body: |
            RC preview: https://<org>.github.io/<repo>/rc/

          Tag: ${{ github.ref_name }}
          Commit: ${{ github.sha }}