docs.yml

name: Docs

# Build the Antora site (with generated operator pages and the
# cross-backend coverage matrix) on every PR, and publish to GitHub
# Pages on pushes to develop. Dokka API bundling is wired in
# commit 6 of the docs-to-Antora migration (see issue #494).

on:
  push:
    branches: [ main, develop ]
    paths:
      - 'docs/**'
      - '.github/workflows/docs.yml'
      - 'build.gradle.kts'
      - 'build-logic/**'
      - 'skainet-lang/skainet-lang-core/**'
  pull_request:
    paths:
      - 'docs/**'
      - '.github/workflows/docs.yml'
      - 'build.gradle.kts'
      - 'build-logic/**'
      - 'skainet-lang/skainet-lang-core/**'
  workflow_dispatch:

concurrency:
  group: docs-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read
  pages: write
  id-token: write

jobs:
  build-docs:
    runs-on: ubuntu-latest
    timeout-minutes: 30

    steps:
      - name: Checkout
        uses: actions/checkout@v6

      # JDK 25 matches the version used by every other workflow in
      # this repo. Runs on the RUNNER, not inside the Docker
      # container, so the Gradle wrapper cache works and generateDocs
      # / dokkaGenerate see the right JDK.
      - name: Set up JDK
        uses: actions/setup-java@v5
        with:
          distribution: temurin
          java-version: '25'

      - name: Cache Gradle
        uses: actions/cache@v5
        with:
          path: |
            ~/.gradle/caches
            ~/.gradle/wrapper
          key: gradle-${{ runner.os }}-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties', '**/libs.versions.toml') }}
          restore-keys: |
            gradle-${{ runner.os }}-

      # Emit the KSP-driven operator fragments and the coverage
      # matrix into docs/modules/ROOT/pages/reference/operators/.
      # Also generate the full Dokka API aggregate so commit 6 can
      # bundle it; running both here means commit 6 is a pure
      # workflow-step + Gradle-task-registration change with no
      # Gradle re-run cost.
      - name: Generate operator docs and Dokka
        run: ./gradlew --no-daemon generateDocs dokkaGenerate

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4

      # The Chromium layer makes the image ~400 MB. First build is
      # ~3–5 minutes; subsequent runs are sub-minute via the GHA
      # cache. Transformers skipped caching here — this workflow
      # improves on that.
      - name: Build Antora image
        uses: docker/build-push-action@v7
        with:
          context: docs/.docker
          tags: skainet-antora:local
          load: true
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Build Antora site
        # Run the container as the runner user (not root) so the
        # files under docs/build/site/ are owned by the same user
        # that the subsequent Gradle `bundleDokkaIntoSite` step runs
        # as. Without this the Copy task fails with
        # "Failed to create directory docs/build/site/api" because
        # the Antora container otherwise writes the site tree as
        # root and Gradle running as runner can't mkdir inside it.
        run: |
          docker run --rm \
            --user "$(id -u):$(id -g)" \
            -v "${{ github.workspace }}:/antora" \
            --workdir /antora/docs \
            skainet-antora:local \
            --stacktrace \
            antora-playbook.yml

      # Bundle Dokka HTML under a sibling `/api/` path of the
      # Antora site. Must run AFTER Antora has populated
      # docs/build/site/, never before — bundleDokkaIntoSite is a
      # plain Copy task that would otherwise pre-create the target
      # directory and the later Antora run would wipe it.
      - name: Bundle Dokka API into site
        run: ./gradlew --no-daemon bundleDokkaIntoSite

      - name: Upload artifact
        uses: actions/upload-pages-artifact@v5
        with:
          path: docs/build/site

  deploy-docs:
    if: github.ref == 'refs/heads/develop' && github.event_name == 'push'
    needs: build-docs
    runs-on: ubuntu-latest
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}

    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v5