name: Documentation
on:
  push:
    branches-ignore:
      - 'translations**'
  pull_request:
  workflow_dispatch:
concurrency:
  group: docs-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: true
permissions:
  contents: read
  pages: write
  id-token: write
env:
  DEFAULT_UV_VERSION: "0.10.x"
  DEFAULT_PYTHON_VERSION: "3.12"
jobs:
  changes:
    name: Detect Docs Changes
    runs-on: ubuntu-slim
    outputs:
      docs_changed: ${{ steps.force.outputs.run_all == 'true' || steps.filter.outputs.docs == 'true' }}
    steps:
      - name: Checkout
        uses: actions/checkout@v6.0.2
        with:
          fetch-depth: 0
      - name: Decide run mode
        id: force
        run: |
          if [[ "${{ github.event_name }}" == "workflow_dispatch" ]]; then
            echo "run_all=true" >> "$GITHUB_OUTPUT"
          elif [[ "${{ github.event_name }}" == "push" && ( "${{ github.ref_name }}" == "main" || "${{ github.ref_name }}" == "dev" ) ]]; then
            echo "run_all=true" >> "$GITHUB_OUTPUT"
          else
            echo "run_all=false" >> "$GITHUB_OUTPUT"
          fi
      - name: Set diff range
        id: range
        if: steps.force.outputs.run_all != 'true'
        run: |
          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
            echo "base=${{ github.event.pull_request.base.sha }}" >> "$GITHUB_OUTPUT"
          elif [[ "${{ github.event.created }}" == "true" ]]; then
            echo "base=${{ github.event.repository.default_branch }}" >> "$GITHUB_OUTPUT"
          else
            echo "base=${{ github.event.before }}" >> "$GITHUB_OUTPUT"
          fi
          echo "ref=${{ github.sha }}" >> "$GITHUB_OUTPUT"
      - name: Detect changes
        id: filter
        if: steps.force.outputs.run_all != 'true'
        uses: dorny/paths-filter@v3.0.2
        with:
          base: ${{ steps.range.outputs.base }}
          ref: ${{ steps.range.outputs.ref }}
          filters: |
            docs:
              - 'docs/**'
              - 'zensical.toml'
              - 'pyproject.toml'
              - 'uv.lock'
              - '.github/workflows/ci-docs.yml'
  build:
    needs: changes
    if: needs.changes.outputs.docs_changed == 'true'
    name: Build Documentation
    runs-on: ubuntu-24.04
    steps:
      - uses: actions/configure-pages@v5.0.0
      - name: Checkout
        uses: actions/checkout@v6.0.2
      - name: Set up Python
        id: setup-python
        uses: actions/setup-python@v6.2.0
        with:
          python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
      - name: Install uv
        uses: astral-sh/setup-uv@v7.3.1
        with:
          version: ${{ env.DEFAULT_UV_VERSION }}
          enable-cache: true
          python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
      - name: Install Python dependencies
        run: |
          uv sync --python ${{ steps.setup-python.outputs.python-version }} --dev --frozen
      - name: Build documentation
        run: |
          uv run \
            --python ${{ steps.setup-python.outputs.python-version }} \
            --dev \
            --frozen \
            zensical build --clean
      - name: Upload GitHub Pages artifact
        uses: actions/upload-pages-artifact@v4.0.0
        with:
          path: site
          name: github-pages-${{ github.run_id }}-${{ github.run_attempt }}
  deploy:
    name: Deploy Documentation
    needs: [changes, build]
    if: github.event_name == 'push' && github.ref == 'refs/heads/main' && needs.changes.outputs.docs_changed == 'true'
    runs-on: ubuntu-24.04
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    steps:
      - name: Deploy GitHub Pages
        uses: actions/deploy-pages@v4.0.5
        id: deployment
        with:
          artifact_name: github-pages-${{ github.run_id }}-${{ github.run_attempt }}
  gate:
    name: Docs CI Gate
    needs: [changes, build]
    if: always()
    runs-on: ubuntu-slim
    steps:
      - name: Check gate
        run: |
          if [[ "${{ needs.changes.outputs.docs_changed }}" != "true" ]]; then
            echo "No docs-relevant changes detected."
            exit 0
          fi

          if [[ "${{ needs.build.result }}" != "success" ]]; then
            echo "::error::Docs build job result: ${{ needs.build.result }}"
            exit 1
          fi

          echo "Docs checks passed."