name: Build and deploy MkDocs to GitHub Pages

on:
  push:
    branches:
      - master
  release:
    types: [ published ]

jobs:
  docs:
    if: github.repository == 'Kotlin/dokka'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          path: dokka
      - uses: dorny/paths-filter@v2
        id: filter
        with:
          filters: |
            mkdocs_changed:
              - 'mkdocs/**'
          working-directory: ./dokka
      - uses: actions/setup-java@v3
        with:
          distribution: 'zulu'
          java-version: 17
          cache: 'maven'
      - uses: gradle/gradle-build-action@v2
        with:
          gradle-home-cache-cleanup: true
      - name: Get current dokka version
        run: echo "DOKKA_VERSION=`./gradlew :properties | grep '^version:.*' | cut -d ' ' -f 2`" >> $GITHUB_ENV
        if: github.event_name == 'release' || steps.filter.outputs.mkdocs_changed == 'true'
        working-directory: ./dokka
      - name: Build docs
        run: ./gradlew mkdocsBuild -Pdokka_version=$DOKKA_VERSION --info
        if: github.event_name == 'release' || steps.filter.outputs.mkdocs_changed == 'true'
        working-directory: ./dokka
      - name: Deploy
        uses: peaceiris/actions-gh-pages@v3
        if: github.event_name == 'release' || steps.filter.outputs.mkdocs_changed == 'true'
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          publish_dir: ./dokka/mkdocs/build/mkdocs
          keep_files: true
          full_commit_message: Publish ${{ env.DOKKA_VERSION }} documentation