name: CI

on:
  pull_request:
    paths-ignore:
      - '**/*.md'
      - 'README*'
      - 'LICENSE*'
      - 'shell.nix*'
  push:
    branches:
      - master
    paths-ignore:
      - '**/*.md'
      - 'README*'
      - 'LICENSE*'
      - 'shell.nix*'

jobs:
  build:
    timeout-minutes: 10
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          lfs: false

      - name: Set up JDK
        uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: '17'
          cache: maven

      - name: Build and test
        run: mvn -B verify

  docker:
    timeout-minutes: 10
    runs-on: ubuntu-latest
    needs: build
    outputs:
      pom_version: ${{ steps.read_version.outputs.pom_version }}
      version_changed: ${{ steps.version_check.outputs.version_changed }}
    steps:
      - uses: actions/checkout@v4
        with:
          lfs: true

      - name: Check for pom.xml changes
        id: version_check
        run: |
          if [ "${{ github.event_name }}" != "push" ]; then
            echo "version_changed=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          if git diff --name-only "${{ github.event.before }}" "${{ github.sha }}" -- pom.xml | grep -q '^pom.xml$'; then
            echo "version_changed=true" >> "$GITHUB_OUTPUT"
          else
            echo "version_changed=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Read pom.xml version
        id: read_version
        run: |
          VERSION=$(mvn -q -DforceStdout help:evaluate -Dexpression=project.version)
          echo "pom_version=$VERSION" >> "$GITHUB_OUTPUT"

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Set Docker tags
        id: docker_tags
        run: |
          TAGS="kruhlmann/imgfloat-j:latest,kruhlmann/imgfloat-j:${{ github.sha }}"
          if [ "${{ steps.version_check.outputs.version_changed }}" = "true" ]; then
            TAGS="$TAGS,kruhlmann/imgfloat-j:${{ steps.read_version.outputs.pom_version }}"
          fi
          echo "tags=$TAGS" >> "$GITHUB_OUTPUT"

      - name: Log in to Docker Hub
        if: github.event_name == 'push' && github.ref == 'refs/heads/master'
        uses: docker/login-action@v3
        with:
          username: kruhlmann
          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
          tags: ${{ steps.docker_tags.outputs.tags }}

  release:
    timeout-minutes: 10
    runs-on: ubuntu-latest
    needs: docker
    if: github.event_name == 'push' && github.ref == 'refs/heads/master' && needs.docker.outputs.version_changed == 'true'
    steps:
      - uses: actions/checkout@v4
        with:
          lfs: false

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          tag_name: v${{ needs.docker.outputs.pom_version }}
          name: v${{ needs.docker.outputs.pom_version }}
          generate_release_notes: true