---
name: 'Build Docker Images'

on:
  push:
    tags:
      - '**'

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: 'Checkout'
        uses: actions/checkout@v3
      - name: Prepare
        id: prep
        run: |
          DOCKER_IMAGE=${{ secrets.DOCKER_USERNAME }}/${GITHUB_REPOSITORY#*/}

          # If this is git tag, use the tag name as a docker tag
          if [[ $GITHUB_REF == refs/tags/* ]]; then
            VERSION=${GITHUB_REF#refs/tags/}
            TAGS="${DOCKER_IMAGE}:${VERSION}"
          fi
          
          # If this is git branch, use the branch name as a docker tag
          if [[ $GITHUB_REF == refs/heads/* ]]; then
            VERSION=${GITHUB_REF#refs/heads/}
            TAGS="${DOCKER_IMAGE}:${VERSION}"
          fi

          # If the VERSION looks like a version number, assume that
          # this is the most recent version of the image and also
          # tag it 'latest'. This is done by just specifying the ${DOCKER_IMAGE}
          # without a tag.
          if [[ $VERSION =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
            TAGS="$TAGS,${DOCKER_IMAGE}"
          fi

          # Set output parameters.
          echo ::set-output name=tags::${TAGS}
          echo ::set-output name=docker_image::${DOCKER_IMAGE}

      - name: Set up QEMU
        uses: docker/setup-qemu-action@master
        with:
          platforms: all

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

      - name: Login to DockerHub
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Build
        uses: docker/build-push-action@v2
        with:
          builder: ${{ steps.buildx.outputs.name }}
          context: .
          file: ./Dockerfile
          platforms: linux/amd64,linux/arm64,linux/ppc64le
          push: true
          tags: ${{ steps.prep.outputs.tags }}