name: Build and push Docker image (amd64, arm64 to hub.docker.com and ghcr.io)

on:
  workflow_dispatch: # allow manual trigger
  push: # build for each branch
    # branches: ["main"]
    paths: # ignore changes to .md files
      - '**'
      - '!*.md'
      # - '!.github/**'
  pull_request: # runs when opened/reopned or when the head branch is updated

permissions:
  contents: read
  packages: write

env:
 BRANCH: ${{ github.head_ref || github.ref_name }} # head_ref/base_ref are only set for PRs, for branches ref_name will be used

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Set environment variables
        run: |
          echo "NOW=$(date -R)" >> $GITHUB_ENV # date -Iseconds; date +'%Y-%m-%dT%H:%M:%S'
          if [[ "$BRANCH" == "main" ]]; then
            echo "IMAGE_TAG=latest" >> $GITHUB_ENV
          else
            echo "IMAGE_TAG=$BRANCH" >> $GITHUB_ENV
          fi
      -
        name: Set up QEMU
        uses: docker/setup-qemu-action@v3
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      -
        name: Login to Docker Hub
        uses: docker/login-action@v3
        # if: ${{ secrets.DOCKERHUB_USERNAME != '' && secrets.DOCKERHUB_TOKEN != '' }} # does not work: Unrecognized named-value: 'secrets' - https://www.cloudtruth.com/blog/skipping-jobs-in-github-actions-when-secrets-are-unavailable-securely-inject-configuration-secrets-into-github
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      -
        name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }} # actor is user that opened PR, was repository_owner before
          password: ${{ secrets.GITHUB_TOKEN }}
      -
        name: Build and push
        uses: docker/build-push-action@v6
        if: ${{ env.IMAGE_TAG != '' }}
        with:
          context: .
          push: ${{ secrets.DOCKERHUB_USERNAME != '' }}
          build-args: |
            COMMIT=${{ github.sha }}
            BRANCH=${{ env.BRANCH }}
            NOW=${{ env.NOW }}
          platforms: linux/amd64,linux/arm64
          tags: |
            ${{ secrets.DOCKERHUB_USERNAME }}/free-games-claimer:${{env.IMAGE_TAG}}
            ghcr.io/${{ github.actor }}/free-games-claimer:${{env.IMAGE_TAG}}
          cache-from: type=gha
          cache-to: type=gha,mode=max