name: Release Docker Image

on:
  push:
    tags: ^v.*

jobs:
  push_to_registries:
    name: Push Docker image to multiple registries
    runs-on: ubuntu-latest
    permissions:
      packages: write
      contents: read
    steps:
      - name: Check out the repo
        uses: actions/checkout@v3

      - name: Log in to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Log in to GHCR
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker tags
        id: meta
        run: |
          version_tag="${{github.ref_name}}"
          tags=($version_tag)
          if [[ "$version_tag" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
            # prerelease tags like `v2.0.0-alpha.1` should not be released as `latest` nor `v2`
            tags+=("latest")
            tags+=($(echo "$version_tag" | cut -d. -f1))
          fi
          releases=""
          for tag in "${tags[@]}"; do
            releases="${releases:+$releases,}offen/docker-volume-backup:$tag,ghcr.io/offen/docker-volume-backup:$tag"
          done
          echo "releases=$releases" >> "$GITHUB_OUTPUT"

      - name: Build and push Docker images
        uses: docker/build-push-action@v4
        with:
          context: .
          push: true
          platforms: linux/amd64,linux/arm64,linux/arm/v7
          tags: ${{ steps.meta.outputs.releases }}