name: Publish Docker Image

# Only a release built through "Releases -> New Release" starts a build. A tag
# pushed with plain git does not publish a release and is therefore ignored.
on:
  release:
    types:
      - published

env:
  # Gitea container registry. Set a different host in
  # "Settings -> Actions -> Variables" if the instance ever moves.
  REGISTRY: git.srv.kingeldarion.de
  OWNER: ${{ github.repository_owner }}
  IMAGE: ac-web

jobs:
  docker:
    runs-on: ubuntu-latest
    # This base image makes Docker-in-Docker with Gitea's act-runner painless.
    container:
      image: catthehacker/ubuntu:act-latest

    steps:
      - name: Checkout
        uses: https://github.com/actions/checkout@v4

      - name: Set up QEMU
        uses: https://github.com/docker/setup-qemu-action@v3

      - name: Set up Buildx
        uses: https://github.com/docker/setup-buildx-action@v3

      - name: Login to Gitea Container Registry
        uses: https://github.com/docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.repository_owner }}
          # A personal access token, created in the repo settings as BUILDTOKEN.
          password: ${{ secrets.BUILDTOKEN }}

      - name: Docker meta (tags & labels)
        id: meta
        uses: https://github.com/docker/metadata-action@v5
        with:
          images: |
            ${{ env.REGISTRY }}/${{ env.OWNER }}/${{ env.IMAGE }}
          # Only releases end up here, so every build is the newest one and
          # branch tags can never occur. Move `latest` behind a condition on
          # `github.event.release.prerelease` if pre-releases are used.
          tags: |
            type=raw,value=latest
            type=ref,event=tag
            type=sha,format=short

      # The dockerfile compiles the web bundle itself, so the context is the
      # flutter project and nothing has to be built before this step.
      - name: Build & Push the website image
        uses: https://github.com/docker/build-push-action@v5
        with:
          context: ./ac_web
          file: ./ac_web/Dockerfile
          push: true
          platforms: linux/amd64
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}