name: Build Docker

permissions:
  actions: read
  contents: read
  packages: write

on:
  push:
    branches:
      - master
  pull_request:
    branches:
      - master
    paths:
      - '.github/workflows/docker-release.yml'
      - 'Dockerfile'
  release:
    types:
      - released    # publishing of stable releases

# Cancel earlier, unfinished runs of this workflow on the same branch (unless on release)
concurrency:
  group: "${{ github.workflow }} @ ${{ github.ref_name }}"
  cancel-in-progress: ${{ github.event_name != 'release' }}

env:
  IMAGE_NAME: ghcr.io/cockatrice/servatrice
  OCI_DESCRIPTION: Server for Cockatrice, a cross-platform virtual tabletop for multiplayer card games
  OCI_TITLE: Servatrice
  OCI_URL: https://cockatrice.github.io/

jobs:
  build:
    strategy:
      fail-fast: false
      matrix:
        include:
          - platform: linux/amd64
            runner: ubuntu-latest

          - platform: linux/arm64
            runner: ubuntu-24.04-arm

    name: "Build (${{ matrix.platform }})"
    if: github.repository_owner == 'Cockatrice'
    runs-on: ${{ matrix.runner }}

    steps:
      - name: "Checkout"
        uses: actions/checkout@v7

      - name: "Set up Docker buildx"
        uses: docker/setup-buildx-action@v4

      - name: "Login to GitHub Container Registry (GHCR)"
        if: github.event_name == 'release' && github.event.release.prerelease == false
        id: login
        uses: docker/login-action@v4
        with:
          password: ${{ github.token }}
          registry: ghcr.io
          username: ${{ github.actor }}

      - name: "Build Docker image and push by digest"
        if: steps.login.outcome == 'success'
        id: build
        uses: docker/build-push-action@v7
        with:
          cache-from: type=gha,scope=servatrice-${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=servatrice-${{ matrix.platform }}
          context: .
          labels: |
            org.opencontainers.image.description=${{ env.OCI_DESCRIPTION }}
            org.opencontainers.image.title=${{ env.OCI_TITLE }}
            org.opencontainers.image.url=${{ env.OCI_URL }}
          outputs: type=image,push-by-digest=true,name-canonical=true,push=true
          platforms: ${{ matrix.platform }}

      - name: "Build Docker image"
        if: steps.login.outcome != 'success'
        uses: docker/build-push-action@v7
        with:
          cache-from: type=gha,scope=servatrice-${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=servatrice-${{ matrix.platform }}
          context: .
          platforms: ${{ matrix.platform }}
          push: false

      - name: Export digest
        if: steps.login.outcome == 'success'
        env:
          DIGEST: ${{ steps.build.outputs.digest }}
        run: |
          mkdir -p $RUNNER_TEMP/digests
          touch "$RUNNER_TEMP/digests/${DIGEST#sha256:}"

      - uses: actions/upload-artifact@v7
        if: steps.login.outcome == 'success'
        with:
          name: digest-${{ matrix.platform }}
          path: $RUNNER_TEMP/digests/*
          retention-days: 1


  merge:
    needs: build
    name: "Publish manifest"
    if: github.repository_owner == 'Cockatrice' && github.event_name == 'release' && github.event.release.prerelease == false
    runs-on: ubuntu-slim

    steps:
      - uses: actions/download-artifact@v4
        with:
          path: $RUNNER_TEMP/digests
          pattern: digest-*
          merge-multiple: true

      - name: "Set up Docker buildx"
        uses: docker/setup-buildx-action@v4

      - name: "Login to GitHub Container Registry (GHCR)"
        uses: docker/login-action@v4
        with:
          password: ${{ github.token }}
          registry: ghcr.io
          username: ${{ github.actor }}

      - name: "Docker metadata"
        id: metadata
        uses: docker/metadata-action@v6
        with:
          images: ${{ env.IMAGE_NAME }}
          tags: |
            type=raw,value=latest
            type=ref,event=tag

      - name: "Create manifest"
        env:
          TAGS: ${{ steps.metadata.outputs.tags }}
        working-directory: ${{ runner.temp }}/digests
        run: |
          TAG_ARGS=""
          for tag in $TAGS; do
            TAG_ARGS="$TAG_ARGS -t $tag"
          done

          docker buildx imagetools create \
            --annotation "index:org.opencontainers.image.description=$OCI_DESCRIPTION" \
            --annotation "index:org.opencontainers.image.title=$OCI_TITLE" \
            --annotation "index:org.opencontainers.image.url=$OCI_URL" \
            $TAG_ARGS \
            $(printf '%s@sha256:%s ' "$IMAGE_NAME" *)

      - name: "Inspect image"
        run: docker buildx imagetools inspect "$IMAGE_NAME:latest"