name: Docker Build Split

on:
  push:
    branches:
      - 3.23
  workflow_dispatch:

env:
  # Das Ziel-Repo (Das saubere Repo)
  IMAGE_NAME: git.pi-farm.de/pi-farm/docker-baseimage-alpine
  # Das Cache-Repo (Für die Zwischen-Images) - MUSS IN GITEA EXISTIEREN
  CACHE_IMAGE_NAME: git.pi-farm.de/pi-farm/docker-baseimage-alpine-cache

jobs:
  build:
    name: Build amd64 & arm64 separately
    runs-on: buildx-multiarch

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set image tag from branch
        run: |
          VERSION=$(git rev-parse --abbrev-ref HEAD)
          if [ -z "$VERSION" ]; then
            echo "ERROR: could not determine branch name"
            exit 1
          fi
          echo "VERSION=$VERSION" >> $GITEA_ENV
          echo "BUILD_DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> $GITEA_ENV

      - name: Login to registry
        run: |
          echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login \
            git.pi-farm.de \
            -u ${{ secrets.REGISTRY_USER }} \
            --password-stdin
      
      - name: Setup buildx
        run: |
          docker buildx rm multiarch || true
          docker buildx create \
            --name multiarch \
            --driver docker-container \
            --use
          docker buildx inspect --bootstrap
                            
      # SCHRITT 1: AMD64 bauen -> In das CACHE Repo pushen
      - name: Build & push amd64 (Cache)
        run: |
          docker buildx build \
            --platform linux/amd64 \
            -f Dockerfile \
            --build-arg BUILD_DATE=${BUILD_DATE} \
            --build-arg VERSION=${VERSION} \
            -t ${CACHE_IMAGE_NAME}:${VERSION}-amd64 \
            --push \
            .

      # SCHRITT 2: ARM64 bauen -> In das CACHE Repo pushen
      - name: Build & push arm64 (Cache)
        run: |
          docker buildx build \
            --platform linux/arm64 \
            -f Dockerfile.aarch64 \
            --build-arg BUILD_DATE=${BUILD_DATE} \
            --build-arg VERSION=${VERSION} \
            -t ${CACHE_IMAGE_NAME}:${VERSION}-arm64 \
            --push \
            .

      # SCHRITT 3: Manifest erstellen -> In das PROD Repo pushen
      # Hier geschieht die Magie: Wir nehmen die Quellen aus dem Cache-Repo
      # und erstellen das Manifest im Prod-Repo.
      - name: Create and push manifest to Prod
        run: |
          docker buildx imagetools create \
            -t ${IMAGE_NAME}:${VERSION} \
            ${CACHE_IMAGE_NAME}:${VERSION}-amd64 \
            ${CACHE_IMAGE_NAME}:${VERSION}-arm64