name: publish-image

on:
  workflow_call: {}

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: ${{ github.ref }}   # bei tag-push ist das der Tag-Ref

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Compute tags
        id: meta
        shell: bash
        run: |
          set -euo pipefail
          IMAGE="ghcr.io/${{ github.repository }}"
          RAW_TAG="${{ github.ref_name }}"   # e.g. v1.1.7
          TAG="${RAW_TAG#v}"                 # -> 1.1.7
          echo "tags=$IMAGE:$TAG,$IMAGE:latest" >> "$GITHUB_OUTPUT"

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          file: ./Dockerfile
          push: true
          platforms: linux/amd64,linux/arm64
          tags: ${{ steps.meta.outputs.tags }}
          cache-from: type=gha
          cache-to: type=gha,mode=max