name: Build & Publish Docker Image

on:
  push:
    branches: [main]
    tags: ["v*"]
  pull_request:
    branches: [main]
  workflow_dispatch:

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

# Cancel in-progress runs when a new commit is pushed to the same ref.
concurrency:
  group: docker-publish-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build-and-push:
    name: Build & push multi-arch image
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

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

      - name: Set up QEMU (multi-arch)
        uses: docker/setup-qemu-action@v3

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

      # Skip login on PRs from forks — they don't have package:write.
      # Image is built but not pushed in that case.
      - name: Log in to GitHub Container Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Compute image tags & labels
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=raw,value=latest,enable={{is_default_branch}}
            type=sha,prefix=sha-,format=short
          labels: |
            org.opencontainers.image.title=HealthLog
            org.opencontainers.image.description=Self-hosted health-tracking PWA
            org.opencontainers.image.licenses=AGPL-3.0-only
            org.opencontainers.image.source=https://github.com/${{ github.repository }}

      - name: Build & push image
        uses: docker/build-push-action@v6
        with:
          context: .
          file: ./Dockerfile
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
          provenance: true
          sbom: true