name: Release multi-arch container image

on:
  workflow_dispatch:
  push:
    branches:
      - main
      - "test/**"
  schedule:
    - cron: "0 0 * * *" # Run every day at 00:00 UTC.

env:
  REGISTRY: ghcr.io/${{ github.repository_owner }}
  REGISTRY_USER: ${{ github.actor }}
  REGISTRY_PASSWORD: ${{ github.token }}
  IMAGE_NAME: dangerzone/dangerzone

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64
    steps:
      - uses: actions/checkout@v4

      - name: Get current date
        id: date
        run: echo "date=$(date +'%Y%m%d')" >> $GITHUB_OUTPUT

      - name: Prepare
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> $GITHUB_ENV

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

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

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

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

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v6
        with:
          context: ./dangerzone/
          file: Dockerfile
          build-args: |
            DEBIAN_ARCHIVE_DATE=${{ steps.date.outputs.date }}
          ## Remove potentially incorrect Docker provenance.
          #provenance: false
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          outputs: type=image,"name=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}",push-by-digest=true,name-canonical=true,push=true

      - name: Export digest
        run: |
          mkdir -p ${{ runner.temp }}/digests
          digest="${{ steps.build.outputs.digest }}"
          touch "${{ runner.temp }}/digests/${digest#sha256:}"

      - name: Upload digest
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: ${{ runner.temp }}/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: ubuntu-latest
    needs:
      - build
    outputs:
      digest: ${{ steps.image.outputs.digest }}
      image: ${{ steps.image.outputs.image }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Compute image tag
        id: tag
        run: |
          DATE=$(date +'%Y%m%d')
          TAG=$(git describe --long --first-parent | tail -c +2)
          echo "tag=${DATE}-${TAG}" >> $GITHUB_OUTPUT

      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: ${{ runner.temp }}/digests
          pattern: digests-*
          merge-multiple: true

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

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

      #- name: Docker meta
      #  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}}

      - name: Create manifest list and push
        working-directory: ${{ runner.temp }}/digests
        run: |
          IMAGE=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.tag.outputs.tag }}
          DIGESTS=$(printf '${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@sha256:%s ' *)
          docker buildx imagetools create -t ${IMAGE} ${DIGESTS}

      - name: Inspect image
        id: image
        run: |
          # NOTE: Set the image as an output because the `env` context is not
          # available to the inputs of a reusable workflow call.
          image_name="${REGISTRY}/${IMAGE_NAME}"
          echo "image=$image_name" >> "$GITHUB_OUTPUT"
          docker buildx imagetools inspect ${image_name}:${{ steps.tag.outputs.tag }}
          digest=$(docker buildx imagetools inspect ${image_name}:${{ steps.tag.outputs.tag }} --format "{{json .Manifest}}" | jq -r '.digest')
          echo "digest=$digest" >> "$GITHUB_OUTPUT"

  # This step calls the container workflow to generate provenance and push it to
  # the container registry.
  provenance:
    needs:
      - merge
    permissions:
      actions: read # for detecting the Github Actions environment.
      id-token: write # for creating OIDC tokens for signing.
      packages: write # for uploading attestations.
    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_container_slsa3.yml@v2.0.0
    with:
      digest: ${{ needs.merge.outputs.digest }}
      image: ${{ needs.merge.outputs.image }}
      registry-username: ${{ github.actor }}
    secrets:
      registry-password: ${{ secrets.GITHUB_TOKEN }}