name: Docker

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by
# separate terms of service, privacy policy, and support
# documentation.

on:
  schedule:
    - cron: "25 0 * * *"
  push:
    branches: ["main"]
    # Publish semver tags as releases.
    tags: ["v*.*.*"]
  pull_request:
    branches: ["main"]
  workflow_dispatch:

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  test:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write

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

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

      - name: Test
        id: test
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64
          cache-from: type=gha,scope=x64
          pull: true
          cache-to: type=gha,mode=max,scope=x64
          target: test

  build:
    needs: test
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write

    strategy:
      matrix:
        platform: [linux/amd64, linux/arm64]

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

      - name: Prepare variables
        id: vars
        run: |
          SURFIX=$(echo ${{ matrix.platform }} | cut -d'/' -f2)
          echo "SURFIX=$SURFIX" >> $GITHUB_OUTPUT
          # Generate a unique local tag for the image
          echo "LOCAL_TAG=local-${{ github.sha }}-$SURFIX" >> $GITHUB_OUTPUT

      # Set up BuildKit Docker container builder
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      # Extract metadata (tags, labels) for Docker
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
            type=raw,enable=${{ github.ref_type == 'tag' }}, value=latest
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # Build and export Docker image for each platform (without pushing)
      - name: Build Docker image
        id: build
        uses: docker/build-push-action@v6
        with:
          context: .
          pull: true
          push: false
          load: true # Export to local Docker instead of pushing
          tags: ${{ steps.vars.outputs.LOCAL_TAG }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: ${{ matrix.platform }}
          cache-from: type=gha,scope=${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=${{ matrix.platform }}
          build-args: GITHUB_BUILD=true,VERSION=${{ github.ref_type == 'tag' && github.ref_name || github.sha }}
          outputs: type=docker,dest=/tmp/image-${{ steps.vars.outputs.SURFIX }}.tar

      # Upload the tarball as an artifact
      - name: Upload image artifact
        uses: actions/upload-artifact@v4
        with:
          name: docker-image-${{ steps.vars.outputs.SURFIX }}
          path: /tmp/image-${{ steps.vars.outputs.SURFIX }}.tar
          retention-days: 1

  merge-and-push:
    needs: build
    runs-on: ubuntu-latest
    if: github.event_name != 'pull_request'
    permissions:
      contents: read
      packages: write
      id-token: write

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

      # Install the cosign tool
      - name: Install cosign
        uses: sigstore/cosign-installer@v3

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

      # Log into registry
      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract Docker metadata for tagging
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=semver,pattern={{major}}
            type=raw,enable=${{ github.ref_type == 'tag' }}, value=latest
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # Download all image artifacts
      - name: Download AMD64 image
        uses: actions/download-artifact@v4
        with:
          name: docker-image-amd64
          path: /tmp

      - name: Download ARM64 image
        uses: actions/download-artifact@v4
        with:
          name: docker-image-arm64
          path: /tmp

      # Load images into Docker
      - name: Load images
        run: |
          docker load --input /tmp/image-amd64.tar
          docker load --input /tmp/image-arm64.tar

      # Create manifest lists and push
      - name: Create and push manifest lists
        run: |
          TAGS="${{ steps.meta.outputs.tags }}"
          for TAG in $TAGS; do
            # Tag the local images with their registry counterparts
            docker tag local-${{ github.sha }}-amd64 $TAG-amd64
            docker tag local-${{ github.sha }}-arm64 $TAG-arm64

            # Push individual platform images
            # docker push $TAG-amd64
            # docker push $TAG-arm64

            # Create manifest list and push it
            docker buildx imagetools create -t $TAG \
              $TAG-amd64 \
              $TAG-arm64
          done

      # Sign the manifest
      - name: Sign the manifests
        env:
          TAGS: ${{ steps.meta.outputs.tags }}
        run: |
          for TAG in $TAGS; do
            cosign sign --yes $TAG
          done