#
name: Create and publish a Docker image to GitHub Container Repository

# Configures this workflow to run every time a change is pushed to a branch, or when main receives a pull request
on:
  push:
  pull_request:
    branches:
      - main

# Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  RUN_TAG: ${{ github.ref_name }}

jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    outputs:
      # Use the first tag produced by docker/metadata-action as the canonical image reference
      safe_run_tag: ${{ fromJSON(steps.meta.outputs.json).tags[0] }}
    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
    permissions:
      contents: read
      packages: write
      attestations: write
      id-token: write
      #
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6

      # Uses the `docker/login-action` action to log in to the Container registry registry using the account and password that will publish the packages. Once published, the packages are scoped to the account defined here.
      - name: Log in to the Container registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Setup QEMU for multi-architecture emulation
      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      # Set up Buildx to allow for multi-platform builds
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
      # The labels it will output are short sha, semantic version (if present), branch, and latest if on main
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=sha
            type=semver,pattern={{version}}
            type=ref,event=branch
            type=raw,value=latest,enable={{is_default_branch}}

      # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
      # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see [Usage](https://github.com/docker/build-push-action#usage) in the README of the `docker/build-push-action` repository.
      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
      - name: Build and push Docker image
        id: push
        uses: docker/build-push-action@v6.18.0
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: linux/amd64
      
      # This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see [Using artifact attestations to establish provenance for builds](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds).
      - name: Generate artifact attestation
        uses: actions/attest-build-provenance@v3
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
          subject-digest: ${{ steps.push.outputs.digest }}
          push-to-registry: true

  test-image:
    runs-on: ubuntu-latest
    needs: build-and-push-image
    env:
      # This is now a full image reference (including registry/repo:tag)
      SAFE_RUN_TAG: ${{ needs.build-and-push-image.outputs.safe_run_tag }}
    steps:
      - name: Log in to the Container registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      # Test the image and notebooks on us-nc-guilford using the simple-entrypoint.sh script, failing if any of the notebooks return an error
      # The RUN environment variable is set to 'test' to trigger the test mode in the simple-entrypoint.sh script
      - name: Test the image and notebooks
        run: |
          docker run --rm \
            -e RUN=test \
            -e LOCALITY=us-nc-guilford \
            "${{ env.SAFE_RUN_TAG }}"