#  based on https://blog.oddbit.com/post/2020-09-25-building-multi-architecture-im/
---
# Interlisp workflow to build Docker Image that support multiple architectures
name: Build Medley Docker image

# Run this workflow on demand
on:
  workflow_dispatch:

# Jobs that compose this workflow
jobs:
  # Job to build the docker image
  docker:
    runs-on: ubuntu-latest
    steps:
      # Checkout the branch
      - name: Checkout
        uses: actions/checkout@v2

      # Get the Medley Release Information
      - name: Get Medley Release Information
        id: medley_version
        uses: abatilo/release-info-action@v1.3.0
        with:
          owner: Interlisp
          repo: medley

      # Get the Maiko Release Information
      - name: Get Maiko Release Information
        id: maiko_version
        uses: abatilo/release-info-action@v1.3.0
        with:
          owner: Interlisp
          repo: maiko

      # Setup needed environment variables
      - name: Prepare
        id: prep
        run: |
          DOCKERHUB_ACCOUNT=interlisp
          DOCKER_IMAGE=${DOCKERHUB_ACCOUNT}/${GITHUB_REPOSITORY#*/}
          VERSION=latest
          MAIKO_RELEASE=${{ steps.maiko_version.outputs.latest_tag }}
          MEDLEY_RELEASE=${{ steps.medley_version.outputs.latest_tag }}

          TAGS="${DOCKER_IMAGE}:${MEDLEY_RELEASE},${DOCKER_IMAGE}:${VERSION},${DOCKER_IMAGE}:${MAIKO_RELEASE}"
          
          # Set output parameters.
          echo ::set-output name=tags::${TAGS}
          echo ::set-output name=docker_image::${DOCKER_IMAGE}
          echo ::set-output name=build_time::$(date -u +'%Y-%m-%dT%H:%M:%SZ')
          echo ::set-output name=version::${VERSION}
          echo ::set-output name=maiko_release::${MAIKO_RELEASE}
          echo ::set-output name=medley_release::${MEDLEY_RELEASE}

      # Download Medley Release Assets
      - name: Download Release Assets
        uses: robinraju/release-downloader@v1.2
        with:
          repository: Interlisp/medley
          token: ${{ secrets.GITHUB_TOKEN }}
          latest: true
          fileName: "*"

      # Download Maiko Release Assets
      - name: Download Release Assets
        uses: robinraju/release-downloader@v1.2
        with:
          repository: Interlisp/maiko
          token: ${{ secrets.GITHUB_TOKEN }}
          latest: true
          fileName: "*"

      # Setup Docker Machine Emulation environment
      - name: Set up QEMU
        uses: docker/setup-qemu-action@master
        with:
          platforms: all

      # Setup Docker Buildx function
      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@master

      # Login to DockerHub - required to store the image
      - name: Login to DockerHub
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v1
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      # Start the Docker Build using the Dockerfilein the repository
      - name: Build
        uses: docker/build-push-action@v2
        with:
          builder: ${{ steps.buildx.outputs.name }}
          context: .
          file: ./Dockerfile
          # Platforms
          #  linux/amd64 -- Standard x86_64
          #  linux/arm64 -- Apple M1
          #  linux/arm/v7 -- Raspberry pi
          platforms: linux/amd64,linux/arm64,linux/arm/v7
          # Push the created image
          push: true
          # tags to assign to the Docker image
          tags: ${{ steps.prep.outputs.tags }}
          build-args: |
            medley_release=${{steps.prep.outputs.medley_release}}
            maiko_release=${{steps.prep.outputs.maiko_release}}
            build_date=${{steps.prep.outputs.build_time}}