name: Build a new image for the MycroForge docs
run-name: ${{ gitea.actor }} triggered a build for the MycroForge docs image
on: [ push ]

jobs:
  build:
    runs-on: ubuntu-latest
    if: gitea.ref == 'refs/heads/main'
    steps:
      - uses: https://github.com/actions/checkout@v4
      - name: "Build and push Docker image"
        run: |
          IMAGE_NAME="git.devdisciples.com/devdisciples/m4gdocs"
          IMAGE_VERSION="$(cat version.txt)"
          VERSIONED_IMAGE_TAG="$IMAGE_NAME:$IMAGE_VERSION"
          LATEST_IMAGE_TAG="$IMAGE_NAME:latest"

          # Login to the registry
          echo ${{ secrets.DOCKER_PASS }} | docker login git.devdisciples.com --username ${{ secrets.DOCKER_USER }} --password-stdin

          # Check if the image exists.
          # EXISTS = 0 if the image was found else 1.
          EXISTS=$(docker manifest inspect $VERSIONED_TAG > /dev/null 2>&1; echo $?)
          
          # Build a new image and push it if the versioned tag was not found.
          if [[ $EXISTS -eq 1 ]]; then
            docker build -t $VERSIONED_IMAGE_TAG -t $LATEST_IMAGE_TAG .
            docker push $VERSIONED_IMAGE_TAG
            docker push $LATEST_IMAGE_TAG
          # Else notify the user that the image tag already exists and exit with status code 1.
          else
            echo "Image $VERSIONED_TAG already exists, you should probably increment the version."
            exit 1
          fi