name: Docker - learnGitBranching image

on:
  workflow_dispatch:
  push:
    branches:
      - main  # Trigger CI on main branch
      - bmcclure/main
    paths: 
      - '**/*'
      - '.github/workflows/build-docker.yml'
  pull_request:
    branches:
      - main  # Trigger gated pipeline on PR to main
      - bmcclure/main
    paths:
      - '**/*'
      - '.github/workflows/build-docker.yml'

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push-image:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v3

      - name: Log in to the Container registry
        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
        with:
          tags: |
            type=ref,event=pr
            type=ref,event=branch
            type=sha,format=long
            type=raw,value=latest
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Build Docker image (non main branch)
        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
        if: github.ref != 'refs/heads/bmcclure/main'
        with:
          context: .
          load: true
          push: false
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }} 
      - name: Build and push Docker image (main branch)
        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
        if: github.ref == 'refs/heads/bmcclure/main'
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }} 
      - id: lowercaseImageName
        uses: ASzc/change-string-case-action@v2
        with:
          string: ${{ env.IMAGE_NAME }}
      - name: Save Docker Image archive to local filesystem
        run: "docker save --output learnGitBranching.tar ${{env.REGISTRY}}/${{ steps.lowercaseImageName.outputs.lowercase }}"
      - name: Upload application's Docker Image as pipeline artifact
        uses: actions/upload-artifact@v4
        with:
          path: learnGitBranching.tar
          name: learnGitBranching.tar
