---
name: Build container image

on:
  workflow_dispatch:
  push:
    branches: [ main ]
    tags: [ '*' ]
  pull_request:
    paths:
      - .github/workflows/build-image.yml
      - Containerfile

jobs:
  build-image:
    runs-on: ubuntu-latest

    concurrency:
      group: ${{ github.ref }}
      cancel-in-progress: true

    steps:
      - uses: actions/checkout@v3.3.0

      - name: Discover build-time variables
        run: |
          echo "RUBY_VERSION=$(cat .ruby-version)" >> $GITHUB_ENV
          echo "BUNDLER_VERSION=$(egrep -A1 "^BUNDLED WITH" Gemfile.lock | tr -d '\n' | awk '{ print $3; }')" >> $GITHUB_ENV
          case "${{ github.ref_name }}" in
          */merge)
            # use commit id as version for pull requests
            echo "RETROSPRING_VERSION=${{ github.sha }}" >> $GITHUB_ENV
            ;;
          *)
            # use tags and branches as version otherwise
            echo "RETROSPRING_VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
            ;;
          esac

      - name: Login to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
        if: github.event_name != 'pull_request'

      - name: Build and push
        uses: docker/build-push-action@v4
        with:
          build-args: |
            BUNDLER_VERSION=${{ env.BUNDLER_VERSION }}
            RETROSPRING_VERSION=${{ env.RETROSPRING_VERSION }}
            RUBY_VERSION=${{ env.RUBY_VERSION }}
          context: .
          file: Containerfile
          push: ${{ github.event_name != 'pull_request' }}
          tags: retrospring/retrospring:${{ env.RETROSPRING_VERSION }}