name: Build Docker Image

on:
  push:
    branches: [ main ]
    paths:
      - 'index.js'
      - 'package.json'
      - 'Dockerfile'
      - '.github/workflows/docker-build.yml'
  pull_request:
    branches: [ main ]
    paths:
      - 'index.js'
      - 'package.json'
      - 'Dockerfile'

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

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Prepare repository variables
        id: prep
        run: |
          echo "REPO_NAME=$(echo ${{ github.repository }} | tr '/' ' ' | awk '{print tolower($2)}')" >> $GITHUB_OUTPUT
          echo "OWNER=$(echo ${{ github.repository_owner }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: |
            ghcr.io/${{ steps.prep.outputs.OWNER }}/${{ steps.prep.outputs.REPO_NAME }}:latest
            ghcr.io/${{ steps.prep.outputs.OWNER }}/${{ steps.prep.outputs.REPO_NAME }}:${{ github.sha }}
          cache-from: type=gha
          cache-to: type=gha,mode=max