name: Build and Push Docker Image

on:
  push:
    branches: [main]
  workflow_dispatch:

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

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

    steps:
      - name: Checkout
        uses: actions/checkout@v7

      - name: Log in to GHCR
        uses: docker/login-action@v4
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4

      - name: Build and push
        uses: docker/build-push-action@v7
        with:
          context: .
          push: true
          tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
          cache-from: type=gha
          cache-to: type=gha,mode=max

  cleanup-old-images:
    needs: build-and-push
    runs-on: ubuntu-latest
    permissions:
      packages: write

    steps:
      - name: Delete old, untagged image versions
        uses: actions/delete-package-versions@v5
        with:
          package-name: ${{ github.event.repository.name }}
          package-type: container
          min-versions-to-keep: 4
          delete-only-untagged-versions: true