name: Build Container Images

on:
  schedule:
    - cron: "0 4 * * *"
  workflow_dispatch:

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

jobs:
  discover:
    runs-on: ubuntu-latest
    outputs:
      images: ${{ steps.find.outputs.images }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Find image directories
        id: find
        run: |
          images=$(find . -name Dockerfile -not -path './.github/*' \
            | sed 's|/Dockerfile||; s|^\./||' \
            | jq -R -s -c 'split("\n") | map(select(length > 0))')
          echo "images=${images}" >> "$GITHUB_OUTPUT"

  build:
    needs: discover
    runs-on: ubuntu-latest
    if: ${{ needs.discover.outputs.images != '[]' }}
    permissions:
      contents: read
      packages: write

    strategy:
      fail-fast: false
      matrix:
        image: ${{ fromJson(needs.discover.outputs.images) }}

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

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

      - name: Log into registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-${{ matrix.image }}
          tags: |
            type=raw,value=latest
            type=raw,value={{date 'YYYYMMDD'}}

      - name: Build and push ${{ matrix.image }}
        uses: docker/build-push-action@v5
        with:
          context: ./${{ matrix.image }}
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max