name: Build Base Runner Image

on:
  push:
    paths:
      - 'Dockerfile.builder'
      - '.gitea/workflows/build-builder.yml'
  workflow_dispatch:

jobs:
  build-builder:
    strategy:
      matrix:
        include:
          - platform: linux/amd64
            runner: linux-amd64
          - platform: linux/arm64
            runner: linux-arm64
    runs-on: ${{ matrix.runner }}
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

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

      - name: Login to Gitea Container Registry
        uses: docker/login-action@v3
        with:
          registry: git.nicola.sh
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Build and push builder by digest
        id: build
        uses: docker/build-push-action@v5
        with:
          context: .
          file: Dockerfile.builder
          platforms: ${{ matrix.platform }}
          outputs: type=image,name=git.nicola.sh/public/nicotine-less-builder,push-by-digest=true,name-canonical=true,push=true
          cache-from: type=registry,ref=git.nicola.sh/public/nicotine-less-builder:buildcache-${{ matrix.platform }}
          cache-to: type=registry,ref=git.nicola.sh/public/nicotine-less-builder:buildcache-${{ matrix.platform }},mode=max

      - name: Export digest
        run: |
          mkdir -p /tmp/digests
          digest="${{ steps.build.outputs.digest }}"
          touch "/tmp/digests/${digest#sha256:}"

      - name: Upload digest
        uses: actions/upload-artifact@v4
        with:
          name: digests-builder-${{ matrix.platform }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge-builder:
    needs: build-builder
    runs-on: linux-amd64
    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-builder-*
          merge-multiple: true

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

      - name: Login to Gitea Container Registry
        uses: docker/login-action@v3
        with:
          registry: git.nicola.sh
          username: ${{ secrets.REGISTRY_USERNAME }}
          password: ${{ secrets.REGISTRY_PASSWORD }}

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create \
            -t git.nicola.sh/public/nicotine-less-builder:latest \
            $(printf 'git.nicola.sh/public/nicotine-less-builder@sha256:%s ' *)