name: Publish Docker image

on:
  workflow_dispatch:
  push:
    branches:
      - main
  release:
    types:
      - published

concurrency:
  group: publish-docker-image-${{ github.event.release.tag_name || github.ref }}
  cancel-in-progress: true

permissions:
  contents: read
  packages: write

jobs:
  build:
    runs-on: ${{ matrix.runner }}
    strategy:
      fail-fast: false
      matrix:
        include:
          - platform: linux/amd64
            runner: ubuntu-latest
          - platform: linux/arm64
            runner: ubuntu-24.04-arm
    env:
      BUILD_ARGS: |
        NEXT_PUBLIC_APP_PLATFORM=web
    steps:
      - name: Prepare platform pair
        run: |
          platform=${{ matrix.platform }}
          echo "PLATFORM_PAIR=${platform//\//-}" >> "$GITHUB_ENV"

      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
        with:
          submodules: recursive

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

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

      - name: Docker meta (for labels)
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository_owner }}/readest

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v6
        with:
          context: .
          file: ./Dockerfile
          target: production-stage
          platforms: ${{ matrix.platform }}
          labels: ${{ steps.meta.outputs.labels }}
          build-args: ${{ env.BUILD_ARGS }}
          cache-from: type=registry,ref=ghcr.io/${{ github.repository_owner }}/readest:buildcache-${{ env.PLATFORM_PAIR }}
          cache-to: type=registry,ref=ghcr.io/${{ github.repository_owner }}/readest:buildcache-${{ env.PLATFORM_PAIR }},mode=max
          outputs: type=image,name=ghcr.io/${{ github.repository_owner }}/readest,push-by-digest=true,name-canonical=true,push=true

      - 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@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - name: Download digests
        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

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

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

      - name: Detect Docker Hub credentials
        id: dockerhub
        run: |
          if [ -n "${{ secrets.DOCKERHUB_USERNAME }}" ] && [ -n "${{ secrets.DOCKERHUB_TOKEN }}" ]; then
            echo "enabled=true" >> "$GITHUB_OUTPUT"
          else
            echo "enabled=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Log in to Docker Hub
        if: steps.dockerhub.outputs.enabled == 'true'
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Extract image metadata (GHCR only)
        id: meta-ghcr
        if: steps.dockerhub.outputs.enabled != 'true'
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository_owner }}/readest
          tags: |
            type=raw,value=main,enable={{is_default_branch}}
            type=raw,value=latest,enable=${{ github.event_name == 'release' }}
            type=raw,value=${{ github.event.release.tag_name }},enable=${{ github.event_name == 'release' }}
            type=sha,prefix=sha-

      - name: Extract image metadata (GHCR + Docker Hub)
        id: meta-all
        if: steps.dockerhub.outputs.enabled == 'true'
        uses: docker/metadata-action@v5
        with:
          images: |
            ghcr.io/${{ github.repository_owner }}/readest
            docker.io/${{ secrets.DOCKERHUB_USERNAME }}/readest
          tags: |
            type=raw,value=main,enable={{is_default_branch}}
            type=raw,value=latest,enable=${{ github.event_name == 'release' }}
            type=raw,value=${{ github.event.release.tag_name }},enable=${{ github.event_name == 'release' }}
            type=sha,prefix=sha-

      - name: Create manifest list and push (GHCR only)
        if: steps.dockerhub.outputs.enabled != 'true'
        working-directory: /tmp/digests
        env:
          DOCKER_METADATA_OUTPUT_JSON: ${{ steps.meta-ghcr.outputs.json }}
        run: |
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf 'ghcr.io/${{ github.repository_owner }}/readest@sha256:%s ' *)

      - name: Create manifest list and push (GHCR + Docker Hub)
        if: steps.dockerhub.outputs.enabled == 'true'
        working-directory: /tmp/digests
        env:
          DOCKER_METADATA_OUTPUT_JSON: ${{ steps.meta-all.outputs.json }}
        run: |
          docker buildx imagetools create \
            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf 'ghcr.io/${{ github.repository_owner }}/readest@sha256:%s ' *)

      - name: Published image summary
        run: |
          echo "## Published Images" >> "$GITHUB_STEP_SUMMARY"
          echo "" >> "$GITHUB_STEP_SUMMARY"
          echo "Tags:" >> "$GITHUB_STEP_SUMMARY"
          echo '```' >> "$GITHUB_STEP_SUMMARY"
          if [ "${{ steps.dockerhub.outputs.enabled }}" == "true" ]; then
            echo "${{ steps.meta-all.outputs.tags }}" >> "$GITHUB_STEP_SUMMARY"
          else
            echo "${{ steps.meta-ghcr.outputs.tags }}" >> "$GITHUB_STEP_SUMMARY"
          fi
          echo '```' >> "$GITHUB_STEP_SUMMARY"