name: Build Docker Image

on:
  push:
    branches:
      - main
    tags:
      - 'v*'
    paths-ignore:
      - '**.md'
      - '.github/**'
      - '!.github/workflows/docker-build.yml'
  pull_request:
    branches:
      - main
    paths-ignore:
      - '**.md'
  workflow_dispatch:

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

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

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      
    strategy:
      fail-fast: false
      matrix:
        platform:
          - linux/amd64
          - linux/arm64

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

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

      - name: Log in to Container Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build and push Docker image
        id: build
        uses: docker/build-push-action@v5
        with:
          context: .
          file: ./Dockerfile
          platforms: ${{ matrix.platform }}
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha,scope=${{ github.ref_name }}-${{ matrix.platform }}
          cache-to: type=gha,mode=max,scope=${{ github.ref_name }}-${{ matrix.platform }}

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

      - name: Upload digest
        if: github.event_name != 'pull_request'
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ strategy.job-index }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    needs: build
    if: github.event_name != 'pull_request'
    
    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

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

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

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf '${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@sha256:%s ' *)

      - name: Inspect image
        run: |
          docker buildx imagetools inspect ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.meta.outputs.version }}

  test:
    runs-on: ubuntu-latest
    needs: build
    if: always()

    steps:
      - name: Docker Build Summary
        run: |
          echo "🐳 Docker build completed!"
          echo "📦 Multi-platform support: linux/amd64, linux/arm64"
          echo "🔄 Cache optimization enabled"
          if [ "${{ github.event_name }}" != "pull_request" ]; then
            echo "🚀 Images pushed to GitHub Container Registry"
            echo "📋 Available tags:"
            echo "  - latest (from main branch)"
            echo "  - version tags (from git tags)"
            echo "  - branch names (from pushes)"
          else
            echo "🧪 Build test completed (no push for PR)"
          fi