docker-publish.yml

name: Docker

on:
  push:
    branches: ["dev", "main"]
    tags: ["v*.*.*"]
  pull_request:
    branches: ["dev", "main"]
  workflow_dispatch:

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

jobs:
  detect-changes:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.set-matrix.outputs.matrix }}
      has-changes: ${{ steps.set-matrix.outputs.has-changes }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          submodules: recursive

      - name: Detect changed paths
        id: set-matrix
        run: |
          # Initialize empty matrix
          MATRIX_INCLUDE="[]"
          HAS_CHANGES=false

          # Function to add to matrix
          add_to_matrix() {
            local context=$1
            local suffix=$2
            local dockerfile=$3
            local component=$4
            # Use jq to robustly add the object to the array
            MATRIX_INCLUDE=$(echo "$MATRIX_INCLUDE" | jq -c ". + [{\"context\":\"$context\",\"image-suffix\":\"$suffix\",\"dockerfile\":\"$dockerfile\",\"component\":\"$component\"}]")
            HAS_CHANGES=true
          }

          # Check if we should build everything (tags, PRs, or workflow change)
          # Check if we should build everything
          FORCE_BUILD=false
          BASE_REF="HEAD~1"

          # Intelligent Tag Handling
          if [[ "${{ github.ref }}" == refs/tags/* ]]; then
            # Try to find the previous tag (abbrev=0 to get clean tag name)
            PREV_TAG=$(git describe --tags --abbrev=0 HEAD^ 2>/dev/null || echo "")
            
            if [ -z "$PREV_TAG" ]; then
              # No previous tag found (first release), force full build
              echo "No previous tag found. Forcing full build."
              FORCE_BUILD=true
            else
              # Diff against the previous tag
              BASE_REF="$PREV_TAG"
              echo "Comparing this tag (${{ github.ref_name }}) against previous tag: $PREV_TAG"
            fi
          elif [[ "${{ github.event_name }}" == "pull_request" ]]; then
            # For PRs, we currently force build to ensure stability, 
            # though this could be optimized to compare against target branch in future.
            FORCE_BUILD=true
          fi

          # Check for workflow changes (always rebuild if pipeline changes)
          # We use BASE_REF here to catch workflow changes in the range
          if git diff --name-only "$BASE_REF" HEAD | grep -q "\.github/workflows/docker-publish\.yml"; then
            echo "Workflow file changed. Forcing full build."
            FORCE_BUILD=true
          fi

          if [ "$FORCE_BUILD" = true ]; then
            add_to_matrix "." "" "Dockerfile" "core"
            add_to_matrix "./rf-engine" "-rf-engine" "./rf-engine/Dockerfile" "rf-engine"
            add_to_matrix "opentopodata" "-opentopodata" "opentopodata/docker/Dockerfile" "opentopodata"
          else
            echo "Checking for changes relative to: $BASE_REF"
            
            # Core/root image changes
            if git diff --name-only "$BASE_REF" HEAD | grep -E '(Dockerfile|\.go$|\.py$|requirements|package\.json|\.ts$|\.js$)' | grep -qv "rf-engine\|opentopodata"; then
              add_to_matrix "." "" "Dockerfile" "core"
            fi

            # rf-engine changes
            if git diff --name-only "$BASE_REF" HEAD | grep -q "^rf-engine/"; then
              add_to_matrix "./rf-engine" "-rf-engine" "./rf-engine/Dockerfile" "rf-engine"
            fi

            # opentopodata changes
            if git diff --name-only "$BASE_REF" HEAD | grep -E -q "^opentopodata(/|$)"; then
              add_to_matrix "opentopodata" "-opentopodata" "opentopodata/docker/Dockerfile" "opentopodata"
            fi
          fi

          # finalize matrix JSON
          MATRIX=$(echo "{}" | jq -c ".include = $MATRIX_INCLUDE")

          echo "Detected changes: $HAS_CHANGES"
          echo "Matrix: $MATRIX"

          echo "matrix=$MATRIX" >> $GITHUB_OUTPUT
          echo "has-changes=$HAS_CHANGES" >> $GITHUB_OUTPUT

  build:
    needs: detect-changes
    if: ${{ needs.detect-changes.outputs.has-changes == 'true' }}
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    strategy:
      fail-fast: false
      matrix: ${{ fromJson(needs.detect-changes.outputs.matrix) }}

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

      - name: Verify Submodules
        run: |
          git submodule update --init --recursive
          ls -R opentopodata

      - name: Lowercase Image Name
        run: |
          echo "IMAGE_NAME=${GITHUB_REPOSITORY,,}" >> ${GITHUB_ENV}

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

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

      - name: Log into registry ${{ env.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 Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}${{ matrix.image-suffix }}
          tags: |
            type=ref,event=branch
            type=ref,event=tag
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: ${{ matrix.context }}
          file: ${{ matrix.dockerfile }}
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: |
            type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}${{ matrix.image-suffix }}:buildcache
            type=gha
          cache-to: type=gha,mode=max