name: Validate Helm Charts
on:
  pull_request:

jobs:
  detect-changed-charts:
    name: Detect changed charts
    runs-on: ubuntu-latest
    outputs:
      charts: ${{ steps.detect.outputs.charts }}
      any: ${{ steps.detect.outputs.any }}
    steps:
      - name: "Checkout Repository"
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: "Detect changed charts"
        id: detect
        run: |
          CHARTS="[]"
          CHANGED_DIRS=$(git diff --name-only "origin/${{ github.base_ref }}...HEAD" | cut -d/ -f1 | sort -u)
          for DIR in $CHANGED_DIRS; do
            if [ -f "$DIR/Chart.yaml" ]; then
              CHARTS=$(echo "$CHARTS" | jq -c --arg dir "$DIR" '. + [$dir]')
            fi
          done
          echo "charts=$CHARTS" >> "$GITHUB_OUTPUT"
          if [ "$CHARTS" = "[]" ]; then
            echo "any=false" >> "$GITHUB_OUTPUT"
            echo "No chart directories changed - nothing to build."
          else
            echo "any=true" >> "$GITHUB_OUTPUT"
            echo "Changed charts: $CHARTS"
          fi

  build-chart:
    name: "Build ${{ matrix.chart }}"
    needs: detect-changed-charts
    if: needs.detect-changed-charts.outputs.any == 'true'
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        chart: ${{ fromJSON(needs.detect-changed-charts.outputs.charts) }}
    steps:
      - name: "Checkout Repository"
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: "Install Helm"
        uses: azure/setup-helm@v4
      - name: "Lint Helm Chart"
        run: helm lint --strict "${{ matrix.chart }}"
      - name: "Package Helm Chart"
        run: helm package "${{ matrix.chart }}"
      - name: "Check Chart Version was bumped"
        # template-chart is a scaffold and never published, its version is meaningless
        if: matrix.chart != 'template-chart'
        run: |
          BASE_VERSION=$(git show "origin/${{ github.base_ref }}:${{ matrix.chart }}/Chart.yaml" 2>/dev/null | grep '^version:' | awk '{print $2}' || true)
          NEW_VERSION=$(grep '^version:' "${{ matrix.chart }}/Chart.yaml" | awk '{print $2}')
          if [ -z "$BASE_VERSION" ]; then
            echo "New chart (does not exist on ${{ github.base_ref }}), version: $NEW_VERSION"
          elif [ "$BASE_VERSION" = "$NEW_VERSION" ]; then
            echo "::error file=${{ matrix.chart }}/Chart.yaml::Chart '${{ matrix.chart }}' was modified but its version was not bumped (still $BASE_VERSION). Bump 'version:' in Chart.yaml, otherwise the publish on main will collide with the already published version."
            exit 1
          else
            echo "Version bump OK: $BASE_VERSION -> $NEW_VERSION"
          fi