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-chart-changed: ${{ steps.detect.outputs.any-chart-changed }}
      scan-charts: ${{ steps.detect.outputs.scan-charts }}
      any-scan: ${{ steps.detect.outputs.any-scan }}
    steps:
      - name: "Checkout Repository"
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: "Detect changed charts"
        id: detect
        run: |
          CHANGED_FILES=$(git diff --name-only "origin/${{ github.base_ref }}...HEAD")
          CHARTS="[]"
          CHANGED_DIRS=$(echo "$CHANGED_FILES" | 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 [ "$CHARTS" = "[]" ]; then
            echo "any-chart-changed=false" >> "$GITHUB_OUTPUT"
            echo "No chart directories changed - nothing to build."
          else
            echo "any-chart-changed=true" >> "$GITHUB_OUTPUT"
            echo "Changed charts: $CHARTS"
          fi

          # The Trivy scan normally follows the changed charts. But a PR that
          # changes the scanner itself touches no chart at all, and would leave
          # the change untested. In that case scan a fixed sample instead, one
          # chart per interesting case: a documented deviation (samba), a fully
          # hardened one (cyberchef), and one with two workloads
          # (matrix-synapse).
          SCAN_CHARTS="$CHARTS"
          if [ "$CHARTS" = "[]" ] && echo "$CHANGED_FILES" | grep -qE '^(ci/(run-trivy-config\.sh|trivy/)|\.github/workflows/validate-charts\.yml)'; then
            SCAN_CHARTS='["samba","cyberchef","matrix-synapse"]'
            echo "Scanner changed without a chart change - scanning the sample: $SCAN_CHARTS"
          fi
          echo "scan-charts=$SCAN_CHARTS" >> "$GITHUB_OUTPUT"
          if [ "$SCAN_CHARTS" = "[]" ]; then
            echo "any-scan=false" >> "$GITHUB_OUTPUT"
          else
            echo "any-scan=true" >> "$GITHUB_OUTPUT"
          fi

  build-chart:
    name: "Build ${{ matrix.chart }}"
    needs: detect-changed-charts
    if: needs.detect-changed-charts.outputs.any-chart-changed == '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

  trivy-config:
    name: "Trivy config ${{ matrix.chart }}"
    needs: detect-changed-charts
    if: needs.detect-changed-charts.outputs.any-scan == 'true'
    runs-on: ubuntu-latest
    # Reporting only (issue #84): the scan renders each changed chart and lists
    # what `trivy config` finds, but it never fails the job - see
    # TRIVY_CONFIG_MODE below. Deliberately not a gate yet: the repo has several
    # documented deviations, and a check that goes red on those every time is one
    # people learn to scroll past. Depends only on detect-changed-charts, so it
    # runs beside build-chart and adds no wall-clock time to the pipeline.
    strategy:
      fail-fast: false
      matrix:
        chart: ${{ fromJSON(needs.detect-changed-charts.outputs.scan-charts) }}
    env:
      TRIVY_VERSION: v0.74.0
      # "report" always exits 0. Switch to "gate" to make a finding that no
      # documented exception covers fail the job - the intended step once the
      # seccomp gap (#84) is closed.
      TRIVY_CONFIG_MODE: report
    steps:
      - name: "Checkout Repository"
        uses: actions/checkout@v4
      - name: "Install Helm"
        uses: azure/setup-helm@v4
      - name: "Install Trivy"
        uses: aquasecurity/setup-trivy@v0.3.1
        with:
          version: ${{ env.TRIVY_VERSION }}
          cache: true
      # Findings land in the job summary, not only in the log: exceptions with
      # their reasons come from ci/trivy/trivyignore.yaml, the trusted-registry
      # list from ci/trivy/data/ksv0125.yaml.
      - name: "Scan rendered manifests"
        run: ci/run-trivy-config.sh "${{ matrix.chart }}"

  install-test:
    name: "Install-test ${{ matrix.chart }}"
    needs: [detect-changed-charts, build-chart]
    if: needs.detect-changed-charts.outputs.any-chart-changed == 'true'
    runs-on: ubuntu-latest
    # Stabilization phase (issue #22): the job reports failures but does not
    # block the PR. Promote to a required check (drop continue-on-error) once
    # it has proven stable across several chart PRs.
    continue-on-error: true
    timeout-minutes: 30
    strategy:
      fail-fast: false
      matrix:
        chart: ${{ fromJSON(needs.detect-changed-charts.outputs.charts) }}
    env:
      K3D_VERSION: v5.9.0
      K3S_IMAGE: docker.io/rancher/k3s:v1.35.5-k3s1
    steps:
      - name: "Checkout Repository"
        uses: actions/checkout@v4
      - name: "Install Helm"
        uses: azure/setup-helm@v4
      - name: "Install k3d"
        run: curl -sSfL https://raw.githubusercontent.com/k3d-io/k3d/main/install.sh | TAG="$K3D_VERSION" bash
      - name: "Create k3d cluster"
        run: k3d cluster create install-test --image "$K3S_IMAGE" --wait --timeout 180s
      # Excluded charts (see ci/excluded-charts.txt) are skipped inside the
      # script with their documented reason.
      - name: "Install chart and wait for readiness"
        run: ci/run-install-test.sh "${{ matrix.chart }}"
      - name: "Delete k3d cluster"
        if: always()
        run: k3d cluster delete install-test || true