name: Lint Opik Helm Chart
run-name: "Lint Opik Helm Chart ${{ github.ref_name }} by @${{ github.actor }}"

on:
  workflow_dispatch:
  pull_request:
    paths: 
      - "deployment/helm_chart/opik/**"
  push:
    branches: 
      - 'main'
    paths: 
      - "deployment/helm_chart/opik/**"


concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

# This workflow only reads the repo (lint + render); no write access needed.
permissions:
  contents: read

jobs:
  
  lint-helm-chart:
    runs-on: ubuntu-latest
    timeout-minutes: 5

    strategy:
      fail-fast: false
      matrix:
        # Prove dual compatibility: the chart must keep working on Helm 3.x
        # while also rendering cleanly under Helm 4.x (DND-537).
        helm-version:
          - v3.21.0
          - v4.2.0

    name: lint-helm-chart (Helm ${{ matrix.helm-version }})

    steps:
        - name: Checkout
          uses: actions/checkout@v6

        - name: Install Helm ${{ matrix.helm-version }}
          uses: azure/setup-helm@v4.3.1
          with:
            version: ${{ matrix.helm-version }}

        - name: Run lint on Helm chart
          run: |
              set -e
              cd deployment/helm_chart/opik
              helm repo add mysql https://comet-ml.github.io/comet-mysql-helm/
              helm repo add bitnami https://charts.bitnami.com/bitnami
              helm repo add clickhouse-operator https://docs.altinity.com/clickhouse-operator
              helm dependency build
              helm lint --values values.yaml .
              cd -

  # Assert the rendered content of specific resources (e.g. the `opik.probe`
  # helper) via helm-unittest. Tests live in deployment/helm_chart/opik/tests/.
  unittest-helm-chart:
    runs-on: ubuntu-latest
    timeout-minutes: 5

    steps:
        - name: Checkout
          uses: actions/checkout@v6

        - name: Install Helm
          uses: azure/setup-helm@v4.3.1
          with:
            version: v3.21.0

        - name: Install helm-unittest plugin
          run: helm plugin install https://github.com/helm-unittest/helm-unittest

        - name: Run helm unittest
          run: |
              set -e
              cd deployment/helm_chart/opik
              helm repo add mysql https://comet-ml.github.io/comet-mysql-helm/
              helm repo add bitnami https://charts.bitnami.com/bitnami
              helm repo add clickhouse-operator https://docs.altinity.com/clickhouse-operator
              helm dependency build
              helm unittest .
              cd -

  # Prove the chart renders equivalently under Helm 3.x and Helm 4.x so we can ship
  # Helm 4 support without changing behavior for Helm 3 users (DND-537). Each version
  # resolves its own dependencies (`helm dependency build`) and renders from scratch.
  # Helm 4 only differs from Helm 3 in trailing whitespace it emits between manifests,
  # which YAML ignores and does not change any rendered Kubernetes object — so we
  # compare after stripping trailing whitespace and blank lines.
  render-equality:
    runs-on: ubuntu-latest
    timeout-minutes: 10

    steps:
        - name: Checkout
          uses: actions/checkout@v6

        - name: Render with Helm 3.x
          uses: azure/setup-helm@v4.3.1
          with:
            version: v3.21.0

        - name: helm template (Helm 3.x)
          run: |
              set -e
              cd deployment/helm_chart/opik
              rm -rf charts Chart.lock
              helm repo add mysql https://comet-ml.github.io/comet-mysql-helm/
              helm repo add bitnami https://charts.bitnami.com/bitnami
              helm repo add clickhouse-operator https://docs.altinity.com/clickhouse-operator
              helm dependency build
              helm template opik . --values values.yaml > "${RUNNER_TEMP}/render-helm3.yaml"
              cd -

        - name: Render with Helm 4.x
          uses: azure/setup-helm@v4.3.1
          with:
            version: v4.2.0

        - name: helm template (Helm 4.x)
          run: |
              set -e
              cd deployment/helm_chart/opik
              # Wipe Helm 3's resolved deps so Helm 4 runs its own dependency resolution.
              rm -rf charts Chart.lock
              helm repo add mysql https://comet-ml.github.io/comet-mysql-helm/
              helm repo add bitnami https://charts.bitnami.com/bitnami
              helm repo add clickhouse-operator https://docs.altinity.com/clickhouse-operator
              helm dependency build
              helm template opik . --values values.yaml > "${RUNNER_TEMP}/render-helm4.yaml"
              cd -

        - name: Diff rendered output (semantically; must be identical)
          run: |
              set -e
              # Compare by parsing every rendered YAML document and re-serializing it
              # canonically (sorted keys), instead of a line-based diff. This ignores the
              # ONLY thing Helm 4 changes vs Helm 3 — cosmetic inter-document spacing and
              # trailing whitespace — while preserving real content, including blank lines
              # *inside* block scalars (e.g. embedded config in ConfigMaps). A line-based
              # blank-line strip would hide those; a YAML round-trip does not.
              canonicalize() {
                python3 - "$1" <<'PY'
              import sys, yaml
              docs = [d for d in yaml.safe_load_all(open(sys.argv[1])) if d is not None]
              sys.stdout.write(yaml.safe_dump_all(docs, sort_keys=True, default_flow_style=False))
              PY
              }
              canonicalize "${RUNNER_TEMP}/render-helm3.yaml" > "${RUNNER_TEMP}/render-helm3.norm.yaml"
              canonicalize "${RUNNER_TEMP}/render-helm4.yaml" > "${RUNNER_TEMP}/render-helm4.norm.yaml"
              if ! diff -u "${RUNNER_TEMP}/render-helm3.norm.yaml" "${RUNNER_TEMP}/render-helm4.norm.yaml"; then
                echo "::error::Rendered manifests differ between Helm 3.x and Helm 4.x. The chart must render equivalently on both."
                exit 1
              fi
              echo "Helm 3.x and Helm 4.x produce equivalent rendered manifests."