name: Helm Diff Deployment
description: Diff a Helm chart for a deployment in a Kubernetes cluster
inputs:
  DEPLOYMENT_NAME:
    description: "The Helm release name"
    required: true
  DEPLOYMENT_NAMESPACE:
    description: "The Kubernetes namespace (defaults to DEPLOYMENT_NAME)"
    default: ""
  REGISTRY:
    description: "OCI registry hostname for helm dependency login"
    required: true
  REGISTRY_USERNAME:
    description: "Username for OCI registry login"
    required: true
  REGISTRY_TOKEN:
    description: "Token for OCI registry login"
    required: true
  CHART_PATH:
    description: "Path to the Helm chart"
    default: "./helm"
  VALUES_FILE:
    description: "The values file to use"
    default: "./helm/values.yaml"
  IMAGE_PATH:
    description: "The registry path to the image (optional)"
    default: ""
  IMAGE_TAG:
    description: "The image tag to deploy (optional)"
    default: ""
  TAG_KEY:
    description: "Helm --set key for the image tag (e.g. deploy.api.tag)"
    default: ""

runs:
  using: composite
  steps:
    - name: Helm OCI Login
      shell: sh
      env:
        REGISTRY: ${{ inputs.REGISTRY }}
        REGISTRY_USERNAME: ${{ inputs.REGISTRY_USERNAME }}
        REGISTRY_TOKEN: ${{ inputs.REGISTRY_TOKEN }}
      run: |
        echo "$REGISTRY_TOKEN" | helm registry login "$REGISTRY" \
          --username "$REGISTRY_USERNAME" \
          --password-stdin

    - name: Install Helm Diff
      shell: sh
      run: |
        helm plugin list | grep -q diff || helm plugin install https://github.com/databus23/helm-diff

    - name: Helm Diff
      shell: sh
      env:
        DEPLOYMENT_NAME: ${{ inputs.DEPLOYMENT_NAME }}
        DEPLOYMENT_NAMESPACE: ${{ inputs.DEPLOYMENT_NAMESPACE }}
        CHART_PATH: ${{ inputs.CHART_PATH }}
        VALUES_FILE: ${{ inputs.VALUES_FILE }}
        IMAGE_PATH: ${{ inputs.IMAGE_PATH }}
        IMAGE_TAG: ${{ inputs.IMAGE_TAG }}
        TAG_KEY: ${{ inputs.TAG_KEY }}
      run: |
        NAMESPACE="$DEPLOYMENT_NAMESPACE"
        if [ -z "$NAMESPACE" ]; then NAMESPACE="$DEPLOYMENT_NAME"; fi
        SET_FLAGS=""
        if [ -n "$TAG_KEY" ] && [ -n "$IMAGE_TAG" ]; then
          SET_FLAGS="$SET_FLAGS --set $TAG_KEY=$IMAGE_TAG"
        fi
        if [ -n "$IMAGE_PATH" ]; then
          SET_FLAGS="$SET_FLAGS --set image.repository=$IMAGE_PATH"
        fi
        helm dependency update "$CHART_PATH"
        helm diff upgrade "$DEPLOYMENT_NAME" "$CHART_PATH" -n "$NAMESPACE" --values "$VALUES_FILE" $SET_FLAGS --context 5