/*
 * Copyright © 2020 Atomist, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import * as gcp from "@pulumi/gcp";
import * as k8s from "@pulumi/kubernetes";
import * as pulumi from "@pulumi/pulumi";

/** Arguments to [[clusterProvider]]. */
export interface ClusterProviderArgs {
	/** GKE cluster to create provider for. */
	cluster: gcp.container.Cluster;
	/** Optional name of resource provider to create. */
	name?: string;
}

/**
 * Create a Pulumi Kubernetes provider from a GKE cluster.
 */
export function clusterProvider(opts: ClusterProviderArgs): k8s.Provider {
	const providerName = opts.name || "k8s-provider";
	const clusterIdentifier = opts.cluster.name;
	const kubeconfig = pulumi
		.all([
			opts.cluster.name,
			opts.cluster.controlPlaneEndpointsConfig.dnsEndpointConfig.endpoint,
			opts.cluster.location,
			opts.cluster.project,
		])
		.apply(([name, endpoint, location, projectId]) => {
			const context = `${projectId}_${location}_${name}`;
			return `apiVersion: v1
clusters:
- cluster:
    server: https://${endpoint}
  name: ${context}
contexts:
- context:
    cluster: ${context}
    user: ${context}
  name: ${context}
current-context: ${context}
kind: Config
preferences: {}
users:
- name: ${context}
  user:
    exec:
      apiVersion: client.authentication.k8s.io/v1beta1
      command: gke-gcloud-auth-plugin
      installHint: Install gke-gcloud-auth-plugin for use with kubectl by following
        https://cloud.google.com/kubernetes-engine/docs/how-to/cluster-access-for-kubectl#install_plugin
      provideClusterInfo: true
`;
		});
	return new k8s.Provider(providerName, { clusterIdentifier, kubeconfig });
}