/*
Copyright 2016 The Kubernetes Authors All rights reserved.

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.
*/

package client

import (
	"bytes"
	"fmt"
	"text/template"

	"github.com/Masterminds/sprig"

	"k8s.io/helm/pkg/kube"
)

// Install uses kubernetes client to install tiller
//
// Returns the string output received from the operation, and an error if the
// command failed.
//
// If verbose is true, this will print the manifest to stdout.
func Install(namespace, image string, verbose bool) error {
	kc := kube.New(nil)

	if namespace == "" {
		ns, _, err := kc.DefaultNamespace()
		if err != nil {
			return err
		}
		namespace = ns
	}

	var b bytes.Buffer

	// Add main install YAML
	istpl := template.New("install").Funcs(sprig.TxtFuncMap())

	cfg := struct {
		Namespace, Image string
	}{namespace, image}

	if err := template.Must(istpl.Parse(InstallYAML)).Execute(&b, cfg); err != nil {
		return err
	}

	if verbose {
		fmt.Println(b.String())
	}

	return kc.Create(namespace, &b)
}

// InstallYAML is the installation YAML for DM.
const InstallYAML = `
---
apiVersion: v1
kind: ReplicationController
metadata:
  labels:
    app: helm
    name: tiller
  name: tiller-rc
  namespace: {{ .Namespace }}
spec:
  replicas: 1
  selector:
    app: helm
    name: tiller
  template:
    metadata:
      labels:
        app: helm
        name: tiller
    spec:
      containers:
      - env:
          - name: DEFAULT_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        image: {{default "gcr.io/kubernetes-helm/tiller:canary" .Image}}
        name: tiller
        ports:
        - containerPort: 44134
          name: tiller
        imagePullPolicy: Always
        livenessProbe:
          httpGet:
            path: /liveness
            port: 44135
          initialDelaySeconds: 1
          timeoutSeconds: 1
        readinessProbe:
          httpGet:
            path: /readiness
            port: 44135
          initialDelaySeconds: 1
          timeoutSeconds: 1
`