package cmd

import (
	"fmt"
	"log"
	"os"
	"regexp"
	"text/template"

	"github.com/runconduit/conduit/controller"
	uuid "github.com/satori/go.uuid"
	"github.com/spf13/cobra"
)

var conduitTemplate = `### Namespace ###
kind: Namespace
apiVersion: v1
metadata:
  name: {{.Namespace}}

### Service Account Controller ###
---
kind: ServiceAccount
apiVersion: v1
metadata:
  name: conduit-controller
  namespace: conduit

### RBAC ###
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: conduit-controller
rules:
- apiGroups: ["extensions"]
  resources: ["deployments", "replicasets"]
  verbs: ["list", "get", "watch"]
- apiGroups: [""]
  resources: ["pods", "endpoints", "services"]
  verbs: ["list", "get", "watch"]

---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: conduit-controller
  namespace: conduit
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: conduit-controller
subjects:
- kind: ServiceAccount
  name: conduit-controller
  namespace: conduit

### Service Account Prometheus ###
---
kind: ServiceAccount
apiVersion: v1
metadata:
  name: conduit-prometheus
  namespace: conduit

### RBAC ###
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: conduit-prometheus
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["list", "watch"]

---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: conduit-prometheus
  namespace: conduit
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: conduit-prometheus
subjects:
- kind: ServiceAccount
  name: conduit-prometheus
  namespace: conduit

### Controller ###
---
kind: Service
apiVersion: v1
metadata:
  name: api
  namespace: {{.Namespace}}
  labels:
    app: controller
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  type: ClusterIP
  selector:
    app: controller
  ports:
  - name: http
    port: 8085
    targetPort: 8085

---
kind: Service
apiVersion: v1
metadata:
  name: proxy-api
  namespace: {{.Namespace}}
  labels:
    app: controller
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  type: ClusterIP
  selector:
    app: controller
  ports:
  - name: grpc
    port: 8086
    targetPort: 8086

---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: controller
  namespace: {{.Namespace}}
  labels:
    app: controller
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  replicas: {{.ControllerReplicas}}
  template:
    metadata:
      labels:
        app: controller
        conduit.io/plane: control
      annotations:
        conduit.io/created-by: "{{.CliVersion}}"
    spec:
      serviceAccount: conduit-controller
      containers:
      - name: public-api
        ports:
        - name: http
          containerPort: 8085
        - name: admin-http
          containerPort: 9995
        image: {{.ControllerImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "public-api"
        - "-addr=:8085"
        - "-metrics-addr=:9995"
        - "-telemetry-addr=127.0.0.1:8087"
        - "-tap-addr=127.0.0.1:8088"
      - name: destination
        ports:
        - name: grpc
          containerPort: 8089
        - name: admin-http
          containerPort: 9999
        image: {{.ControllerImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "destination"
        - "-addr=:8089"
        - "-metrics-addr=:9999"
      - name: proxy-api
        ports:
        - name: grpc
          containerPort: 8086
        - name: admin-http
          containerPort: 9996
        image: {{.ControllerImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "proxy-api"
        - "-addr=:8086"
        - "-metrics-addr=:9996"
        - "-destination-addr=:8089"
        - "-telemetry-addr=:8087"
      - name: tap
        ports:
        - name: grpc
          containerPort: 8088
        - name: admin-http
          containerPort: 9998
        image: {{.ControllerImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "tap"
        - "-addr=:8088"
        - "-metrics-addr=:9998"
      - name: telemetry
        ports:
        - name: grpc
          containerPort: 8087
        - name: admin-http
          containerPort: 9997
        image: {{.ControllerImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "telemetry"
        - "-addr=:8087"
        - "-metrics-addr=:9997"
        - "-ignore-namespaces=kube-system"
        - "-prometheus-url=http://prometheus:9090"

### Web ###
---
kind: Service
apiVersion: v1
metadata:
  name: web
  namespace: {{.Namespace}}
  labels:
    app: web
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  type: ClusterIP
  selector:
    app: web
  ports:
  - name: http
    port: 8084
    targetPort: 8084
  - name: admin-http
    port: 9994
    targetPort: 9994

---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: web
  namespace: {{.Namespace}}
  labels:
    app: web
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  replicas: {{.WebReplicas}}
  template:
    metadata:
      labels:
        app: web
        conduit.io/plane: control
      annotations:
        conduit.io/created-by: "{{.CliVersion}}"
    spec:
      containers:
      - name: web
        ports:
        - name: http
          containerPort: 8084
        - name: admin-http
          containerPort: 9994
        image: {{.WebImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "-addr=:8084"
        - "-metrics-addr=:9994"
        - "-api-addr=api:8085"
        - "-static-dir=/dist"
        - "-template-dir=/templates"
        - "-uuid={{.UUID}}"

### Prometheus ###
---
kind: Service
apiVersion: v1
metadata:
  name: prometheus
  namespace: {{.Namespace}}
  labels:
    app: prometheus
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  type: ClusterIP
  selector:
    app: prometheus
  ports:
  - name: http
    port: 9090
    targetPort: 9090

---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: prometheus
  namespace: {{.Namespace}}
  labels:
    app: prometheus
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
spec:
  replicas: {{.PrometheusReplicas}}
  template:
    metadata:
      labels:
        app: prometheus
        conduit.io/plane: control
      annotations:
        conduit.io/created-by: "{{.CliVersion}}"
    spec:
      serviceAccount: conduit-prometheus
      volumes:
      - name: prometheus-config
        configMap:
          name: prometheus-config
      containers:
      - name: prometheus
        ports:
        - name: http
          containerPort: 9090
        volumeMounts:
        - name: prometheus-config
          mountPath: /etc/prometheus
          readOnly: true
        image: {{.PrometheusImage}}
        imagePullPolicy: {{.ImagePullPolicy}}
        args:
        - "-storage.local.retention=6h"
        - "-storage.local.memory-chunks=500000"
        - "-config.file=/etc/prometheus/prometheus.yml"

      # TODO remove/replace?
      - name: kubectl
        image: buoyantio/kubectl:v1.6.2
        args: ["proxy", "-p", "8001"]

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: prometheus-config
  namespace: {{.Namespace}}
  labels:
    app: prometheus
    conduit.io/plane: control
  annotations:
    conduit.io/created-by: "{{.CliVersion}}"
data:
  prometheus.yml: |-
    global:
      scrape_interval: 10s
      evaluation_interval: 10s

    scrape_configs:
    - job_name: 'prometheus'
      static_configs:
      - targets: ['localhost:9090']

    - job_name: 'controller'
      kubernetes_sd_configs:
      - role: pod
        namespaces:
          names: ['{{.Namespace}}']
      relabel_configs:
      - source_labels: [__meta_kubernetes_pod_container_port_name]
        action: keep
        regex: ^admin-http$
      - source_labels: [__meta_kubernetes_pod_container_name]
        action: replace
        target_label: job
`

type installConfig struct {
	Namespace          string
	ControllerImage    string
	WebImage           string
	PrometheusImage    string
	ControllerReplicas uint
	WebReplicas        uint
	PrometheusReplicas uint
	ImagePullPolicy    string
	UUID               string
	CliVersion         string
}

var (
	version            string
	dockerRegistry     string
	controllerReplicas uint
	webReplicas        uint
	prometheusReplicas uint
	imagePullPolicy    string
)

var installCmd = &cobra.Command{
	Use:   "install [flags]",
	Short: "Output Kubernetes configs to install Conduit",
	Long:  "Output Kubernetes configs to install Conduit.",
	RunE: func(cmd *cobra.Command, args []string) error {
		if err := validate(); err != nil {
			log.Fatal(err.Error())
		}
		template, err := template.New("conduit").Parse(conduitTemplate)
		if err != nil {
			return err
		}
		template.Execute(os.Stdout, installConfig{
			Namespace:          controlPlaneNamespace,
			ControllerImage:    fmt.Sprintf("%s/controller:%s", dockerRegistry, version),
			WebImage:           fmt.Sprintf("%s/web:%s", dockerRegistry, version),
			PrometheusImage:    "prom/prometheus:v1.8.1",
			ControllerReplicas: controllerReplicas,
			WebReplicas:        webReplicas,
			PrometheusReplicas: prometheusReplicas,
			ImagePullPolicy:    imagePullPolicy,
			UUID:               uuid.NewV4().String(),
			CliVersion:         fmt.Sprintf("conduit/cli %s", controller.Version),
		})
		return nil
	},
}

var alphaNumDash = regexp.MustCompile("^[a-zA-Z0-9-]+$")
var alphaNumDashDot = regexp.MustCompile("^[\\.a-zA-Z0-9-]+$")
var alphaNumDashDotSlash = regexp.MustCompile("^[\\./a-zA-Z0-9-]+$")

func validate() error {
	// These regexs are not as strict as they could be, but are a quick and dirty
	// sanity check against illegal characters.
	if !alphaNumDash.MatchString(controlPlaneNamespace) {
		return fmt.Errorf("%s is not a valid namespace", controlPlaneNamespace)
	}
	if !alphaNumDashDot.MatchString(version) {
		return fmt.Errorf("%s is not a valid version", version)
	}
	if !alphaNumDashDotSlash.MatchString(dockerRegistry) {
		return fmt.Errorf("%s is not a valid Docker registry", dockerRegistry)
	}
	if imagePullPolicy != "Always" && imagePullPolicy != "IfNotPresent" && imagePullPolicy != "Never" {
		return fmt.Errorf("imagePullPolicy must be one of Always, IfNotPresent, or Never")
	}
	return nil
}

func init() {
	RootCmd.AddCommand(installCmd)
	installCmd.PersistentFlags().StringVarP(&version, "version", "v", controller.Version, "Conduit version to install")
	installCmd.PersistentFlags().StringVarP(&dockerRegistry, "registry", "r", "gcr.io/runconduit", "Docker registry to pull images from")
	installCmd.PersistentFlags().UintVar(&controllerReplicas, "controller-replicas", 1, "replicas of the controller to deploy")
	installCmd.PersistentFlags().UintVar(&webReplicas, "web-replicas", 1, "replicas of the web server to deploy")
	installCmd.PersistentFlags().UintVar(&prometheusReplicas, "prometheus-replicas", 1, "replicas of prometheus to deploy")
	installCmd.PersistentFlags().StringVar(&imagePullPolicy, "image-pull-policy", "IfNotPresent", "Docker image pull policy")
}