// Copyright © 2017 The virtual-kubelet authors
//
// 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 cmd

import (
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"

	homedir "github.com/mitchellh/go-homedir"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
	"github.com/virtual-kubelet/virtual-kubelet/providers"
	vkubelet "github.com/virtual-kubelet/virtual-kubelet/vkubelet"
	corev1 "k8s.io/api/core/v1"
)

var kubeletConfig string
var kubeConfig string
var kubeNamespace string
var nodeName string
var operatingSystem string
var provider string
var providerConfig string
var taint string

// RootCmd represents the base command when called without any subcommands
var RootCmd = &cobra.Command{
	Use:   "virtual-kubelet",
	Short: "virtual-kubelet provides a virtual kubelet interface for your kubernetes cluster.",
	Long: `virtual-kubelet implements the Kubelet interface with a pluggable 
backend implementation allowing users to create kubernetes nodes without running the kubelet.
This allows users to schedule kubernetes workloads on nodes that aren't running Kubernetes.`,
	Run: func(cmd *cobra.Command, args []string) {
		fmt.Println(kubeConfig)
		f, err := vkubelet.New(nodeName, operatingSystem, kubeNamespace, kubeConfig, taint, provider, providerConfig)
		if err != nil {
			log.Fatal(err)
		}
		f.Run()
	},
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	if err := RootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	// read default node name from environment variable.
	// it can be overwritten by cli flags if specified.
	if os.Getenv("DEFAULT_NODE_NAME") != "" {
		nodeName = os.Getenv("DEFAULT_NODE_NAME")
	}
	// Here you will define your flags and configuration settings.
	// Cobra supports persistent flags, which, if defined here,
	// will be global for your application.
	//RootCmd.PersistentFlags().StringVar(&kubeletConfig, "config", "", "config file (default is $HOME/.virtual-kubelet.yaml)")
	RootCmd.PersistentFlags().StringVar(&kubeConfig, "kubeconfig", "", "config file (default is $HOME/.kube/config)")
	RootCmd.PersistentFlags().StringVar(&kubeNamespace, "namespace", "", "kubernetes namespace (default is 'all')")
	RootCmd.PersistentFlags().StringVar(&nodeName, "nodename", "virtual-kubelet", "kubernetes node name")
	RootCmd.PersistentFlags().StringVar(&operatingSystem, "os", "Linux", "Operating System (Linux/Windows)")
	RootCmd.PersistentFlags().StringVar(&provider, "provider", "", "cloud provider")
	RootCmd.PersistentFlags().StringVar(&taint, "taint", "", "apply taint to node, making scheduling explicit")
	RootCmd.PersistentFlags().StringVar(&providerConfig, "provider-config", "", "cloud provider configuration file")

	// Cobra also supports local flags, which will only run
	// when this action is called directly.
	// RootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
}

// initConfig reads in config file and ENV variables if set.
func initConfig() {
	if provider == "" {
		fmt.Println("You must supply a cloud provider option: use --provider")
		os.Exit(1)
	}

	// Find home directory.
	home, err := homedir.Dir()
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	if kubeletConfig != "" {
		// Use config file from the flag.
		viper.SetConfigFile(kubeletConfig)
	} else {
		// Search config in home directory with name ".virtual-kubelet" (without extension).
		viper.AddConfigPath(home)
		viper.SetConfigName(".virtual-kubelet")
	}

	viper.AutomaticEnv() // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Println("Using config file:", viper.ConfigFileUsed())
	}

	if kubeConfig == "" {
		kubeConfig = filepath.Join(home, ".kube", "config")

	}

	if kubeNamespace == "" {
		kubeNamespace = corev1.NamespaceAll
	}

	// Validate operating system.
	ok, _ := providers.ValidOperatingSystems[operatingSystem]
	if !ok {
		fmt.Printf("Operating system '%s' not supported. Valid options are %s\n", operatingSystem, strings.Join(providers.ValidOperatingSystems.Names(), " | "))
		os.Exit(1)
	}
}