package cmd

import (
	"fmt"

	"github.com/coredns/deployment/kubernetes/migration"

	"github.com/spf13/cobra"
)

// NewDefaultCmd represents the default command
func NewDefaultCmd() *cobra.Command {
	defaultCmd := &cobra.Command{
		Use:   "default",
		Short: "default returns true if the Corefile is the default for a that version of Kubernetes. If the Kubernetes version is omitted, returns true if the Corefile is the default for any version.",
		Example: `# See if the Corefile is the default in CoreDNS v1.4.0. 
corefile-tool default --k8sversion 1.4.0 --corefile /path/to/Corefile`,
		RunE: func(cmd *cobra.Command, args []string) error {
			k8sversion, _ := cmd.Flags().GetString("k8sversion")
			corefile, _ := cmd.Flags().GetString("corefile")

			isDefault, err := defaultCorefileFromPath(k8sversion, corefile)
			if err != nil {
				return fmt.Errorf("error while checking if the Corefile is the default: %v \n", err)
			}
			fmt.Println(isDefault)

			return nil
		},
	}
	defaultCmd.Flags().String("k8sversion", "", "The Kubernetes version for which you are checking the default.")
	defaultCmd.Flags().String("corefile", "", "Required: The path where your Corefile is located.")
	defaultCmd.MarkFlagRequired("corefile")

	return defaultCmd
}

// defaultCorefileFromPath takes the path where the Corefile is located and checks
// if the Corefile is the default for that version of Kubernetes.
func defaultCorefileFromPath(k8sVersion, corefilePath string) (bool, error) {
	fileBytes, err := getCorefileFromPath(corefilePath)
	if err != nil {
		return false, err
	}
	corefileStr := string(fileBytes)
	return migration.Default(k8sVersion, corefileStr), nil
}