package cmd

import (
	"fmt"
	"strconv"
	"strings"

	u "github.com/bcicen/go-units"
	"github.com/spf13/cobra"
)

// unitsCmd represents the units command
var unitsCmd = &cobra.Command{
	Use:     "units FROM TO VALUE",
	Aliases: []string{"u", "unit"},
	Short:   "converts your value from and to your given units",
	Long:    `will search for units matching from and to and convert your value accordingly`,
	Args:    cobra.MatchAll(cobra.ExactArgs(3), cobra.OnlyValidArgs),
	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
		if len(args) >= 2 {
			return nil, cobra.ShellCompDirectiveNoFileComp
		}
		return getUnitNames(toComplete), cobra.ShellCompDirectiveNoFileComp
	},
	Run: func(cmd *cobra.Command, args []string) {
		in, err := strconv.ParseFloat(args[2], 64)
		if err != nil {
			fmt.Println(err.Error())
			return
		}
		fromVal, err := u.Find(args[0])
		if err != nil {
			fmt.Println(err.Error())
			return
		}
		toVal, err := u.Find(args[1])
		if err != nil {
			fmt.Println(err.Error())
			return
		}
		val := u.NewValue(in, fromVal)
		out, err := val.Convert(toVal)
		if err != nil {
			fmt.Println(err.Error())
			return
		}
		fmt.Println(out.String())
	},
}

func getUnitNames(in string) []string {
	out := []string{}
	for _, name := range u.All() {
		if in == "" {
			out = append(out, name.Names()...)
		} else {
			for _, n := range name.Names() {
				if strings.HasPrefix(n, in) {
					out = append(out, n)
				}
			}
		}
	}
	return out
}

func init() {
	rootCmd.AddCommand(unitsCmd)
}