converter/cmd/crypto.go

/*
Copyright © 2023 NAME HERE <EMAIL ADDRESS>
*/
package cmd

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"

	"github.com/spf13/cobra"
)

type Search struct {
	Coins []struct {
		ID            string `json:"id"`
		Name          string `json:"name"`
		APISymbol     string `json:"api_symbol"`
		Symbol        string `json:"symbol"`
		MarketCapRank int    `json:"market_cap_rank"`
		Thumb         string `json:"thumb"`
		Large         string `json:"large"`
	} `json:"coins"`
}

type Price map[string]USD

type USD struct {
	Usd float64
}

var (
	price_url  = "https://api.coingecko.com/api/v3/simple/price?"
	search_url = "https://api.coingecko.com/api/v3/search?query="
)

var amount float64

// cryptoCmd represents the crypto command
var cryptoCmd = &cobra.Command{
	Use:   "crypto",
	Short: "get price of token",
	Long:  `get price of token`,
	Args:  cobra.MatchAll(cobra.RangeArgs(1, 2), cobra.OnlyValidArgs),
	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
		if len(args) >= 2 {
			return nil, cobra.ShellCompDirectiveNoFileComp
		}
		return getTokens(toComplete), cobra.ShellCompDirectiveNoFileComp
	},
	RunE: func(cmd *cobra.Command, args []string) error {
		price, err := usdPrice(args[0])
		if err != nil {
			return err
		}
		price = price * amount
		price2 := float64(1)
		if len(args) >= 2 {
			price2, err = usdPrice(args[1])
			if err != nil {
				return err
			}
		}
		fmt.Println(price / price2)
		return nil
	},
}

func getTokens(in string) []string {
	if in == "" {
		return []string{"ethereum", "bitcoin", "tether", "binancecoin", "usd-coin", "ripple", "cardano", "dogecoin", "matic-network"}
	}
	resp, err := http.Get(search_url + in)
	if err != nil {
		return []string{err.Error()}
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return []string{err.Error()}
	}
	var tokens Search
	err = json.Unmarshal(body, &tokens)
	if err != nil {
		return []string{err.Error()}
	}
	out := []string{}
	for _, token := range tokens.Coins {
		out = append(out, token.ID)
	}
	return out
}

func usdPrice(token string) (float64, error) {
	resp, err := http.Get(price_url + fmt.Sprintf("ids=%s&vs_currencies=usd", token))
	if err != nil {
		return 0, err
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return 0, err
	}
	var price Price
	err = json.Unmarshal(body, &price)
	if err != nil {
		return 0, err
	}
	return price[token].Usd, nil
}

func init() {
	rootCmd.AddCommand(cryptoCmd)
	cryptoCmd.PersistentFlags().Float64VarP(&amount, "amount", "a", 1, "amount of the given token")
}