price command

cmd/price.go

@@ -0,0 +1,100 @@
+package cmd
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sort"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/kf5grd/keybasebot"
+	"github.com/teris-io/shortid"
+	"samhofi.us/x/keybase/v2/types/chat1"
+)
+
+var PriceAd = chat1.UserBotCommandInput{
+	Name:        "price",
+	Usage:       "<cryptocurrency>",
+	Description: "Gets lowest crypto prices",
+}
+
+func SendPrice(m chat1.MsgSummary, b *keybasebot.Bot) (bool, error) {
+	fields := strings.Fields(strings.TrimSpace(strings.Replace(m.Content.Text.Body, "!price", "", 1)))
+
+	// first pass filtering
+	if fields == nil || len(fields) > 2 {
+		return true, fmt.Errorf("Invalid Request")
+	}
+	// get the args
+	currency := strings.ToUpper(fields[0])
+	var target string
+	if len(fields) == 2 {
+		target = strings.ToUpper(fields[1])
+	} else {
+		target = "USD"
+	}
+	// validate the args
+	if !isAlpha(currency) || !isAlpha(target) {
+		return true, fmt.Errorf("@%s - only letters are allowed in currency symbols", m.Sender.Username)
+	}
+	// get all the market prices
+	prices, err := getPrices(currency, target)
+	if err != nil {
+		eid := shortid.MustGenerate()
+		b.Logger.Error("%s: %+v", eid, err)
+		b.KB.ReactByConvID(m.ConvID, m.Id, "Error: %s", eid)
+		return true, nil
+	}
+	// sort them by price
+	sort.Slice(prices, func(i, j int) bool { return prices[i].Price < prices[j].Price })
+	// get the top 5 best prices
+	var numPrices int
+	if len(prices) > 5 {
+		numPrices = 5
+	} else if len(prices) > 0 {
+		numPrices = len(prices)
+	} else {
+		return true, fmt.Errorf("@%s - no exchanges list %s", m.Sender.Username, currency)
+	}
+	// then use a tabwriter to format the output
+	var buf bytes.Buffer
+	w := tabwriter.NewWriter(&buf, 0, 0, 1, ' ', tabwriter.AlignRight)
+	fmt.Fprintf(w, "@%s - Lowest %s Prices:```\n", m.Sender.Username, currency)
+	for _, price := range prices[:numPrices] {
+		fmt.Fprintf(w, "%s:\t%s\t%s\t\n", price.Market, price.Price, target)
+	}
+	fmt.Fprintln(w, "```")
+	w.Flush()
+	b.KB.SendMessageByConvID(m.ConvID, buf.String())
+	return true, nil
+}
+
+func getPrices(currency string, target string) ([]CryptonatorMarket, error) {
+	client := &http.Client{}
+	apiTargetURL := fmt.Sprintf("https://api.cryptonator.com/api/full/%s-%s", currency, target)
+	req, err := http.NewRequest("GET", apiTargetURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("User-Agent", "GoLang Currency Bot ssh0le/0.99")
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	var apiResponse CryptApiResponse
+	if err := json.Unmarshal(body, &apiResponse); err != nil {
+		return nil, err
+	}
+	if !apiResponse.Success {
+		return nil, fmt.Errorf(apiResponse.Error)
+	}
+	return apiResponse.Ticker.Markets, nil
+}