feat: add inline buttons to traffic command

botcmd_exchangerates.go

@@ -0,0 +1,170 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"git.gensokyo.cafe/kkyy/mycurrencynet"
+	"github.com/dustin/go-humanize"
+	"github.com/go-errors/errors"
+	"github.com/samber/lo"
+	tele "gopkg.in/telebot.v3"
+)
+
+func handleExchangeRateCmd(c tele.Context) error {
+	msg := c.Message()
+	if msg == nil {
+		return nil
+	}
+
+	if msg.Payload == "" {
+		return c.Reply("Usage: `/xr <currency> [<currency> ...] [to] <currency>`",
+			&tele.SendOptions{ParseMode: tele.ModeMarkdown},
+			tele.Silent,
+		)
+	}
+
+	from, to, err := parseXrRequest(msg.Payload)
+	if err != nil {
+		return c.Reply(err.Error(), tele.Silent)
+	}
+	codes := append([]string{to.Code}, lo.Map(from, func(i xrCurrency, _ int) string { return i.Code })...)
+	currencies, err := exchangeRates.Get(codes...)
+	if err != nil {
+		return c.Reply(err.Error(), tele.Silent)
+	}
+	toCur := currencies[0]
+
+	// format reply
+	var replyLines []string
+	for i, fromItem := range from {
+		fromCur := currencies[i+1]
+		replyLines = append(replyLines, fmtXrPair(fromCur, toCur, fromItem.Amount))
+	}
+
+	return c.Reply(strings.Join(replyLines, "\n"), &tele.SendOptions{ParseMode: tele.ModeMarkdown}, tele.Silent)
+}
+
+type xrCurrency struct {
+	Code   string
+	Amount float64
+}
+
+func parseXrRequest(input string) (from []xrCurrency, to xrCurrency, err error) {
+	args := strings.Fields(input)
+
+	var tmpTo *xrCurrency = nil
+	fillFrom := true
+
+	c := xrCurrency{Amount: -1}
+	for _, arg := range args {
+		arg = strings.ToUpper(arg)
+
+		switch {
+		case arg == "TO":
+			fillFrom = false
+			continue
+
+		case fillFrom:
+			num, sym, tErr := parseXrToken(arg)
+			if tErr != nil {
+				err = tErr
+				return
+			}
+			if num != -1 {
+				if c.Amount != -1 {
+					err = errors.New("invalid input")
+					return
+				}
+				c.Amount = num
+			}
+			if c.Amount == -1 {
+				c.Amount = 1
+			}
+
+			if sym != "" {
+				c.Code = sym
+				from = append(from, c)
+				c = xrCurrency{Amount: -1}
+			}
+
+		case !fillFrom:
+			if tmpTo != nil {
+				err = errors.New("invalid input")
+				return
+			}
+			tmpTo = &xrCurrency{Code: arg}
+
+		default:
+			err = errors.New("invalid input")
+			return
+		}
+	}
+
+	if len(from) < 1 || len(from) > 10 {
+		err = errors.New("invalid input")
+		return
+	}
+
+	if fillFrom {
+		if len(from) < 2 {
+			err = errors.New("invalid input")
+			return
+		}
+		tmpTo = &from[len(from)-1]
+		from = from[:len(from)-1]
+	}
+
+	if tmpTo == nil {
+		err = errors.New("invalid input")
+		return
+	}
+	to = *tmpTo
+
+	return
+}
+
+var xrTokenRe = regexp.MustCompile(`^([0-9.]+)?([A-Z]{3,})?$`)
+
+func parseXrToken(token string) (num float64, sym string, err error) {
+	num = -1
+	matches := xrTokenRe.FindStringSubmatch(token)
+	if len(matches) != 3 {
+		err = errors.New("invalid input")
+		return
+	}
+
+	if matches[1] != "" {
+		num, err = strconv.ParseFloat(matches[1], 64)
+		if err != nil {
+			return
+		}
+		if num <= 0 {
+			err = errors.New("invalid input: amount must be positive")
+			return
+		}
+	}
+
+	sym = matches[2]
+	if num == 0 && sym == "" {
+		err = errors.New("invalid input")
+	}
+	return
+}
+
+func fmtXrPair(from, to *mycurrencynet.Currency, amount float64) string {
+	rate := from.To(to) * amount
+	fromInfo := fmt.Sprintf("%s (%s)", from.Name, from.Code)
+	toInfo := fmt.Sprintf("%s (%s)", to.Name, to.Code)
+
+	return fmt.Sprintf("*%s* %s\n= *%s* %s\n", fmtXrFloat(amount), fromInfo, fmtXrFloat(rate), toInfo)
+}
+
+func fmtXrFloat(num float64) string {
+	if num < 100 {
+		return fmt.Sprintf("%.4g", num)
+	}
+	return humanize.CommafWithDigits(num, 2)
+}