обработка обновлений последовательно для каждого юзера благодаря mutex

telegram_bot/screens/purchase_optional_details.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"example.com/m/bot"
+	"example.com/m/ui"
 	"github.com/NicoNex/echotron/v3"
 )
 
@@ -555,15 +556,10 @@ func (s *PurchaseOptionalDetails) renderParamChannels(b *bot.Bot, mode bot.Rende
 		return
 	}
 
-	start := s.ParamPage * perPage
-	if start >= total {
+	if s.ParamPage*perPage >= total {
 		s.ParamPage = 0
-		start = 0
-	}
-	end := start + perPage
-	if end > total {
-		end = total
 	}
+	start, end := ui.GetPageBounds(s.ParamPage, perPage, total)
 
 	var rows [][]echotron.InlineKeyboardButton
 	for i := start; i < end; i++ {
@@ -577,20 +573,11 @@ func (s *PurchaseOptionalDetails) renderParamChannels(b *bot.Bot, mode bot.Rende
 		))
 	}
 
-	pages := (total + perPage - 1) / perPage
-	if pages > 1 {
-		var navRow []echotron.InlineKeyboardButton
-		if s.ParamPage > 0 {
-			navRow = append(navRow, bot.Button("←", "param_prev"))
-		} else {
-			navRow = append(navRow, bot.Button("·", "empty"))
-		}
-		navRow = append(navRow, bot.Button(fmt.Sprintf("• %d/%d •", s.ParamPage+1, pages), "page_info"))
-		if s.ParamPage+1 < pages {
-			navRow = append(navRow, bot.Button("→", "param_next"))
-		} else {
-			navRow = append(navRow, bot.Button("·", "empty"))
-		}
+	pages := ui.CalculatePages(total, perPage)
+	if navRow := ui.BuildNavigationRow(ui.PaginationConfig{
+		CurrentPage: s.ParamPage,
+		TotalPages:  pages,
+	}); navRow != nil {
 		rows = append(rows, navRow)
 	}
 
@@ -688,13 +675,13 @@ func (s *PurchaseOptionalDetails) handleParamCallback(b *bot.Bot, data string) b
 		s.applyParamToAll(param)
 		s.Enter(b, bot.EditMessage)
 		return true
-	case data == "param_prev":
+	case data == "prev" && strings.HasSuffix(s.InputMode, "_channels"):
 		if s.ParamPage > 0 {
 			s.ParamPage--
 		}
 		s.Enter(b, bot.EditMessage)
 		return true
-	case data == "param_next":
+	case data == "next" && strings.HasSuffix(s.InputMode, "_channels"):
 		s.ParamPage++
 		s.Enter(b, bot.EditMessage)
 		return true