ui calculator

pkg/storage/fs/fs.go

@@ -128,6 +128,15 @@ func (s *fsStorage) SaveStateAsync(state client.State, callback func(error)) {
 	}()
 }
 
+func (s *fsStorage) ReportExistsAsync(id client.GameID, turn uint, callback func(bool, error)) {
+	go func() {
+		exists, err := s.gameDataExistsSync(id, turn)
+		if callback != nil {
+			callback(exists, err)
+		}
+	}()
+}
+
 func (s *fsStorage) LoadReportAsync(id client.GameID, turn uint, callback func(report.Report, error)) {
 	go func() {
 		rep, err := s.loadReportSync(id, turn)
@@ -343,6 +352,20 @@ func (s *fsStorage) saveOrderSync(id client.GameID, turn uint, o order.Order) er
 	}))
 }
 
+func (s *fsStorage) gameDataExistsSync(id client.GameID, turn uint) (bool, error) {
+	absPath, err := s.resolvePath(gameTurnFilePath(id, turn))
+	if err != nil {
+		return false, classifyStorageError(err)
+	}
+
+	exists, err := s.fileExistsUnlocked(absPath)
+	if err != nil {
+		return false, classifyStorageError(err)
+	}
+
+	return exists, nil
+}
+
 func (s *fsStorage) loadGameDataSync(id client.GameID, turn uint) (client.GameData, error) {
 	absPath, err := s.resolvePath(gameTurnFilePath(id, turn))
 	if err != nil {

pkg/storage/storage.go

@@ -36,6 +36,11 @@ type UIStorage interface {
 	// I/O or encoding error may occur, it that case callback func will be called with non-nil error.
 	SaveStateAsync(client.State, func(error))
 
+	// ReportExistsAsync asynchronously checks whether given [model.GameID] and turn number exists in the Storage.
+	// Passed callback func will will accept non-nil error in case of I/O or decoding errors occuried,
+	// otherwise callback func accepts boolean result.
+	ReportExistsAsync(client.GameID, uint, func(bool, error))
+
 	// LoadReportAsync loads a [report.Report] for a given [model.GameID] and turn number from filesystem asynchronously.
 	// Passed callback func will will accept non-nil error in case of I/O or decoding errors occuried,
 	// otherwise callback func accepts loaded [report.Report].