merge services api and nginx

serv_nginx/serv_golang_rest_api/internal/utils/json.go

@@ -0,0 +1,115 @@
+// utils/json.go
+package utils
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// DecodeJSON декодирует JSON из тела запроса с валидацией
+func DecodeJSON(r *http.Request, v interface{}) error {
+	// Ограничиваем размер тела запроса (например, 1MB)
+	maxBytes := int64(1_048_576) // 1MB
+	r.Body = http.MaxBytesReader(nil, r.Body, maxBytes)
+
+	decoder := json.NewDecoder(r.Body)
+	decoder.DisallowUnknownFields() // Запрещаем неизвестные поля
+
+	err := decoder.Decode(v)
+	if err != nil {
+		var syntaxError *json.SyntaxError
+		var unmarshalTypeError *json.UnmarshalTypeError
+		var invalidUnmarshalError *json.InvalidUnmarshalError
+
+		switch {
+		case err == io.EOF:
+			return &APIError{
+				Code:    http.StatusBadRequest,
+				Message: "Request body is empty",
+			}
+		case err.Error() == "http: request body too large":
+			return &APIError{
+				Code:    http.StatusRequestEntityTooLarge,
+				Message: fmt.Sprintf("Request body must not be larger than %d bytes", maxBytes),
+			}
+		case strings.HasPrefix(err.Error(), "json: unknown field"):
+			fieldName := strings.TrimPrefix(err.Error(), "json: unknown field ")
+			return &APIError{
+				Code:    http.StatusBadRequest,
+				Message: fmt.Sprintf("Unknown field in JSON: %s", fieldName),
+			}
+		case errors.As(err, &syntaxError):
+			return &APIError{
+				Code:    http.StatusBadRequest,
+				Message: fmt.Sprintf("Malformed JSON at position %d", syntaxError.Offset),
+			}
+		case errors.As(err, &unmarshalTypeError):
+			return &APIError{
+				Code:    http.StatusBadRequest,
+				Message: fmt.Sprintf("Invalid value for field '%s'. Expected type %s", unmarshalTypeError.Field, unmarshalTypeError.Type),
+			}
+		case errors.As(err, &invalidUnmarshalError):
+			return &APIError{
+				Code:    http.StatusInternalServerError,
+				Message: "Internal server error",
+			}
+		default:
+			return &APIError{
+				Code:    http.StatusBadRequest,
+				Message: "Invalid JSON",
+			}
+		}
+	}
+
+	// Проверяем, что нет лишних данных после JSON
+	if err = decoder.Decode(&struct{}{}); err != io.EOF {
+		return &APIError{
+			Code:    http.StatusBadRequest,
+			Message: "Request body must contain only single JSON object",
+		}
+	}
+
+	return nil
+}
+
+// WriteJSON записывает JSON ответ
+func WriteJSON(w http.ResponseWriter, status int, data interface{}) error {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+
+	if data == nil {
+		return nil
+	}
+
+	encoder := json.NewEncoder(w)
+	encoder.SetEscapeHTML(true) // Экранируем HTML для безопасности
+
+	return encoder.Encode(data)
+}
+
+// WriteError записывает ошибку в формате JSON
+func WriteError(w http.ResponseWriter, status int, message string) {
+	errorResponse := ErrorResponse{
+		Error:   true,
+		Message: message,
+		Code:    status,
+	}
+
+	WriteJSON(w, status, errorResponse)
+}
+
+// WriteValidationError записывает ошибки валидации
+func WriteValidationError(w http.ResponseWriter, errors map[string]string) {
+	errorResponse := ValidationErrorResponse{
+		Error:   true,
+		Message: "Validation failed",
+		Code:    http.StatusBadRequest,
+		Errors:  errors,
+	}
+
+	WriteJSON(w, http.StatusBadRequest, errorResponse)
+}