To gitea and beyond, let's go(-yco)

internal/middleware/validation.go

@@ -0,0 +1,79 @@
+package middleware
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"reflect"
+	"strings"
+
+	"goyco/internal/validation"
+)
+
+func ValidationMiddleware() func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.Method == "GET" || r.Method == "DELETE" || r.Method == "HEAD" || r.Method == "OPTIONS" {
+				next.ServeHTTP(w, r)
+				return
+			}
+
+			dtoType := GetDTOTypeFromContext(r.Context())
+			if dtoType == nil {
+				next.ServeHTTP(w, r)
+				return
+			}
+
+			dto := reflect.New(dtoType).Interface()
+
+			if err := json.NewDecoder(r.Body).Decode(dto); err != nil {
+				http.Error(w, "Invalid JSON", http.StatusBadRequest)
+				return
+			}
+
+			if err := validation.ValidateStruct(dto); err != nil {
+				var errorMessages []string
+				if structErr, ok := err.(*validation.StructValidationError); ok {
+					errorMessages = make([]string, len(structErr.Errors))
+					for i, fieldError := range structErr.Errors {
+						errorMessages[i] = fieldError.Message
+					}
+				} else {
+					errorMessages = []string{err.Error()}
+				}
+
+				response := map[string]any{
+					"success": false,
+					"error":   "Validation failed",
+					"details": strings.Join(errorMessages, "; "),
+				}
+
+				w.Header().Set("Content-Type", "application/json")
+				w.WriteHeader(http.StatusBadRequest)
+				json.NewEncoder(w).Encode(response)
+				return
+			}
+
+			ctx := context.WithValue(r.Context(), validatedDTOKey, dto)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+const DTOTypeKey contextKey = "dto_type"
+const validatedDTOKey contextKey = "validated_dto"
+
+func SetDTOTypeInContext(ctx context.Context, dtoType reflect.Type) context.Context {
+	return context.WithValue(ctx, DTOTypeKey, dtoType)
+}
+
+func GetDTOTypeFromContext(ctx context.Context) reflect.Type {
+	if dtoType, ok := ctx.Value(DTOTypeKey).(reflect.Type); ok {
+		return dtoType
+	}
+	return nil
+}
+
+func GetValidatedDTOFromContext(ctx context.Context) any {
+	return ctx.Value(validatedDTOKey)
+}