reinstate profit loss overview

internal/service/analytics_service_test.go

@@ -154,6 +154,16 @@ func TestAnalyticsServiceGetProfitLossAnalyticsValidation(t *testing.T) {
 			},
 			wantErr: "date_from cannot be after date_to",
 		},
+		{
+			name: "invalid group_by",
+			req: &models.ProfitLossAnalyticsRequest{
+				OrganizationID: uuid.New(),
+				DateFrom:       now,
+				DateTo:         now,
+				GroupBy:        "quarter",
+			},
+			wantErr: "invalid group_by value: quarter",
+		},
 	}
 
 	for _, tt := range tests {
@@ -166,3 +176,17 @@ func TestAnalyticsServiceGetProfitLossAnalyticsValidation(t *testing.T) {
 		})
 	}
 }
+
+func TestAnalyticsServiceGetProfitLossAnalyticsAllowsEmptyGroupBy(t *testing.T) {
+	service := NewAnalyticsServiceImpl(analyticsProcessorStub{})
+	now := time.Date(2026, 5, 1, 0, 0, 0, 0, time.UTC)
+
+	resp, err := service.GetProfitLossAnalytics(context.Background(), &models.ProfitLossAnalyticsRequest{
+		OrganizationID: uuid.New(),
+		DateFrom:       now,
+		DateTo:         now,
+	})
+
+	require.NoError(t, err)
+	require.Nil(t, resp)
+}