fix: course-management practice detail without sub_module_practices row

- resolveCourseManagementPractice falls back to SUB_MODULE PRACTICE question_sets
- Synthetic practice uses id 0 and question_set_id for orphan sets
- Align GET practice and /detail with resolver; sync question_count after load

Made-with: Cursor

internal/web_server/handlers/hierarchy_handler.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"context"
 	dbgen "Yimaru-Backend/gen/db"
 	"Yimaru-Backend/internal/domain"
 	"errors"
@@ -2244,9 +2245,62 @@ func (h *Handler) GetSubModulePractices(c *fiber.Ctx) error {
 	})
 }
 
+func practiceRowFromSubModuleQuestionSet(qs domain.QuestionSet) dbgen.GetSubModulePracticeByIDRow {
+	row := dbgen.GetSubModulePracticeByIDRow{
+		ID:            0,
+		Title:         qs.Title,
+		QuestionSetID: qs.ID,
+		DisplayOrder:  0,
+		Status:        qs.Status,
+		SetType:       qs.SetType,
+		IsActive:      !strings.EqualFold(qs.Status, "ARCHIVED"),
+	}
+	if qs.OwnerID != nil {
+		row.SubModuleID = *qs.OwnerID
+	}
+	if qs.Description != nil {
+		row.Description = pgtype.Text{String: *qs.Description, Valid: true}
+	}
+	if qs.IntroVideoURL != nil {
+		row.IntroVideoUrl = pgtype.Text{String: *qs.IntroVideoURL, Valid: true}
+	}
+	return row
+}
+
+// resolveCourseManagementPractice loads an active sub_module_practices row, or a SUB_MODULE-owned PRACTICE
+// question_set with no bridge row (id is always question_sets.id in that case).
+func (h *Handler) resolveCourseManagementPractice(ctx context.Context, id int64) (dbgen.GetSubModulePracticeByIDRow, error) {
+	row, err := h.analyticsDB.GetSubModulePracticeByID(ctx, id)
+	if err == nil {
+		return row, nil
+	}
+	if !errors.Is(err, pgx.ErrNoRows) {
+		return dbgen.GetSubModulePracticeByIDRow{}, err
+	}
+	qs, err := h.questionsSvc.GetQuestionSetByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return dbgen.GetSubModulePracticeByIDRow{}, pgx.ErrNoRows
+		}
+		return dbgen.GetSubModulePracticeByIDRow{}, err
+	}
+	if !strings.EqualFold(qs.SetType, string(domain.QuestionSetTypePractice)) {
+		return dbgen.GetSubModulePracticeByIDRow{}, pgx.ErrNoRows
+	}
+	if qs.OwnerType == nil || !strings.EqualFold(*qs.OwnerType, "SUB_MODULE") || qs.OwnerID == nil {
+		return dbgen.GetSubModulePracticeByIDRow{}, pgx.ErrNoRows
+	}
+	out := practiceRowFromSubModuleQuestionSet(qs)
+	_, total, err := h.questionsSvc.GetQuestionSetItemsPaginated(ctx, qs.ID, nil, 1, 0)
+	if err == nil {
+		out.QuestionCount = total
+	}
+	return out, nil
+}
+
 // GetSubModulePracticeByID godoc
 // @Summary Get practice detail
-// @Description Returns one active practice. practiceId may be sub_module_practices.id or the linked question_sets.id.
+// @Description Returns one practice. practiceId may be sub_module_practices.id, question_sets.id, or (if no bridge row) a SUB_MODULE PRACTICE question set id.
 // @Tags course-management
 // @Accept json
 // @Produce json
@@ -2265,10 +2319,16 @@ func (h *Handler) GetSubModulePracticeByID(c *fiber.Ctx) error {
 		})
 	}
 
-	practice, err := h.analyticsDB.GetSubModulePracticeByID(c.Context(), practiceID)
+	practice, err := h.resolveCourseManagementPractice(c.Context(), practiceID)
 	if err != nil {
-		return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
+		if errors.Is(err, pgx.ErrNoRows) {
-			Message: "Practice not found",
+			return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
+				Message: "Practice not found",
+				Error:   err.Error(),
+			})
+		}
+		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
+			Message: "Failed to load practice",
 			Error:   err.Error(),
 		})
 	}
@@ -2283,7 +2343,7 @@ func (h *Handler) GetSubModulePracticeByID(c *fiber.Ctx) error {
 
 // GetSubModulePracticeDetail godoc
 // @Summary Get practice with full question list
-// @Description Returns one active practice with question-set fields and the ordered question list (full item detail). practiceId may be sub_module_practices.id or the linked question_sets.id.
+// @Description Returns practice metadata and ordered questions. practiceId may be sub_module_practices.id, linked question_sets.id, or a SUB_MODULE PRACTICE set id when no sub_module_practices row exists.
 // @Tags course-management
 // @Produce json
 // @Param practiceId path int true "Practice row id or question set id"
@@ -2300,16 +2360,23 @@ func (h *Handler) GetSubModulePracticeDetail(c *fiber.Ctx) error {
 			Error:   "practiceId must be a positive integer",
 		})
 	}
-	practice, err := h.analyticsDB.GetSubModulePracticeByID(c.Context(), practiceID)
+	practice, err := h.resolveCourseManagementPractice(c.Context(), practiceID)
 	if err != nil {
-		return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
+		if errors.Is(err, pgx.ErrNoRows) {
-			Message: "Practice not found",
+			return c.Status(fiber.StatusNotFound).JSON(domain.ErrorResponse{
+				Message: "Practice not found",
+				Error:   err.Error(),
+			})
+		}
+		return c.Status(fiber.StatusInternalServerError).JSON(domain.ErrorResponse{
+			Message: "Failed to load practice",
 			Error:   err.Error(),
 		})
 	}
 	const pageSize int32 = 500
 	var allItems []domain.QuestionSetItemWithQuestion
 	var offset int32
+	var totalCount int64
 	for {
 		batch, total, err := h.questionsSvc.GetQuestionSetItemsPaginated(c.Context(), practice.QuestionSetID, nil, pageSize, offset)
 		if err != nil {
@@ -2318,12 +2385,14 @@ func (h *Handler) GetSubModulePracticeDetail(c *fiber.Ctx) error {
 				Error:   err.Error(),
 			})
 		}
+		totalCount = total
 		allItems = append(allItems, batch...)
 		if int64(len(allItems)) >= total || len(batch) == 0 {
 			break
 		}
 		offset += pageSize
 	}
+	practice.QuestionCount = totalCount
 	return c.JSON(domain.Response{
 		Message:    "Practice retrieved successfully",
 		Success:    true,