refactor(course-outline): merge reorder helpers into drag utils

Author: navinkarkera

src/course-outline/OutlineTree.tsx

@@ -15,7 +15,7 @@ import {
   type SubsectionMoveDetails,
   type UnitMoveDetails,
 } from './drag-helper/utils';
-import { applyReorderMove } from './drag-helper/reorderHelpers';
+import { applyReorderMove } from './drag-helper/utils';
 
 export interface OutlineTreeProps {
   sections: XBlock[];

src/course-outline/drag-helper/reorderHelpers.ts

@@ -457,3 +457,55 @@ export const possibleUnitMoves = (
 
   return null;
 };
+
+/**
+ * Commit callback type for reorder operations.
+ * Uses variadic tuple rest to express both call signatures:
+ * - 3 params: subsection reorder  (sectionId, prevSectionId, subsectionListIds)
+ * - 4 params: unit reorder       (sectionId, prevSectionId, subsectionId, unitListIds)
+ */
+type ReorderCommitFn = (
+  sectionId: string,
+  prevSectionId: string,
+  ...rest: [string[]] | [string, string[]]
+) => void | Promise<void>;
+
+/**
+ * Apply a reorder from moveDetails and preview + commit.
+ *
+ * Handles both subsection and unit reorders. If moveDetails contains
+ * `subsectionId` the unit commit signature is used; otherwise the
+ * subsection commit signature is used.
+ */
+export function applyReorderMove(
+  moveDetails: SubsectionMoveDetails | null,
+  currentSection: XBlock,
+  previewSections: (sections: XBlock[]) => void,
+  commitReorder: ReorderCommitFn,
+): void;
+export function applyReorderMove(
+  moveDetails: UnitMoveDetails | null,
+  currentSection: XBlock,
+  previewSections: (sections: XBlock[]) => void,
+  commitReorder: ReorderCommitFn,
+): void;
+export function applyReorderMove(
+  moveDetails: MoveDetails | null,
+  currentSection: XBlock,
+  previewSections: (sections: XBlock[]) => void,
+  commitReorder: ReorderCommitFn,
+): void {
+  if (!moveDetails) { return; }
+  const { fn, args, sectionId, subsectionId } = moveDetails;
+  const [sectionsCopy, newItems] = fn(...args);
+  if (!newItems || !sectionId) { return; }
+  previewSections(sectionsCopy);
+  const ids = newItems.map((s: XBlock) => s.id);
+  if (subsectionId) {
+    // Unit reorder
+    commitReorder(sectionId, currentSection.id, subsectionId, ids);
+  } else {
+    // Subsection reorder
+    commitReorder(sectionId, currentSection.id, ids);
+  }
+}

src/course-outline/drag-helper/utils.ts

@@ -14,7 +14,7 @@ import { useCourseOutlineContext } from '@src/course-outline/CourseOutlineContex
 import { useOutlineSidebarContext } from '@src/course-outline/outline-sidebar/OutlineSidebarContext';
 import { getLibraryId } from '@src/generic/key-utils';
 import { possibleSubsectionMoves } from '@src/course-outline/drag-helper/utils';
-import { applyReorderMove } from '@src/course-outline/drag-helper/reorderHelpers';
+import { applyReorderMove } from '@src/course-outline/drag-helper/utils';
 import { XBlock } from '@src/data/types';
 
 import { InfoSection } from './InfoSection';

src/course-outline/outline-sidebar/info-sidebar/SubsectionInfoSidebar.tsx

@@ -28,7 +28,7 @@ import { Link, useNavigate } from 'react-router-dom';
 import { getLibraryId } from '@src/generic/key-utils';
 import { extractCourseUnitId } from '@src/course-unit/legacy-sidebar/utils';
 import { possibleUnitMoves } from '@src/course-outline/drag-helper/utils';
-import { applyReorderMove } from '@src/course-outline/drag-helper/reorderHelpers';
+import { applyReorderMove } from '@src/course-outline/drag-helper/utils';
 import { GenericUnitInfoSettings } from '@src/course-unit/unit-sidebar/unit-info/GenericUnitInfoSettings';
 import { useQueryClient } from '@tanstack/react-query';
 import { useOutlineSidebarContext } from '../OutlineSidebarContext';