refactor(web): extract allocation drag finalize helpers

apps/web/src/hooks/useTimelineDrag.ts

@@ -7,11 +7,16 @@ import { pixelsToDays, computeDragDates } from "~/components/timeline/dragMath.j
 import {
   captureLivePreviewTargets,
   clearLivePreview,
-  datesMatch,
   preserveLivePreview,
   scheduleLivePreview,
   type LivePreviewSession,
 } from "./timelineLivePreview.js";
+import {
+  buildAllocationMovedSnapshot,
+  hasAllocationDateChange,
+  requiresAllocationFragmentExtraction,
+  shouldTreatAllocationDragAsClick,
+} from "./timelineAllocationFinalize.js";
 import {
   createMultiSelectState,
   finalizeMultiSelectDraft,
@@ -729,23 +734,14 @@ export function useTimelineDrag({
         updateAllocationDragPosition(ev.clientX);
         const alloc = allocDragRef.current;
         if (!alloc.isActive) return;
-        const pointerDelta = Math.abs(alloc.pointerDeltaX);
-        const hasDateChange =
-          Boolean(alloc.originalStartDate && alloc.currentStartDate && alloc.originalEndDate && alloc.currentEndDate) &&
-          (
-            alloc.originalStartDate!.getTime() !== alloc.currentStartDate!.getTime() ||
-            alloc.originalEndDate!.getTime() !== alloc.currentEndDate!.getTime()
-          );
+        const hasDateChange = hasAllocationDateChange(alloc);
 
         if (hasDateChange) {
           preserveLivePreview(allocPreviewRef.current);
         }
         clearLivePreview(allocPreviewRef.current);
         allocPreviewRef.current = null;
-        const shouldTreatAsClick =
-          alloc.mode === "move" &&
-          alloc.daysDelta === 0 &&
-          pointerDelta <= DRAG_CLICK_THRESHOLD_PX;
+        const shouldTreatAsClick = shouldTreatAllocationDragAsClick(alloc, DRAG_CLICK_THRESHOLD_PX);
 
         if (shouldTreatAsClick && alloc.allocationId) {
           // No movement → treat as click
@@ -767,18 +763,9 @@ export function useTimelineDrag({
           const currentStartDate = alloc.currentStartDate;
           const currentEndDate = alloc.currentEndDate;
           const baseMutationAllocationId = alloc.mutationAllocationId ?? activeAllocationId;
-          const requiresExtraction =
-            alloc.scope === "segment" &&
-            (!datesMatch(alloc.originalStartDate, alloc.allocationStartDate) ||
-              !datesMatch(alloc.originalEndDate, alloc.allocationEndDate));
+          const requiresExtraction = requiresAllocationFragmentExtraction(alloc);
 
-          pendingSnapshotRef.current = {
-            allocationId: activeAllocationId,
-            mutationAllocationId: baseMutationAllocationId,
-            projectName: alloc.projectName ?? "",
-            before: { startDate: alloc.originalStartDate!, endDate: alloc.originalEndDate! },
-            after: { startDate: currentStartDate, endDate: currentEndDate },
-          };
+          pendingSnapshotRef.current = buildAllocationMovedSnapshot(alloc);
           pendingOptimisticAllocationIdRef.current = activeAllocationId;
           setOptimisticAllocations((prev) => {
             const next = new Map(prev);