feat: add undo/redo, fix Outlook OAuth session loss, fix Microsoft To-Do task import

Undo/Redo:
- Add undo/redo stacks tracking task and someday list state snapshots
- Undo/redo buttons appear on hover in header center section
- Keyboard shortcuts: Ctrl+Z (undo), Ctrl+Y / Ctrl+Shift+Z (redo)
- Snapshots taken before addTask, toggleTask, updateTask, deleteTask, toggleTaskRolling

Outlook OAuth fix:
- Redirect through /auth/oauth-complete client-side page instead of directly to /tasks
- Client page calls session.update() to refresh JWT before navigating
- Prevents session loss caused by SameSite cookie policy during cross-origin redirect

Microsoft To-Do import fix:
- Set externalId and externalProvider on SomedayList during import
- Link existing lists missing external metadata on re-import
- Enables pull-sync to find and update tasks in subsequent syncs

v1.2.0

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.1.1",
+  "version": "1.2.0",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {

src/app/api/calendar/outlook/callback/route.ts

@@ -87,9 +87,18 @@ export async function GET(request: NextRequest) {
             });
         }
 
-        return NextResponse.redirect(new URL('/tasks?calendar=connected', request.url));
+        // Redirect to a client-side page that re-establishes the session
+        // Direct redirects from Microsoft OAuth may lose the session cookie (SameSite policy)
+        const redirectUrl = new URL('/auth/oauth-complete', request.url);
+        redirectUrl.searchParams.set('provider', 'outlook');
+        redirectUrl.searchParams.set('status', 'connected');
+        return NextResponse.redirect(redirectUrl);
     } catch (error) {
         console.error('Error in Outlook callback:', error);
-        return NextResponse.redirect(new URL('/auth/login?error=outlook_callback_failed', request.url));
+        const redirectUrl = new URL('/auth/oauth-complete', request.url);
+        redirectUrl.searchParams.set('provider', 'outlook');
+        redirectUrl.searchParams.set('status', 'error');
+        redirectUrl.searchParams.set('message', 'outlook_callback_failed');
+        return NextResponse.redirect(redirectUrl);
     }
 }

src/app/api/tasks/import/route.ts

@@ -176,17 +176,52 @@ export async function POST(req: NextRequest) {
         // Tasks that need parent linking after creation
         const pendingParentLinks: { localId: string; parentExternalId: string }[] = [];
 
+        // Build a lookup from list title to source list info (id, title)
+        const listTitleToSource = new Map<string, SourceList>();
+        for (const tl of targetLists) {
+            listTitleToSource.set(tl.title, tl);
+        }
+
         for (const [listTitle, tasks] of tasksByList) {
-            let somedayList = await prisma.somedayList.findFirst({
+            const sourceInfo = listTitleToSource.get(listTitle);
+
+            // Try to find by externalId first (more reliable), then by title
+            let somedayList = sourceInfo
+                ? await prisma.somedayList.findFirst({
+                    where: { userId: user.id, externalId: sourceInfo.id, externalProvider: provider }
+                })
+                : null;
+
+            if (!somedayList) {
+                somedayList = await prisma.somedayList.findFirst({
                     where: { userId: user.id, title: listTitle }
                 });
+            }
 
             if (!somedayList) {
                 somedayList = await prisma.somedayList.create({
-                    data: { userId: user.id, title: listTitle, order: 0 }
+                    data: {
+                        userId: user.id,
+                        title: listTitle,
+                        order: 0,
+                        externalId: sourceInfo?.id ?? null,
+                        externalProvider: sourceInfo ? provider : null,
+                        lastSyncedAt: new Date(),
+                    }
                 });
                 listsCreated++;
-                console.log(`[IMPORT] Created SomedayList "${listTitle}" (${somedayList.id})`);
+                console.log(`[IMPORT] Created SomedayList "${listTitle}" (${somedayList.id}) with externalId=${sourceInfo?.id}`);
+            } else if (sourceInfo && !somedayList.externalId) {
+                // Update existing list with external link if missing
+                somedayList = await prisma.somedayList.update({
+                    where: { id: somedayList.id },
+                    data: {
+                        externalId: sourceInfo.id,
+                        externalProvider: provider,
+                        lastSyncedAt: new Date(),
+                    }
+                });
+                console.log(`[IMPORT] Linked SomedayList "${listTitle}" to external ${sourceInfo.id}`);
             }
 
             // First pass: create/update all tasks (parents first via sorting)

src/app/auth/oauth-complete/page.tsx

@@ -0,0 +1,54 @@
+"use client";
+
+import { useEffect } from "react";
+import { useRouter, useSearchParams } from "next/navigation";
+import { useSession } from "next-auth/react";
+
+export default function OAuthCompletePage() {
+    const router = useRouter();
+    const searchParams = useSearchParams();
+    const { update } = useSession();
+
+    useEffect(() => {
+        async function completeOAuth() {
+            const status = searchParams.get("status");
+            const provider = searchParams.get("provider");
+
+            // Force NextAuth to refresh the session token
+            await update();
+
+            if (status === "connected") {
+                router.replace(`/tasks?calendar=${provider}_connected`);
+            } else {
+                const message = searchParams.get("message") || "connection_failed";
+                router.replace(`/tasks?error=${message}`);
+            }
+        }
+
+        completeOAuth();
+    }, [router, searchParams, update]);
+
+    return (
+        <div style={{
+            display: "flex",
+            justifyContent: "center",
+            alignItems: "center",
+            height: "100vh",
+            fontFamily: "Inter, sans-serif",
+        }}>
+            <div style={{ textAlign: "center" }}>
+                <div style={{
+                    width: "24px",
+                    height: "24px",
+                    border: "3px solid rgba(0,0,0,0.1)",
+                    borderTopColor: "#3b82f6",
+                    borderRadius: "50%",
+                    animation: "spin 0.8s linear infinite",
+                    margin: "0 auto 16px",
+                }} />
+                <p style={{ color: "#6b7280" }}>Completing connection...</p>
+                <style>{`@keyframes spin { to { transform: rotate(360deg); } }`}</style>
+            </div>
+        </div>
+    );
+}

src/components/WeeklyView.tsx

@@ -40,6 +40,8 @@ import {
     Sparkles,
     Info,
     Trash2,
+    Undo2,
+    Redo2,
 } from "lucide-react";
 
 // Types
@@ -493,6 +495,13 @@ export default function WeeklyView() {
     const [editingTaskId, setEditingTaskId] = useState<string | null>(null);
     const [draggingListId, setDraggingListId] = useState<string | null>(null);
 
+    // Undo/Redo state
+    const undoStackRef = useRef<{ tasks: Task[]; somedayLists: SomedayList[] }[]>([]);
+    const redoStackRef = useRef<{ tasks: Task[]; somedayLists: SomedayList[] }[]>([]);
+    const [undoCount, setUndoCount] = useState(0);
+    const [redoCount, setRedoCount] = useState(0);
+    const skipSnapshotRef = useRef(false);
+
     // Moved state definitions to the top
     const [showSettings, setShowSettings] = useState(false);
     const [activeTab, setActiveTab] = useState<
@@ -1987,9 +1996,71 @@ export default function WeeklyView() {
         setImportProvider(null);
     };
 
+    // Undo/Redo helpers
+    const saveSnapshot = useCallback(() => {
+        if (skipSnapshotRef.current) return;
+        undoStackRef.current = [
+            ...undoStackRef.current.slice(-29), // keep last 30 snapshots
+            {
+                tasks: JSON.parse(JSON.stringify(tasks)),
+                somedayLists: JSON.parse(JSON.stringify(somedayLists)),
+            },
+        ];
+        redoStackRef.current = [];
+        setUndoCount(undoStackRef.current.length);
+        setRedoCount(0);
+    }, [tasks, somedayLists]);
+
+    const handleUndo = useCallback(() => {
+        if (undoStackRef.current.length === 0) return;
+        const snapshot = undoStackRef.current.pop()!;
+        redoStackRef.current.push({
+            tasks: JSON.parse(JSON.stringify(tasks)),
+            somedayLists: JSON.parse(JSON.stringify(somedayLists)),
+        });
+        skipSnapshotRef.current = true;
+        setTasks(snapshot.tasks);
+        setSomedayLists(snapshot.somedayLists);
+        skipSnapshotRef.current = false;
+        setUndoCount(undoStackRef.current.length);
+        setRedoCount(redoStackRef.current.length);
+    }, [tasks, somedayLists]);
+
+    const handleRedo = useCallback(() => {
+        if (redoStackRef.current.length === 0) return;
+        const snapshot = redoStackRef.current.pop()!;
+        undoStackRef.current.push({
+            tasks: JSON.parse(JSON.stringify(tasks)),
+            somedayLists: JSON.parse(JSON.stringify(somedayLists)),
+        });
+        skipSnapshotRef.current = true;
+        setTasks(snapshot.tasks);
+        setSomedayLists(snapshot.somedayLists);
+        skipSnapshotRef.current = false;
+        setUndoCount(undoStackRef.current.length);
+        setRedoCount(redoStackRef.current.length);
+    }, [tasks, somedayLists]);
+
+    // Keyboard shortcuts for undo/redo
+    useEffect(() => {
+        const handleKeyDown = (e: KeyboardEvent) => {
+            if ((e.ctrlKey || e.metaKey) && e.key === "z" && !e.shiftKey) {
+                e.preventDefault();
+                handleUndo();
+            }
+            if ((e.ctrlKey || e.metaKey) && (e.key === "y" || (e.key === "z" && e.shiftKey))) {
+                e.preventDefault();
+                handleRedo();
+            }
+        };
+        window.addEventListener("keydown", handleKeyDown);
+        return () => window.removeEventListener("keydown", handleKeyDown);
+    }, [handleUndo, handleRedo]);
+
     // Task CRUD operations
     const addTask = async (date: Date, title: string, startTime?: string) => {
         if (!title.trim()) return;
+        saveSnapshot();
 
         const scheduledDate = formatDateToISO(date); // Use local date formatting
 
@@ -2058,6 +2129,7 @@ export default function WeeklyView() {
     };
 
     const toggleTask = async (taskId: string) => {
+        saveSnapshot();
         const task = findTaskAnywhere(taskId);
         if (!task) return;
 
@@ -2105,6 +2177,7 @@ export default function WeeklyView() {
     };
 
     const updateTask = async (taskId: string, newTitle: string) => {
+        saveSnapshot();
         if (!newTitle.trim()) {
             await deleteTask(taskId);
             return;
@@ -2413,6 +2486,7 @@ export default function WeeklyView() {
     };
 
     const toggleTaskRolling = async (taskId: string) => {
+        saveSnapshot();
         const task = findTaskAnywhere(taskId);
         if (!task) return;
 
@@ -2517,6 +2591,7 @@ export default function WeeklyView() {
     };
 
     const deleteTask = async (taskId: string) => {
+        saveSnapshot();
         const taskToDelete = findTaskAnywhere(taskId);
         const isSomeday = !!taskToDelete?.somedayListId;
         const isVirtual = taskId.startsWith("virtual-");
@@ -3326,6 +3401,22 @@ export default function WeeklyView() {
                                 <RefreshCcw size={14} />
                             </button>
                         )}
+                        <button
+                            onClick={handleUndo}
+                            disabled={undoCount === 0}
+                            className="p-1 rounded-full hover:bg-gray-100 dark:hover:bg-gray-800 transition-all text-gray-400 hover:text-gray-600 opacity-0 group-hover:opacity-100 disabled:opacity-0 disabled:cursor-default"
+                            title="Undo (Ctrl+Z)"
+                        >
+                            <Undo2 size={14} />
+                        </button>
+                        <button
+                            onClick={handleRedo}
+                            disabled={redoCount === 0}
+                            className="p-1 rounded-full hover:bg-gray-100 dark:hover:bg-gray-800 transition-all text-gray-400 hover:text-gray-600 opacity-0 group-hover:opacity-100 disabled:opacity-0 disabled:cursor-default"
+                            title="Redo (Ctrl+Y)"
+                        >
+                            <Redo2 size={14} />
+                        </button>
                         <span style={{
                             fontFamily: profile.cwFontFamily || "Inter",
                             fontSize: profile.cwFontSize || "1.125rem",