Adds habit edit, archive, and undo log features

Enables users to update or archive habits and to undo the latest habit log.
Adds PATCH/DELETE API endpoints for habit edit and soft deletion.
Introduces UI dialogs and controls for editing and archiving habits,
as well as for undoing the most recent log entry directly from the dashboard.
Improves log statistics handling by ordering and simplifies last log detection.

app/dashboard/page.tsx

@@ -16,6 +16,10 @@ import {
   Check,
   Trophy,
   HeartCrack,
+  MoreVertical,
+  Trash2,
+  Save,
+  RotateCcw,
 } from 'lucide-react';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { Button } from '@/components/ui/button';
@@ -73,9 +77,17 @@ interface HabitResponse {
 export default function Dashboard() {
   const router = useRouter();
   const queryClient = useQueryClient();
+  
+  // State
   const [showNewHabitDialog, setShowNewHabitDialog] = useState(false);
   const [newHabitName, setNewHabitName] = useState('');
   const [newHabitType, setNewHabitType] = useState<'positive' | 'neutral' | 'negative'>('neutral');
+  
+  const [editingHabit, setEditingHabit] = useState<Habit | null>(null);
+  const [editHabitName, setEditHabitName] = useState('');
+  const [editHabitType, setEditHabitType] = useState<'positive' | 'neutral' | 'negative'>('neutral');
+  const [showDeleteConfirm, setShowDeleteConfirm] = useState(false);
+
   const [copiedToken, setCopiedToken] = useState(false);
   const [currentTime, setCurrentTime] = useState(() => Date.now());
 
@@ -92,14 +104,12 @@ export default function Dashboard() {
     },
   });
 
-  // Update current time periodically to avoid impure Date.now() calls during render
+  // Update current time periodically
   useEffect(() => {
     const interval = setInterval(() => {
       setCurrentTime(Date.now());
-    }, 60000); // Update every minute
-    return () => {
-      clearInterval(interval);
-    };
+    }, 60000);
+    return () => clearInterval(interval);
   }, []);
 
   // Fetch habits
@@ -129,6 +139,19 @@ export default function Dashboard() {
     },
   });
 
+  // Undo log mutation
+  const undoLogMutation = useMutation<void, Error, number>({
+    mutationFn: async (habitId: number): Promise<void> => {
+      const res = await fetch(`/api/habits/${habitId}/log`, {
+        method: 'DELETE',
+      });
+      if (!res.ok) throw new Error('Failed to undo log');
+    },
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: ['habits'] });
+    },
+  });
+
   // Create habit mutation
   const createHabitMutation = useMutation<HabitResponse, Error, { name: string; type: string }>({
     mutationFn: async (data: { name: string; type: string }): Promise<HabitResponse> => {
@@ -148,6 +171,38 @@ export default function Dashboard() {
     },
   });
 
+  // Update habit mutation
+  const updateHabitMutation = useMutation<HabitResponse, Error, { id: number; name: string; type: string }>({
+    mutationFn: async ({ id, name, type }): Promise<HabitResponse> => {
+      const res = await fetch(`/api/habits/${id}`, {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ name, type }),
+      });
+      if (!res.ok) throw new Error('Failed to update habit');
+      return res.json() as Promise<HabitResponse>;
+    },
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: ['habits'] });
+      setEditingHabit(null);
+    },
+  });
+
+  // Delete habit mutation
+  const deleteHabitMutation = useMutation<void, Error, number>({
+    mutationFn: async (id: number): Promise<void> => {
+      const res = await fetch(`/api/habits/${id}`, {
+        method: 'DELETE',
+      });
+      if (!res.ok) throw new Error('Failed to delete habit');
+    },
+    onSuccess: () => {
+      void queryClient.invalidateQueries({ queryKey: ['habits'] });
+      setEditingHabit(null);
+      setShowDeleteConfirm(false);
+    },
+  });
+
   const handleCreateHabit = () => {
     if (newHabitName.trim()) {
       createHabitMutation.mutate({
@@ -157,6 +212,30 @@ export default function Dashboard() {
     }
   };
 
+  const handleUpdateHabit = () => {
+    if (editingHabit && editHabitName.trim()) {
+      updateHabitMutation.mutate({
+        id: editingHabit.id,
+        name: editHabitName.trim(),
+        type: editHabitType,
+      });
+    }
+  };
+
+  const handleDeleteHabit = () => {
+    if (editingHabit) {
+      deleteHabitMutation.mutate(editingHabit.id);
+    }
+  };
+
+  const openEditDialog = (e: React.MouseEvent, habit: Habit) => {
+    e.stopPropagation();
+    setEditingHabit(habit);
+    setEditHabitName(habit.name);
+    setEditHabitType(habit.type);
+    setShowDeleteConfirm(false);
+  };
+
   const copyToken = () => {
     if (authData?.token) {
       void navigator.clipboard.writeText(authData.token);
@@ -355,7 +434,7 @@ export default function Dashboard() {
           {habits.map((habit: Habit) => (
             <Card
               key={habit.id}
-              className={`transform cursor-pointer transition-all duration-200 hover:scale-[1.02] ${getHabitCardClass(
+              className={`group relative transform cursor-pointer transition-all duration-200 hover:scale-[1.02] ${getHabitCardClass(
                 habit.type,
               )} ${logHabitMutation.isPending ? 'opacity-75' : ''}`}
               onClick={() => {
@@ -365,19 +444,53 @@ export default function Dashboard() {
               <CardHeader className="pb-3">
                 <div className="flex items-start justify-between">
                   <CardTitle className="text-lg">{habit.name}</CardTitle>
-                  {getHabitIcon(habit.type)}
+                  <div className="flex items-center gap-2">
+                    {getHabitIcon(habit.type)}
+                    <Button
+                      variant="ghost"
+                      size="icon"
+                      className="h-8 w-8 opacity-0 transition-opacity group-hover:opacity-100 hover:bg-black/20"
+                      onClick={(e) => openEditDialog(e, habit)}
+                    >
+                      <MoreVertical className="h-4 w-4" />
+                    </Button>
+                  </div>
                 </div>
               </CardHeader>
               <CardContent>
                 <div className="space-y-3">
                   {/* Last logged */}
-                  <div className="flex items-center gap-2 text-sm">
-                    <Clock className="h-4 w-4 text-zinc-500" />
-                    <span className="text-zinc-400">
-                      {habit.lastLoggedAt
-                        ? formatDistanceToNow(new Date(habit.lastLoggedAt), { addSuffix: true })
-                        : 'Never logged'}
-                    </span>
+                  <div className="flex items-center justify-between text-sm">
+                    <div className="flex items-center gap-2">
+                        <Clock className="h-4 w-4 text-zinc-500" />
+                        <span className="text-zinc-400">
+                        {habit.lastLoggedAt
+                            ? formatDistanceToNow(new Date(habit.lastLoggedAt), { addSuffix: true })
+                            : 'Never logged'}
+                        </span>
+                    </div>
+                    {habit.lastLoggedAt && (
+                        <TooltipProvider>
+                            <Tooltip>
+                                <TooltipTrigger asChild>
+                                    <Button
+                                        variant="ghost"
+                                        size="icon"
+                                        className="h-6 w-6 text-zinc-500 hover:text-red-400 hover:bg-red-950/30"
+                                        onClick={(e) => {
+                                            e.stopPropagation();
+                                            undoLogMutation.mutate(habit.id);
+                                        }}
+                                    >
+                                        <RotateCcw className="h-3 w-3" />
+                                    </Button>
+                                </TooltipTrigger>
+                                <TooltipContent>
+                                    <p>Undo last log</p>
+                                </TooltipContent>
+                            </Tooltip>
+                        </TooltipProvider>
+                    )}
                   </div>
 
                   <Separator className="bg-zinc-800" />
@@ -439,6 +552,105 @@ export default function Dashboard() {
             </Card>
           )}
         </div>
+        
+        {/* Edit Habit Dialog */}
+        <Dialog open={!!editingHabit} onOpenChange={(open) => !open && setEditingHabit(null)}>
+          <DialogContent className="border-zinc-800 bg-zinc-950">
+            <DialogHeader>
+              <DialogTitle>Edit Habit</DialogTitle>
+              <DialogDescription>
+                Modify your habit details or archive it if you no longer want to track it.
+              </DialogDescription>
+            </DialogHeader>
+            <div className="grid gap-4 py-4">
+              <div className="grid gap-2">
+                <Label htmlFor="edit-name">Habit Name</Label>
+                <Input
+                  id="edit-name"
+                  value={editHabitName}
+                  onChange={(e) => setEditHabitName(e.target.value)}
+                  className="border-zinc-800 bg-zinc-900"
+                />
+              </div>
+              <div className="grid gap-2">
+                <Label htmlFor="edit-type">Habit Type</Label>
+                <Select
+                  value={editHabitType}
+                  onValueChange={(value: 'positive' | 'neutral' | 'negative') => {
+                    setEditHabitType(value);
+                  }}
+                >
+                  <SelectTrigger className="border-zinc-800 bg-zinc-900">
+                    <SelectValue />
+                  </SelectTrigger>
+                  <SelectContent className="border-zinc-800 bg-zinc-900">
+                    <SelectItem value="positive">
+                      <div className="flex items-center gap-2">
+                        <TrendingUp className="h-4 w-4 text-emerald-500" />
+                        <span>Positive - Something to do more</span>
+                      </div>
+                    </SelectItem>
+                    <SelectItem value="neutral">
+                      <div className="flex items-center gap-2">
+                        <Activity className="h-4 w-4 text-zinc-500" />
+                        <span>Neutral - Just tracking</span>
+                      </div>
+                    </SelectItem>
+                    <SelectItem value="negative">
+                      <div className="flex items-center gap-2">
+                        <TrendingDown className="h-4 w-4 text-red-500" />
+                        <span>Negative - Something to reduce</span>
+                      </div>
+                    </SelectItem>
+                  </SelectContent>
+                </Select>
+              </div>
+            </div>
+            <DialogFooter className="flex-col items-stretch gap-2 sm:flex-row sm:justify-between">
+               <div className="flex flex-1 justify-start">
+                {showDeleteConfirm ? (
+                   <div className="flex items-center gap-2">
+                     <Button
+                       variant="destructive"
+                       onClick={handleDeleteHabit}
+                       disabled={deleteHabitMutation.isPending}
+                     >
+                       {deleteHabitMutation.isPending ? 'Deleting...' : 'Confirm Delete'}
+                     </Button>
+                     <Button variant="ghost" onClick={() => setShowDeleteConfirm(false)}>
+                       Cancel
+                     </Button>
+                   </div>
+                ) : (
+                  <Button
+                    variant="outline"
+                    className="border-red-900 text-red-500 hover:bg-red-950 hover:text-red-400"
+                    onClick={() => setShowDeleteConfirm(true)}
+                  >
+                    <Trash2 className="mr-2 h-4 w-4" />
+                    Archive Habit
+                  </Button>
+                )}
+               </div>
+               <div className="flex items-center gap-2 justify-end">
+                  <Button
+                    variant="outline"
+                    onClick={() => setEditingHabit(null)}
+                  >
+                    Cancel
+                  </Button>
+                  <Button
+                    onClick={handleUpdateHabit}
+                    disabled={!editHabitName.trim() || updateHabitMutation.isPending}
+                    className="bg-emerald-600 hover:bg-emerald-700"
+                  >
+                    <Save className="mr-2 h-4 w-4" />
+                    {updateHabitMutation.isPending ? 'Saving...' : 'Save Changes'}
+                  </Button>
+               </div>
+            </DialogFooter>
+          </DialogContent>
+        </Dialog>
       </div>
     </div>
   );