Add timer functionality to track time spent on tasks

Introduces a `useTimer` hook to manage starting and stopping timers for tasks, updating their `timeTracked` property, and displaying tracking status. This involves changes in `App.tsx`, `KanbanBoard.tsx`, `TaskCard.tsx`, and `TasksWithCalendar.tsx` to integrate the timer start/stop actions and display.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ceced2fc-aa46-458d-ba87-ddd4b7bb1518
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/659922a9-0087-461c-90dd-6d9a58b81d4d/ceced2fc-aa46-458d-ba87-ddd4b7bb1518/P2PZNJ9

client/src/hooks/useTimer.ts

@@ -0,0 +1,113 @@
+import { useEffect, useRef } from 'react';
+import { Task } from '@shared/schema';
+
+interface UseTimerProps {
+  tasks: Task[];
+  onTaskUpdate: (taskId: string, updates: Partial<Task>) => void;
+}
+
+export function useTimer({ tasks, onTaskUpdate }: UseTimerProps) {
+  const intervalRef = useRef<NodeJS.Timeout | null>(null);
+  const lastUpdateRef = useRef<{ [taskId: string]: number }>({});
+
+  useEffect(() => {
+    // Find tasks that are currently being tracked
+    const trackingTasks = tasks.filter(task => task.isTracking);
+    
+    if (trackingTasks.length > 0) {
+      // Start the timer
+      intervalRef.current = setInterval(() => {
+        const now = Date.now();
+        
+        trackingTasks.forEach(task => {
+          // Initialize last update time if not set
+          if (!lastUpdateRef.current[task.id]) {
+            lastUpdateRef.current[task.id] = now;
+            return;
+          }
+          
+          // Calculate elapsed time since last update (in minutes)
+          const elapsed = (now - lastUpdateRef.current[task.id]) / 1000 / 60;
+          
+          // Only update if at least 1 minute has passed (to avoid too frequent updates)
+          if (elapsed >= 1) {
+            const currentTime = task.timeTracked || 0;
+            const newTime = currentTime + Math.floor(elapsed);
+            
+            onTaskUpdate(task.id, { timeTracked: newTime });
+            lastUpdateRef.current[task.id] = now;
+            
+            console.log(`Timer updated for "${task.title}": +${Math.floor(elapsed)}min (total: ${newTime}min)`);
+          }
+        });
+      }, 60000); // Update every minute
+    } else {
+      // No tasks are being tracked, clear the timer
+      if (intervalRef.current) {
+        clearInterval(intervalRef.current);
+        intervalRef.current = null;
+      }
+      // Clear last update times for stopped tasks
+      lastUpdateRef.current = {};
+    }
+
+    // Cleanup on unmount or when tracking tasks change
+    return () => {
+      if (intervalRef.current) {
+        clearInterval(intervalRef.current);
+        intervalRef.current = null;
+      }
+    };
+  }, [tasks.map(t => `${t.id}:${t.isTracking}`).join(','), onTaskUpdate]);
+
+  // Initialize last update times for currently tracking tasks
+  useEffect(() => {
+    const now = Date.now();
+    tasks.forEach(task => {
+      if (task.isTracking && !lastUpdateRef.current[task.id]) {
+        lastUpdateRef.current[task.id] = now;
+      } else if (!task.isTracking && lastUpdateRef.current[task.id]) {
+        delete lastUpdateRef.current[task.id];
+      }
+    });
+  }, [tasks]);
+
+  const startTimer = (taskId: string) => {
+    const now = Date.now();
+    lastUpdateRef.current[taskId] = now;
+    onTaskUpdate(taskId, { isTracking: true });
+    console.log(`Timer started for task: ${taskId}`);
+  };
+
+  const stopTimer = (taskId: string) => {
+    const task = tasks.find(t => t.id === taskId);
+    if (task && lastUpdateRef.current[taskId]) {
+      const now = Date.now();
+      const elapsed = (now - lastUpdateRef.current[taskId]) / 1000 / 60;
+      
+      if (elapsed >= 0.1) { // Add time if at least 6 seconds have passed
+        const currentTime = task.timeTracked || 0;
+        const additionalTime = Math.max(1, Math.round(elapsed)); // At least 1 minute
+        const newTime = currentTime + additionalTime;
+        
+        onTaskUpdate(taskId, { 
+          isTracking: false, 
+          timeTracked: newTime 
+        });
+        
+        console.log(`Timer stopped for "${task.title}": +${additionalTime}min (total: ${newTime}min)`);
+      } else {
+        onTaskUpdate(taskId, { isTracking: false });
+      }
+      
+      delete lastUpdateRef.current[taskId];
+    } else {
+      onTaskUpdate(taskId, { isTracking: false });
+    }
+  };
+
+  return {
+    startTimer,
+    stopTimer
+  };
+}