adding today feature on main habit page, show streaks feature on settings page and improved dark mode functionality

src/hooks/useHabits.ts

@@ -0,0 +1,99 @@
+import { useState } from 'react';
+import { Habit } from '../types';
+
+export const useHabits = () => {
+  const [habits, setHabits] = useState<Habit[]>([]);
+
+  const fetchHabits = async () => {
+    try {
+      const response = await fetch('http://localhost:5000/api/habits');
+      const data = await response.json();
+      setHabits(data);
+    } catch (error) {
+      console.error('Error fetching habits:', error);
+      setHabits([]);
+    }
+  };
+
+  const addHabit = async (name: string) => {
+    try {
+      const response = await fetch('http://localhost:5000/api/habits', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ name }),
+      });
+      if (response.ok) {
+        await fetchHabits();
+        return true;
+      }
+      return false;
+    } catch (error) {
+      console.error('Error adding habit:', error);
+      return false;
+    }
+  };
+
+  const toggleHabit = async (id: number, date: string) => {
+    try {
+      await fetch(`http://localhost:5000/api/habits/${id}/toggle`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ date }),
+      });
+      await fetchHabits();
+    } catch (error) {
+      console.error('Error toggling habit:', error);
+    }
+  };
+
+  const updateHabit = async (id: number, name: string) => {
+    try {
+      await fetch(`http://localhost:5000/api/habits/${id}`, {
+        method: 'PUT',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ name }),
+      });
+      await fetchHabits();
+    } catch (error) {
+      console.error('Error updating habit:', error);
+    }
+  };
+
+  const deleteHabit = async (id: number) => {
+    try {
+      await fetch(`http://localhost:5000/api/habits/${id}`, {
+        method: 'DELETE',
+      });
+      await fetchHabits();
+    } catch (error) {
+      console.error('Error deleting habit:', error);
+    }
+  };
+
+  const updateStreak = async (id: number, newStreak: number) => {
+    if (newStreak < 0) return;
+
+    try {
+      await fetch(`http://localhost:5000/api/habits/${id}/streak`, {
+        method: 'PUT',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ streak: newStreak }),
+      });
+      setHabits(habits.map(habit =>
+        habit.id === id ? { ...habit, manualStreak: newStreak } : habit
+      ));
+    } catch (error) {
+      console.error('Error updating streak:', error);
+    }
+  };
+
+  return {
+    habits,
+    fetchHabits,
+    addHabit,
+    toggleHabit,
+    updateHabit,
+    deleteHabit,
+    updateStreak
+  };
+};