Add unit preferences to user settings

src/hooks/useUnitPreferences.ts

@@ -0,0 +1,119 @@
+import { useState, useEffect } from 'react';
+import { useAuth } from '@/hooks/useAuth';
+import { supabase } from '@/integrations/supabase/client';
+import { UnitPreferences, getMeasurementSystemFromCountry } from '@/lib/units';
+
+const DEFAULT_PREFERENCES: UnitPreferences = {
+  measurement_system: 'metric',
+  temperature: 'celsius',
+  auto_detect: true
+};
+
+export function useUnitPreferences() {
+  const { user } = useAuth();
+  const [preferences, setPreferences] = useState<UnitPreferences>(DEFAULT_PREFERENCES);
+  const [loading, setLoading] = useState(true);
+
+  useEffect(() => {
+    loadPreferences();
+  }, [user]);
+
+  const loadPreferences = async () => {
+    try {
+      if (user) {
+        // Load from database for logged-in users
+        const { data } = await supabase
+          .from('user_preferences')
+          .select('unit_preferences')
+          .eq('user_id', user.id)
+          .maybeSingle();
+
+        if (data?.unit_preferences && typeof data.unit_preferences === 'object') {
+          setPreferences({ ...DEFAULT_PREFERENCES, ...(data.unit_preferences as unknown as UnitPreferences) });
+        } else {
+          // Auto-detect for new users
+          await autoDetectPreferences();
+        }
+      } else {
+        // Check localStorage for anonymous users
+        const stored = localStorage.getItem('unit_preferences');
+        if (stored) {
+          try {
+            const parsed = JSON.parse(stored);
+            setPreferences({ ...DEFAULT_PREFERENCES, ...parsed });
+          } catch (e) {
+            await autoDetectPreferences();
+          }
+        } else {
+          await autoDetectPreferences();
+        }
+      }
+    } catch (error) {
+      console.error('Error loading unit preferences:', error);
+      await autoDetectPreferences();
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  const autoDetectPreferences = async () => {
+    try {
+      const response = await supabase.functions.invoke('detect-location');
+      
+      if (response.data && response.data.measurementSystem) {
+        const newPreferences: UnitPreferences = {
+          ...DEFAULT_PREFERENCES,
+          measurement_system: response.data.measurementSystem,
+        };
+        
+        setPreferences(newPreferences);
+        
+        // Save to localStorage for anonymous users
+        if (!user) {
+          localStorage.setItem('unit_preferences', JSON.stringify(newPreferences));
+        }
+        
+        return newPreferences;
+      }
+    } catch (error) {
+      console.error('Error auto-detecting location:', error);
+    }
+    
+    // Fallback to default
+    setPreferences(DEFAULT_PREFERENCES);
+    return DEFAULT_PREFERENCES;
+  };
+
+  const updatePreferences = async (newPreferences: Partial<UnitPreferences>) => {
+    const updated = { ...preferences, ...newPreferences };
+    setPreferences(updated);
+
+    try {
+      if (user) {
+        // Save to database for logged-in users
+        await supabase
+          .from('user_preferences')
+          .update({ 
+            unit_preferences: updated,
+            updated_at: new Date().toISOString()
+          })
+          .eq('user_id', user.id);
+      } else {
+        // Save to localStorage for anonymous users
+        localStorage.setItem('unit_preferences', JSON.stringify(updated));
+      }
+    } catch (error) {
+      console.error('Error saving unit preferences:', error);
+      // Revert on error
+      setPreferences(preferences);
+      throw error;
+    }
+  };
+
+  return {
+    preferences,
+    loading,
+    updatePreferences,
+    autoDetectPreferences
+  };
+}