# ItemAutocomplete Component Implementation Summary

## Overview
Created a reusable autocomplete component for item search with debounced API calls, keyboard navigation, and visual feedback.

## Component Location
`web/app/components/ItemAutocomplete.tsx`

## Features Implemented

### ✅ Core Functionality
- **Debounced Search**: 300ms delay after typing before API call
- **Minimum Characters**: Requires 2+ characters before searching
- **API Integration**: Uses `searchItems` function from `@/lib/api`
- **Loading Indicator**: Animated spinner during API calls
- **Suggestions Dropdown**: Fixed positioning below input field

### ✅ User Interface
- **Item Display**: Item code (bold) and item name (secondary/muted)
- **No Results Message**: Shows "No results found" when search returns empty
- **Loading State**: Visual feedback with spinner and blue border
- **Disabled State**: Supports disabled prop with visual indication
- **Brand Colors**: Uses #4c6fff brand color for consistency

### ✅ Keyboard Navigation
- **Arrow Down**: Navigate to next suggestion
- **Arrow Up**: Navigate to previous suggestion
- **Enter**: Select highlighted suggestion
- **Escape**: Close dropdown

### ✅ Interaction
- **Click to Select**: Click any suggestion to select it
- **Click Outside**: Closes dropdown when clicking outside
- **Hover Highlight**: Visual feedback on mouse hover
- **Scroll Support**: Dropdown has max height (320px) with scroll

### ✅ Props Interface
```typescript
interface ItemAutocompleteProps {
  value: string;                    // Current input value
  onSelect: (item: ItemRecord) => void;  // Called when item selected
  onChange: (value: string) => void;     // Called on input change
  placeholder?: string;             // Optional placeholder text
  disabled?: boolean;               // Optional disabled state
}
```

## Testing

### Test Coverage
- ✅ 10/10 tests passing
- ✅ Renders with placeholder
- ✅ Calls onChange when typing
- ✅ Does not search with < 2 characters
- ✅ Displays suggestions after successful search
- ✅ Shows "No results found" message
- ✅ Calls onSelect when clicking suggestion
- ✅ Keyboard navigation (Arrow Down + Enter)
- ✅ Closes on Escape key
- ✅ Disabled state prevents search

### Test File
`web/app/components/ItemAutocomplete.test.tsx`

## Design Patterns

### Debouncing
- Uses `useRef` to store timer reference
- Clears previous timer on each keystroke
- Waits 300ms before triggering API call
- Cleanup function clears timer on unmount

### Dropdown Positioning
- Uses fixed positioning to avoid overflow issues
- Calculates position based on input element's `getBoundingClientRect()`
- Updates position when dropdown opens
- Accounts for window scroll offset

### Click Outside Detection
- Adds mousedown event listener when dropdown is open
- Checks if click target is outside both input and dropdown
- Removes listener when dropdown closes

### State Management
- `showSuggestions`: Controls dropdown visibility
- `suggestions`: Stores search results
- `selectedIndex`: Tracks keyboard navigation position
- `isLoading`: Shows loading indicator
- `dropdownPosition`: Stores calculated position

## Acceptance Criteria Met

✅ Component shows suggestions after typing 2+ characters  
✅ Debounce prevents excessive API calls (300ms delay)  
✅ Loading spinner shows during API call  
✅ Suggestions show item code (bold) and item name (muted)  
✅ Keyboard navigation works (arrows, Enter, Escape)  
✅ Clicking suggestion calls `onSelect` with full ItemRecord  
✅ Clicking outside closes dropdown  
✅ "No results" message appears when no matches  
✅ Matches existing visual design (brand colors #4c6fff, spacing)

## Next Steps

This component is ready to be integrated into:
1. **Stock-In Items Table** (`web/app/stock-in/ItemsTableNew.tsx`) - Task 5
2. **Stock-Out Items Table** (`web/app/stock-out/StockOutModal.tsx`) - Task 6

## Usage Example

```typescript
import ItemAutocomplete from "@/app/components/ItemAutocomplete";

function MyComponent() {
  const [itemCode, setItemCode] = useState("");

  function handleItemSelect(item: ItemRecord) {
    // Populate form fields with selected item
    setItemCode(item.itemCode);
    setItemName(item.itemName);
    // ... other fields
  }

  return (
    <ItemAutocomplete
      value={itemCode}
      onSelect={handleItemSelect}
      onChange={setItemCode}
      placeholder="Search by item code or name..."
      disabled={false}
    />
  );
}
```

## Performance Considerations

- **Debouncing**: Reduces API calls by waiting 300ms after last keystroke
- **Result Limit**: Backend limits results to 10 items (handled by API)
- **Efficient Re-renders**: Uses `useRef` for timer to avoid unnecessary re-renders
- **Cleanup**: Properly cleans up timers and event listeners

## Browser Compatibility

- Modern browsers (Chrome, Firefox, Safari, Edge)
- Uses standard React hooks and DOM APIs
- CSS animations for spinner (widely supported)
- Fixed positioning (widely supported)