# Product Discount Feature Implementation Summary

## Overview
Added discount functionality to the Products module, allowing users to set time-based discounts on products with specific date ranges.

## Changes Made

### 1. Database Schema (TAFDB.pgsql)
**Added `product_discounts` table:**
```sql
CREATE TABLE product_discounts (
  discount_id             uuid PRIMARY KEY DEFAULT uuid_generate_v7(),
  product_id              uuid REFERENCES products(product_id) ON DELETE CASCADE,
  discount_amount         NUMERIC(10,2) DEFAULT NULL,
  start_date              date DEFAULT NULL,
  end_date                date DEFAULT NULL,
  org_id                  uuid REFERENCES orgs(org_id) ON DELETE CASCADE,
  isDeleted               BOOLEAN NOT NULL DEFAULT FALSE,
  updatedAt               timestamptz NOT NULL DEFAULT now()
);
```

**Location:** After the `auto_orders` table definition (around line 421)

### 2. Form Definition (sql/defaults.sql)
**Added Product Discount Form (ID 134):**
- **Product (read-only)**: Display field showing the selected product name (pre-filled from row)
- **Product ID (hidden)**: Hidden field storing the product_id foreign key
- **Discount Amount**: Numeric input field for discount value
- **Start Date**: Date picker for discount start
- **End Date**: Date picker for discount end

**Features:**
- Product is pre-selected from the row action and displayed as read-only
- Product ID is stored in a hidden field for database mapping
- All form fields follow the existing form builder patterns
- Form maps to `product_discounts` table

**Location:** Added after Purchase Order form (ID 130), around line 3105

### 3. Products Module Update (sql/modules.sql)
**Updated Products module configuration:**
- Added `rowActions` array to the products table configuration
- Added "Discount" button with:
  - Label: "Discount"
  - Form ID: 134
  - Icon: "fa-tags"
  - Class: "btn-sm btn-info" (small info-colored button)

**Location:** Products module definition, around line 1300-1330

### 4. Table Registration (migrations/20251004_product_discounts.sql)
**Created migration file to ensure proper registration:**
- Registers `product_discounts` in `tenant_tables` for IndexedDB sync
- Includes column definitions for proper schema generation
- Uses INSERT with NOT EXISTS check to prevent duplicates

## User Flow

1. **Access Products Module**
   - User opens the Products module from the dashboard
   - Products table displays with all products

2. **Click Discount Button**
   - Each product row now has a "Discount" button in the actions column
   - Button appears next to the existing Edit and Delete buttons

3. **Fill Discount Form**
   - Form opens in a modal dialog
   - Product field is read-only, showing the selected product name
   - Product ID is automatically set from the row (hidden field)
   - User enters discount amount (numeric value)
   - User sets start date (date picker)
   - User sets end date (date picker)

4. **Save Discount**
   - Form validates required fields
   - Data saves to `product_discounts` table
   - Syncs via LocalSyncManager to IndexedDB
   - Modal closes automatically

## Technical Architecture

### Following AGENTS.md Guidelines:
✅ **MVC Pattern**: Uses existing model/controller infrastructure
✅ **Module Platform**: Leverages ModalBuilder and FormRenderer
✅ **Sync Platform**: Data syncs through LocalSyncManager and `/api/sync`
✅ **No Custom Controllers**: Uses generic sync endpoints
✅ **DaisyUI Components**: Button and form styling follow DaisyUI patterns
✅ **Database Standards**: Follows PostgreSQL naming and UUID conventions

### Form Field Types:
- Type 1: Text input with readonly attribute (for product name display)
- Type 1: Hidden text input (for product_id storage)
- Type 2: Numeric input (for discount amount)
- Type 3: Date picker (for start/end dates)

### Sync Behavior:
- `product_discounts` table registered in `tenant_tables`
- Automatically available in IndexedDB via `api/schema.php`
- Syncs through `/api/sync` generic endpoints
- No manual controller needed

## Deployment Steps

1. **Apply Database Changes:**
   ```bash
   psql -d TAFDB -f TAFDB.pgsql
   ```

2. **Run Migration:**
   ```bash
   psql -d TAFDB -f migrations/20251004_product_discounts.sql
   ```

3. **Apply Default Data:**
   ```bash
   psql -d TAFDB -f sql/defaults.sql
   ```

4. **Update Modules:**
   ```bash
   psql -d TAFDB -f sql/modules.sql
   ```

5. **Clear Cache & Test:**
   ```bash
   # Clear APCu cache if applicable
   php clear-apcu.php
   
   # Test the functionality
   ./test_setup.sh
   phpunit -c api/phpunit.xml
   npm test
   ```

## Testing Checklist

- [ ] Database table created successfully
- [ ] Product Discount form appears in forms table
- [ ] Products module loads without errors
- [ ] Discount button appears in products table actions
- [ ] Clicking Discount button opens the form modal
- [ ] Product field displays the selected product name (read-only)
- [ ] Product ID is correctly set in hidden field
- [ ] Form fields validate correctly (required fields)
- [ ] Discount saves successfully to database
- [ ] Data appears in product_discounts table
- [ ] Data syncs to IndexedDB
- [ ] Multiple discounts can be added for different products
- [ ] Date validation works (end date after start date)
- [ ] Discount can be edited after creation
- [ ] Discount can be deleted (soft delete)

## Future Enhancements (Optional)

- Display active discounts on product listing
- Automatic discount application in POS module
- Discount history/audit trail
- Bulk discount creation
- Discount templates
- Product details view showing discount info
- Read-only fields showing selected product name, price, brand

## Files Modified

1. `/var/www/html/TAF/TAFDB.pgsql` - Added product_discounts table
2. `/var/www/html/TAF/sql/defaults.sql` - Added Product Discount form (ID 134)
3. `/var/www/html/TAF/sql/modules.sql` - Updated Products module with Discount button
4. `/var/www/html/TAF/migrations/20251004_product_discounts.sql` - Migration script

## Notes

- The implementation is kept simple as requested - no extra modules
- All functionality integrated into existing Products module
- Uses established patterns from the codebase
- No custom JavaScript needed - all handled by existing infrastructure
- Form automatically handles product selection and discount data
- Date range validation can be added at application level if needed