# Phase 7B: Pricing - COMPLETE ✅

## Completion Date
December 16, 2024

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## Overview

Phase 7B implements comprehensive pricing management with price lists, product prices, effective dates, quantity-based pricing, and customer-specific pricing.

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## ✅ Completed Deliverables

### 1. Price List Service (`modules/pricing/services/priceLists.js`)
- ✅ `createPriceList()` - Create price list with default flag management
- ✅ `getPriceList()` - Get price list by ID
- ✅ `updatePriceList()` - Update price list with validation
- ✅ `deletePriceList()` - Delete price list (validates no product prices or customers)
- ✅ `listPriceLists()` - List price lists with filters and pagination
- ✅ `getDefaultPriceList()` - Get default price list

### 2. Product Price Service (`modules/pricing/services/productPrices.js`)
- ✅ `createProductPrice()` - Create product price with overlapping detection
- ✅ `getProductPrice()` - Get product price by ID
- ✅ `updateProductPrice()` - Update product price with validation
- ✅ `deleteProductPrice()` - Delete product price
- ✅ `listProductPrices()` - List product prices with filters and pagination
- ✅ `getPrice()` - Get price for product/variant in price list
- ✅ `getPriceForCustomer()` - Get price for customer (uses customer's price list)

### 3. Pricing Controllers (`modules/pricing/controllers/index.js`)
- ✅ Price list controllers (create, get, update, delete, list, getDefault)
- ✅ Product price controllers (create, get, update, delete, list, lookup, customer)
- ✅ All endpoints with proper error handling
- ✅ System logging integration

### 4. Pricing Validations (`modules/pricing/validations/index.js`)
- ✅ Price list validations (create, update, get, delete, list)
- ✅ Product price validations (create, update, get, delete, list, lookup, customer)
- ✅ Request body validation
- ✅ Query parameter validation
- ✅ Date validation (ISO 8601)

### 5. Pricing Routes (`modules/pricing/routes/index.js`)
- ✅ RESTful endpoints with Swagger documentation
- ✅ All routes integrated into main routes
- ✅ Authentication required
- ✅ Role-based access control (manager, system_admin for write operations)

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## 📡 API Endpoints

### Price Lists

#### Create Price List
- **Endpoint:** `POST /api/pricing/price-lists`
- **Auth:** Required (manager, system_admin)
- **Body:**
  ```json
  {
    "name": "Retail Price List",
    "code": "RETAIL",
    "price_list_type": "RETAIL",
    "currency": "KES",
    "description": "Retail pricing",
    "is_default": true
  }
  ```
- **Returns:** Created price list

#### Get Price List by ID
- **Endpoint:** `GET /api/pricing/price-lists/:id`
- **Auth:** Required
- **Returns:** Price list details

#### Update Price List
- **Endpoint:** `PUT /api/pricing/price-lists/:id`
- **Auth:** Required (manager, system_admin)
- **Body:** Same as create (all fields optional)
- **Returns:** Updated price list

#### Delete Price List
- **Endpoint:** `DELETE /api/pricing/price-lists/:id`
- **Auth:** Required (manager, system_admin)
- **Returns:** Success message
- **Note:** Cannot delete if has product prices or customers

#### List Price Lists
- **Endpoint:** `GET /api/pricing/price-lists?page=1&limit=10&price_list_type=RETAIL&active=true`
- **Auth:** Required
- **Filters:**
  - `price_list_type` - Filter by type (RETAIL, WHOLESALE, B2B, CUSTOMER_SPECIFIC)
  - `active` - Filter by active status
- **Returns:** Paginated price lists list

#### Get Default Price List
- **Endpoint:** `GET /api/pricing/price-lists/default`
- **Auth:** Required
- **Returns:** Default price list

### Product Prices

#### Create Product Price
- **Endpoint:** `POST /api/pricing/prices`
- **Auth:** Required (manager, system_admin)
- **Body:**
  ```json
  {
    "price_list_id": 1,
    "product_id": 1,
    "variant_id": null,
    "price": 100.50,
    "min_quantity": 1,
    "max_quantity": null,
    "effective_from": "2024-01-01T00:00:00Z",
    "effective_to": null,
    "active": true
  }
  ```
- **Returns:** Created product price

#### Get Product Price by ID
- **Endpoint:** `GET /api/pricing/prices/:id`
- **Auth:** Required
- **Returns:** Product price details

#### Update Product Price
- **Endpoint:** `PUT /api/pricing/prices/:id`
- **Auth:** Required (manager, system_admin)
- **Body:** Same as create (all fields optional)
- **Returns:** Updated product price

#### Delete Product Price
- **Endpoint:** `DELETE /api/pricing/prices/:id`
- **Auth:** Required (manager, system_admin)
- **Returns:** Success message

#### List Product Prices
- **Endpoint:** `GET /api/pricing/prices?page=1&limit=10&price_list_id=1&product_id=1&variant_id=null&active=true`
- **Auth:** Required
- **Filters:**
  - `price_list_id` - Filter by price list ID
  - `product_id` - Filter by product ID
  - `variant_id` - Filter by variant ID (use 'null' for product-level prices)
  - `active` - Filter by active status
- **Returns:** Paginated product prices list (only shows currently effective prices)

#### Get Price Lookup
- **Endpoint:** `GET /api/pricing/prices/lookup?product_id=1&variant_id=null&quantity=1&price_list_id=1`
- **Auth:** Required
- **Query Parameters:**
  - `product_id` - Product ID (required)
  - `variant_id` - Variant ID (optional)
  - `quantity` - Quantity for quantity-based pricing (default: 1)
  - `price_list_id` - Price list ID (optional, uses default if not provided)
- **Returns:** Applicable product price

#### Get Price for Customer
- **Endpoint:** `GET /api/pricing/prices/customer?product_id=1&variant_id=null&quantity=1&customer_id=1`
- **Auth:** Required
- **Query Parameters:**
  - `product_id` - Product ID (required)
  - `variant_id` - Variant ID (optional)
  - `quantity` - Quantity for quantity-based pricing (default: 1)
  - `customer_id` - Customer ID (optional, uses customer's price list if provided)
- **Returns:** Applicable product price for customer

---

## 🔑 Key Features

### Price Lists
- **Multiple price lists** (Retail, Wholesale, B2B, Customer-Specific)
- **Default price list** designation
- **Currency support** (default: KES)
- **Active/inactive** status

### Product Prices
- **Product-level and variant-level** pricing
- **Quantity-based pricing** (min/max quantity tiers)
- **Effective date ranges** (effective_from, effective_to)
- **Price lookup logic** (customer price list → variant price → product price)
- **Quantity tier matching** (highest applicable tier)

### Price Lookup Logic
1. **Customer Price List:** If customer has assigned price list, use it
2. **Default Price List:** If no customer price list, use default
3. **Variant Price:** Prefer variant-specific price over product-level price
4. **Quantity Tier:** Match highest applicable quantity tier
5. **Effective Dates:** Only return prices effective now

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## 📊 Database Schema

### PriceList Table
- `id` - Primary key
- `name` - Price list name (required)
- `code` - Price list code (unique, required)
- `price_list_type` - Type (RETAIL, WHOLESALE, B2B, CUSTOMER_SPECIFIC)
- `currency` - Currency code (default: KES)
- `is_default` - Default flag
- `active` - Active status
- `description` - Description (optional)

### ProductPrice Table
- `id` - Primary key
- `price_list_id` - Foreign key to price_lists
- `product_id` - Foreign key to products
- `variant_id` - Foreign key to product_variants (optional)
- `price` - Unit price (required)
- `min_quantity` - Minimum quantity (default: 1)
- `max_quantity` - Maximum quantity (null for no limit)
- `effective_from` - Effective start date (default: now)
- `effective_to` - Effective end date (null for ongoing)
- `active` - Active status

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## 📝 Business Rules

1. **Price List Creation:**
   - Code must be unique
   - Only one default price list at a time
   - Setting new default unsets previous default

2. **Price List Deletion:**
   - Cannot delete if has product prices
   - Cannot delete if has assigned customers

3. **Product Price Creation:**
   - Price cannot be negative
   - Max quantity must be >= min quantity
   - Effective to date must be after effective from date
   - Overlapping prices allowed (warning logged)

4. **Price Lookup:**
   - Prefers variant-specific prices over product-level prices
   - Matches highest applicable quantity tier
   - Only returns prices effective now
   - Falls back to default price list if customer has no price list

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## ✅ Acceptance Criteria Met

- ✅ Price list CRUD operations working
- ✅ Product price CRUD operations working
- ✅ Effective date handling working
- ✅ Quantity-based pricing working
- ✅ Price lookup logic working
- ✅ Customer-specific pricing working
- ✅ Default price list management working

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## 🚀 Next Steps

Phase 7C: Taxes
- Implement tax rate service (CRUD)
- Implement tax category service
- Implement tax exemption service
- Create tax calculation service
- Integrate tax calculation into sale service

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**Phase 7B Status: COMPLETE ✅**

