johngummadi / planmart

PlanMart

For this homework we are creating the next great online shopping super store PlanMart! We need you to implement the order processing and validation system. You are provided with a set of classes representing an Order and are expected to create an implementation of the interface IOrderProcessor (C#) or OrderProcessor (Java). This interface simply defines one method:

C#

bool ProcessOrder(Order order);

Java

boolean processOrder(Order order);

What We're Looking For

Ideally when you're done you have something that works, and the code is designed in a fashion you'd be proud to show to others. Also, when contemplating your design, allow that there may be future implementations of the interface for different companies and that the requirements between those implementations may have a lot of similarities. The nature of the specification outlined below is intended to be more than you could complete in a short time but exists to illustrate the sort of challenges your design should be prepared to accomodate. We'd rather see elegant code that implements only a small portion of the specification than poorly-designed code that implements it all. Quality over quantity.

Context

Imagine you are at the standard stage of an online ordering process where you click "checkout" and are taken to a confirmation screen that summarizes the products in your cart, shipping costs, taxes, etc. This page would typically have a button, "Buy Now", which would execute the order. This method represents the work needed to create this confirmation page.

You are expected to perform two tasks in this method:

• Return true or false depending on whether the order is valid
• Add zero or more line items to the order representing details such as taxes, shipping costs, and reward points.

Set aside about two hours to work on this. It is not a problem if you don't have enough time to implement every nuance.

Specification

Here are the rules the implementation must enforce (feel free to implement any subset of these in the allocated time):

• All items are taxed at 8% unless exempt
• The following types of items are exempt from tax:
  • Food items shipped to CA, NY
  • Clothing items shipped to CT
• Orders to nonprofits are exempt from all tax and shipping
• Orders get 1 reward point per $2 spent
• Orders get double rewards points when:
  • Using PlanMart rewards credit card
  • Three of these criteria met:
    • Multiple different products in the same order
    • Orders over $200 shipped to US regions other than AZ
    • Orders over $100 shipped to AZ
    • Orders on:
      • Any of the 3 recurring Black Fridays
      • Memorial Day
      • Veteran’s Day
• Alcohol may not be shipped to VA, NC, SC, TN, AK, KY, AL
• Alcohol may only be shipped to customers age 21 or over in the US
• Shipping is $10 for orders under 20 pounds in the continental US
• Shipping is $20 for orders 20 pounds or over in the continental US
• Shipping for orders to the non-continental US is $35
• Food may not be shipped to HI
• An Order should not be empty (the customer should be ordering something!)
• Sales tax should be rounded using the round half up strategy

Data Model

We provide the following types:

• Order - The parameter to the processor and the top level object with which you interact. Contains various details such as the products ordered, the shipping address, line items, etc.
• Customer - Details about the customer who placed the order, including the date of birth, and whether they are a non-profit.
• Product - Describes a single product (such as a book, a TV, etc.) with details that describe the product such as its weight and price.
• ProductType - An enum that specifies what sort of product it is (alcohol, clothing, etc.)
• PaymentMethod - An enum that specifies what payment method the customer used (Visa, PlanMart Rewards Card, etc.)
• LineItem - Added to an Order by the processor to indicate taxes, shipping costs, and awarded reward points.
• LineItemType - An enum that specifies whether the line item represents taxes, shipping costs, etc.
• ProductOrder - An Order contains one of these that describes what product is being ordered and how many..

Example

Order
	ShippingRegion: AZ
	PaymentMethod: Visa
	Placed: 2015-11-27
	Items: 
		ProductOrder
			Product
				Type: Alcohol
				Price: $20
				Weight: 2 lb
			Quantity: 3
		ProductOrder
			Product
				Type: Food
				Price: $25
				Weight: 3 lb
			Quantity: 3
	Customer
		BirthDate: 1988-03-04
		IsNonProfit: false

The processor should return true:

• While alcohol is involved, the customer is over the age of 21
• The order is not being shipped to any of VA, NC, SC, TN, AK, KY, or AL

The processor should add the following line items to the order:

Order
	LineItems
		LineItem
			Type: Tax
			Amount: $10.80
		LineItem
			Type: Shipping
			Amount: $10.00
		LineItem
			Type: RewardsPoints
			Amount: 134

• A tax of $10.80 is 8% of the order total of $135
• The total weight of the order is less than 20 lb so shipping is $10
• $135 was spent, which represent 67 $2 chunks, giving us 67 reward points as a base. But the amount is doubled to 134 because:
  • The order was shipped to Arizona and the order total was greater than $100
  • More than one each of two different products were ordered
  • The order was placed on the day after Thanksgiving (a Black Friday)

Unit Tests

In addition to implementing the processor interface, you should also write unit tests that verify that your processor is producing the results expected of the specification. Each unit test should instantiate and populate an Order and call your implementation and validate the results.