Food Store Order Price Calculator

Description

This package provides functionality to calculate the total cost of an order. It takes into account item-specific discounts and an optional membership discount.

Structure

Item: Defines properties of a purchasable item. Includes the name, base price, and any discount.

OrderItems: A map that connects item names to their respective quantities in an order.

Calculator: Can be used to calculate the price of an order.

Usage

order := OrderItems{
  	"Red":    2,
  	"Green":  3,
  	"Pink":   1
  	"Orange": 2,
}

// Create a new Calculator
calculator := &Calculator{}

// Calculate the price for a non-member and then for a member
nonMemberPrice, err := calculator.CalculatePrice(order, false)
memberPrice, err := calculator.CalculatePrice(order, true)

Examples

1: Basic order without member card

	order1 := OrderItems{
		"Red":     2,
		"Green":   3,
		"Purple":  1,
	}
	price1, err := calculator.CalculatePrice(order1, false)
	if err != nil {
		fmt.Printf("Error calculating price: %s\n", err)
	} else {
		fmt.Printf("Total price for order 1: %.2f\n", price1)
	}

2: Order with member card and item discounts

	order2 := OrderItems{
		"Green":   3,  // This will get an item discount
		"Pink":    2,  // This will get an item discount
		"Orange":  1,
	}
	price2, err := calculator.CalculatePrice(order2, true) // Note the member card flag set to true
	if err != nil {
		fmt.Printf("Error calculating price: %s\n", err)
	} else {
		fmt.Printf("Total price for order 2 (with member card): %.2f\n", price2)
	}

3: Order with a non-existent item

	order3 := OrderItems{
		"Green":    2,
		"Magenta":  3,  // This item doesn't exist in the itemsMap
	}
	price3, err := calculator.CalculatePrice(order3, false)
	if err != nil {
		fmt.Printf("Error calculating price: %s\n", err)
	} else {
		fmt.Printf("Total price for order 3: %.2f\n", price3)
	}

Spec

This food store only have 7 items in menu:
- Red set 50 THB/set.
- Green set 40 THB/set.
- Blue set 30 THB/set.
- Yellow set 50 THB/set.
- Pink set 80 THB/set.
- Purple set 90 THB/set.
- Orange set 120 THB/set.
Customers can order multiple items.
Write a function that receives these 7 items, calculate and return price.
Conditions:
- Customers can get 10% if customers have a member card.
- Order doubles of Orange, Pink or Green sets will get a 5% discount.
If you provide unit-tests; you will get an extra score.
Example:
- Desk#1: Customers order Red set and Green set; price from calculation is 90.
- Customers can use a 10% discount card, then price should be deducted by discount amount.
  - For Orange sets, if customers order more than 2 items per bill. customers will get a 5% discount.

zdk / food-store