using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace SalesTaxes
{
public class TestCaseResult
{
public decimal Taxes { get; set; } //税合计
public decimal TotalPrice { get; set; } //总计含税
public TestCaseResult(decimal Taxes, decimal TotalPrice)
{
this.Taxes = Taxes;
this.TotalPrice = TotalPrice;
}
}
public class Test
{
//Test case1
public TestCaseResult GetResultForCasee1()
{
List<Goods> goods = new List<Goods>(); //第一批物品
goods.Add(new Goods("book", 1, false, (int)Enum_GoodType.Book, 12.49m));
goods.Add(new Goods("music CD", 1, false, (int)Enum_GoodType.Other, 14.99m));
goods.Add(new Goods("chocolcate bar", 1, false, (int)Enum_GoodType.Food, 0.85m));
return GetTestResult(goods);
}
public TestCaseResult GetResultForCasee2()
{
List<Goods> goods = new List<Goods>(); //第二批物品
goods.Add(new Goods("book", 1, true, (int)Enum_GoodType.Book, 10.0m));
goods.Add(new Goods("perfume", 1, true, (int)Enum_GoodType.Other, 47.5m));
return GetTestResult(goods);
}
public TestCaseResult GetResultForCasee3()
{
List<Goods> goods = new List<Goods>(); //第三批物品
goods.Add(new Goods("perfume", 1, true, (int)Enum_GoodType.Other, 27.99m));
goods.Add(new Goods("perfume", 1, false, (int)Enum_GoodType.Other, 18.99m));
goods.Add(new Goods("headache pills", 1, false, (int)Enum_GoodType.Drug, 9.75m));
goods.Add(new Goods("chocolates", 1, true, (int)Enum_GoodType.Food, 11.25m));
return GetTestResult(goods);
}
/// <summary>
/// 获取测试结果
/// </summary>
/// <param name="goods"></param>
/// <returns></returns>
private TestCaseResult GetTestResult(List<Goods> goods)
{
decimal totalGoods = 0;         //总价不含税
decimal totalGoodsByTax = 0;    //总价含税
for (int i = 0; i < goods.Count; i++)
{
totalGoods += goods[i].Price * goods[i].Count;
totalGoodsByTax += Goods.GetGoodsPriceByTax(goods[i]);
}
return new TestCaseResult(totalGoodsByTax - totalGoods, totalGoodsByTax);
}
}
class Program
{
static void Main(string[] args)
{
//Test case 1
var test = new Test();
var result = test.GetResultForCasee1();
Assert.AreEqual(1.50m, result.Taxes);
Assert.AreEqual(29.83m, result.TotalPrice);
//Test case 2
result = test.GetResultForCasee2();
Assert.AreEqual(7.65m, result.Taxes);
Assert.AreEqual(65.15m, result.TotalPrice);
//Test case 3
result = test.GetResultForCasee3();
Assert.AreEqual(6.70m, result.Taxes);
Assert.AreEqual(74.68m, result.TotalPrice);
}
}
/// <summary>
/// 商品名称
/// </summary>
class Goods
{
/// <summary>
/// 构造函数，初始化商品名称
/// </summary>
public Goods(string Name, int Count, bool Import, int GoodsType, decimal Price)
{
this.Name = Name;
this.Count = Count;
this.Import = Import;
this.GoodsType = GoodsType;
this.Price = Price;
}
/// <summary>
/// 商品名称
/// </summary>
public string Name { set; get; }
/// <summary>
/// 商品数量
/// </summary>
public int Count { set; get; }
/// <summary>
/// 是否进口（true=>进口）
/// </summary>
public bool Import { set; get; }
/// <summary>
/// 商品类型 对应枚举 Enum_GoodType
/// </summary>
public int GoodsType { set; get; }
/// <summary>
/// 单价
/// </summary>
public decimal Price { set; get; }
/// <summary>
/// 基本税
/// </summary>
const decimal BasicDuty = 0.1m;
/// <summary>
/// 进口附加税
/// </summary>
const decimal ImportSurtax = 0.05m;
/// <summary>
/// 计算商品的价格
/// </summary>
/// <param name="goods">商品</param>
/// <returns>商品最终价格</returns>
public static decimal GetGoodsPriceByTax(Goods goods)
{
decimal result = 0;
if (null != goods)
{
if (goods.Import)
{ //进口物品，添加附加税
decimal appTax = goods.Price * goods.Count * ImportSurtax;
result += GetMathResult(appTax);
}
if (goods.GoodsType == 4)
{//不是书籍、食品、药品 需要征收基础税，上面也可以写成(goods.GoodsType==(int)Enum_GoodType.Book ||...)
decimal baseTax = goods.Price * goods.Count * BasicDuty;
result += GetMathResult(baseTax);
}
result += goods.Price * goods.Count;
}
return result;
}
/// <summary>
/// 计算0.05舍弃值，核心代码
/// </summary>
/// <returns></returns>
private static decimal GetMathResult(decimal tax)
{
if ((tax / 0.05m).ToString().IndexOf(".") != -1)
{ //rounded up to the nearest 0.05
tax = Math.Round(tax, 1, MidpointRounding.AwayFromZero);
}
return tax;
}
}
/// <summary>
/// 商品类型
/// 备注：书籍、食品、药品 可分为一个枚举就是免基本税的，这样细分，考虑后期扩展
/// </summary>
enum Enum_GoodType
{
Book = 1,   //书籍
Food = 2,   //食品
Drug = 3,   //药品
Other = 4   //其他
    }
}