PT-1924: Add rounding policy (#189)

* PT-1924: Add rounding policy * PT-1924: Add unit tests * PT-1924: Set Round Policy in CurrencyService * PT-1924: Add RoundType and MidpointRounding properties to the blade * PT-1924: Fix deserialization issue Co-authored-by: Filipp Kuksov <[email protected]>
VirtoCommerce · Aug 5, 2021 · 55e7c24 · 55e7c24
1 parent 4ff78c9
commit 55e7c24
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Showing 16 changed files with 519 additions and 23 deletions.
diff --git a/src/VirtoCommerce.CoreModule.Core/Currency/Currency.cs b/src/VirtoCommerce.CoreModule.Core/Currency/Currency.cs
@@ -1,9 +1,11 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
-using System.Text.Json.Serialization;
+using Newtonsoft.Json;
 using VirtoCommerce.CoreModule.Core.Common;
 using VirtoCommerce.Platform.Core.Common;
+using MidpointRoundingEnum = System.MidpointRounding;
+using RoundingTypeEnum = VirtoCommerce.CoreModule.Core.Enums.RoundingType;
 
 namespace VirtoCommerce.CoreModule.Core.Currency
 {
@@ -60,10 +62,8 @@ public Currency(Language language, string code)
         public Currency()
             : this(Language.InvariantLanguage, null)
         {
-
         }
 
-
         /// <summary>
         /// Currency code may be used ISO 4217.
         /// </summary>
@@ -87,7 +87,6 @@ public string CultureName
             }
         }
 
-
         public string EnglishName { get; set; }
 
         [JsonIgnore]
@@ -97,14 +96,17 @@ public string CultureName
         ///  name of the currency
         /// </summary>
         public string Name { get; set; }
+
         /// <summary>
         /// Flag specifies that this is the primary currency
         /// </summary>
         public bool IsPrimary { get; set; }
+
         /// <summary>
         /// The exchange rate against the primary exchange rate of the currency.
         /// </summary>
         public decimal ExchangeRate { get; set; }
+
         /// <summary>
         /// Currency symbol
         /// </summary>
@@ -115,6 +117,24 @@ public string CultureName
         /// </summary>
         public string CustomFormatting { get; set; }
 
+        [JsonIgnore]
+        public IMoneyRoundingPolicy RoundingPolicy { get; set; }
+
+        private RoundingTypeEnum _roundingType = RoundingTypeEnum.Rounding001;
+
+        public string RoundingType
+        {
+            get { return _roundingType.ToString(); }
+            set { _roundingType = EnumUtility.SafeParse(value, RoundingTypeEnum.Rounding001); }
+        }
+
+        private MidpointRoundingEnum _midpointRounding = MidpointRoundingEnum.AwayFromZero;
+
+        public string MidpointRounding
+        {
+            get { return _midpointRounding.ToString(); }
+            set { _midpointRounding = EnumUtility.SafeParse(value, MidpointRoundingEnum.AwayFromZero); }
+        }
 
         protected override IEnumerable<object> GetEqualityComponents()
         {

diff --git a/src/VirtoCommerce.CoreModule.Core/Currency/DefaultMoneyRoundingPolicy.cs b/src/VirtoCommerce.CoreModule.Core/Currency/DefaultMoneyRoundingPolicy.cs
@@ -0,0 +1,92 @@
+using System;
+using VirtoCommerce.CoreModule.Core.Enums;
+using VirtoCommerce.Platform.Core.Common;
+
+namespace VirtoCommerce.CoreModule.Core.Currency
+{
+    // TODO: Reduce the cognitive complexity
+    // https://github.com/grandnode/grandnode2/blob/master/src/Business/Grand.Business.Catalog/Extensions/RoundingHelper.cs#L44
+    public class DefaultMoneyRoundingPolicy : IMoneyRoundingPolicy
+    {
+        public decimal RoundMoney(decimal amount, Currency currency)
+        {
+            var roundingType = EnumUtility.SafeParse(currency.RoundingType, RoundingType.Rounding001);
+            var midpointRounding = EnumUtility.SafeParse(currency.MidpointRounding, MidpointRounding.AwayFromZero);
+            return Round(amount, currency.NumberFormat.NumberDecimalDigits, roundingType, midpointRounding);
+        }
+
+        /// <summary>
+        /// Round
+        /// </summary>
+        /// <param name="value">Value to round</param>
+        /// <param name="decimals">Number of digits in fractional part</param>
+        /// <param name="roundingType">The rounding type</param>
+        /// <param name="midpointRounding">Specifies how mathematical rounding methods should process a number that is midway between two numbers</param>
+        /// <returns>Rounded value</returns>
+        protected decimal Round(decimal value, int decimals, RoundingType roundingType, MidpointRounding midpointRounding)
+        {
+            //default round (Rounding001)
+            var result = Math.Round(value, decimals, midpointRounding);
+            var fractionPart = (result - Math.Truncate(result)) * 10;
+
+            //cash rounding not needed
+            if (fractionPart == 0)
+                return result;
+
+            //Cash rounding (details: https://en.wikipedia.org/wiki/Cash_rounding)
+            switch (roundingType)
+            {
+                //rounding with 0.05 or 5 intervals
+                case RoundingType.Rounding005Up:
+                case RoundingType.Rounding005Down:
+                    fractionPart = (fractionPart - Math.Truncate(fractionPart)) * 10;
+                    if (fractionPart == 5 || fractionPart == 0)
+                        break;
+                    if (roundingType == RoundingType.Rounding005Down)
+                        fractionPart = fractionPart > 5 ? 5 - fractionPart : fractionPart * -1;
+                    else
+                        fractionPart = fractionPart > 5 ? 10 - fractionPart : 5 - fractionPart;
+
+                    result += fractionPart / 100;
+                    break;
+                //rounding with 0.10 intervals
+                case RoundingType.Rounding01Up:
+                case RoundingType.Rounding01Down:
+                    fractionPart = (fractionPart - Math.Truncate(fractionPart)) * 10;
+                    if (fractionPart == 0)
+                        break;
+
+                    if (roundingType == RoundingType.Rounding01Down && fractionPart == 5)
+                        fractionPart = -5;
+                    else
+                        fractionPart = fractionPart < 5 ? fractionPart * -1 : 10 - fractionPart;
+
+                    result += fractionPart / 100;
+                    break;
+                //rounding with 0.50 intervals
+                case RoundingType.Rounding05:
+                    fractionPart *= 10;
+                    fractionPart = fractionPart < 25 ? fractionPart * -1 : fractionPart < 50 || fractionPart < 75 ? 50 - fractionPart : 100 - fractionPart;
+
+                    result += fractionPart / 100;
+                    break;
+                //rounding with 1.00 intervals
+                case RoundingType.Rounding1:
+                case RoundingType.Rounding1Up:
+                    fractionPart *= 10;
+
+                    if (roundingType == RoundingType.Rounding1Up && fractionPart > 0)
+                        result = Math.Truncate(result) + 1;
+                    else
+                        result = fractionPart < 50 ? Math.Truncate(result) : Math.Truncate(result) + 1;
+
+                    break;
+                case RoundingType.Rounding001:
+                default:
+                    break;
+            }
+
+            return result;
+        }
+    }
+}
diff --git a/src/VirtoCommerce.CoreModule.Core/Currency/IMoneyRoundingPolicy.cs b/src/VirtoCommerce.CoreModule.Core/Currency/IMoneyRoundingPolicy.cs
@@ -0,0 +1,7 @@
+namespace VirtoCommerce.CoreModule.Core.Currency
+{
+    public interface IMoneyRoundingPolicy
+    {
+        decimal RoundMoney(decimal amount, Currency currency);
+    }
+}
diff --git a/src/VirtoCommerce.CoreModule.Core/Currency/Money.cs b/src/VirtoCommerce.CoreModule.Core/Currency/Money.cs
@@ -32,7 +32,7 @@ public Money(decimal amount, Currency currency)
         /// of the associated currency using MidpointRounding.AwayFromZero.
         /// </summary>
         /// <returns>A decimal with the amount rounded to the significant number of decimal digits.</returns>
-        public decimal Amount => decimal.Round(InternalAmount, DecimalDigits, MidpointRounding.AwayFromZero);
+        public decimal Amount => Currency.RoundingPolicy.RoundMoney(InternalAmount, Currency);
 
         /// <summary>
         /// Truncates the amount to the number of significant decimal digits

diff --git a/src/VirtoCommerce.CoreModule.Core/Enums/RoundingType.cs b/src/VirtoCommerce.CoreModule.Core/Enums/RoundingType.cs
@@ -0,0 +1,15 @@
+namespace VirtoCommerce.CoreModule.Core.Enums
+{
+    //Cash rounding (details: https://en.wikipedia.org/wiki/Cash_rounding)
+    public enum RoundingType
+    {
+        Rounding001,
+        Rounding005Up,
+        Rounding005Down,
+        Rounding01Up,
+        Rounding01Down,
+        Rounding05,
+        Rounding1,
+        Rounding1Up
+    }
+}
diff --git a/src/VirtoCommerce.CoreModule.Data/Currency/CurrencyEntity.cs b/src/VirtoCommerce.CoreModule.Data/Currency/CurrencyEntity.cs
@@ -24,6 +24,10 @@ public class CurrencyEntity : AuditableEntity
 
         [StringLength(64)]
         public string CustomFormatting { get; set; }
+        [StringLength(16)]
+        public string MidpointRounding { get; set; }
+        [StringLength(16)]
+        public string RoundingType { get; set; }
 
         public virtual Core.Currency.Currency ToModel(Core.Currency.Currency currency)
         {
@@ -33,6 +37,8 @@ public virtual Core.Currency.Currency ToModel(Core.Currency.Currency currency)
             currency.ExchangeRate = ExchangeRate;
             currency.Symbol = Symbol;
             currency.CustomFormatting = CustomFormatting;
+            currency.MidpointRounding = MidpointRounding;
+            currency.RoundingType = RoundingType;
             return currency;
         }
 
@@ -44,17 +50,21 @@ public virtual CurrencyEntity FromModel(Core.Currency.Currency currency)
             ExchangeRate = currency.ExchangeRate;
             Symbol = currency.Symbol;
             CustomFormatting = currency.CustomFormatting;
+            MidpointRounding = currency.MidpointRounding.ToString();
+            RoundingType = currency.RoundingType.ToString();
             return this;
         }
 
         public virtual void Patch(CurrencyEntity target)
         {
-            target.Code = Code;
+            target.Code = Code; 
             target.Name = Name;
             target.IsPrimary = IsPrimary;
             target.ExchangeRate = ExchangeRate;
             target.Symbol = Symbol;
             target.CustomFormatting = CustomFormatting;
+            target.MidpointRounding = MidpointRounding;
+            target.RoundingType = RoundingType;
         }
 
     }

diff --git a/src/VirtoCommerce.CoreModule.Data/Currency/CurrencyService.cs b/src/VirtoCommerce.CoreModule.Data/Currency/CurrencyService.cs
@@ -17,12 +17,14 @@ public class CurrencyService : ICurrencyService
         private readonly Func<ICoreRepository> _repositoryFactory;
         private readonly IEventPublisher _eventPublisher;
         private readonly IPlatformMemoryCache _platformMemoryCache;
+        private readonly IMoneyRoundingPolicy _moneyRoundingPolicy;
 
-        public CurrencyService(Func<ICoreRepository> repositoryFactory, IEventPublisher eventPublisher, IPlatformMemoryCache platformMemoryCache)
+        public CurrencyService(Func<ICoreRepository> repositoryFactory, IEventPublisher eventPublisher, IPlatformMemoryCache platformMemoryCache, IMoneyRoundingPolicy moneyRoundingPolicy)
         {
             _repositoryFactory = repositoryFactory;
             _eventPublisher = eventPublisher;
             _platformMemoryCache = platformMemoryCache;
+            _moneyRoundingPolicy = moneyRoundingPolicy;
         }
 
         public async Task<IEnumerable<Core.Currency.Currency>> GetAllCurrenciesAsync()
@@ -34,7 +36,12 @@ public CurrencyService(Func<ICoreRepository> repositoryFactory, IEventPublisher
                 using (var repository = _repositoryFactory())
                 {
                     var currencyEntities = await repository.Currencies.OrderByDescending(x => x.IsPrimary).ThenBy(x => x.Code).ToArrayAsync();
-                    var result = currencyEntities.Select(x => x.ToModel(AbstractTypeFactory<Core.Currency.Currency>.TryCreateInstance())).ToList();
+                    var result = currencyEntities.Select(x =>
+                    {
+                        var currency = x.ToModel(AbstractTypeFactory<Core.Currency.Currency>.TryCreateInstance());
+                        currency.RoundingPolicy = _moneyRoundingPolicy;
+                        return currency;
+                    }).ToList();
 
                     return result;
                 }