Move MathUtil methods to extensions (#432)

* Begin moving MathUtil methods to Extensions

* Add missing extension

Libraries/SPTarkov.Server.Core/Controllers/InsuranceController.cs

@@ -494,10 +494,7 @@ public class InsuranceController(
         );
 
         // Create prob array and add all attachments with rouble price as the weight
-        var attachmentsProbabilityArray = new ProbabilityObjectArray<string, double?>(
-            _mathUtil,
-            _cloner
-        );
+        var attachmentsProbabilityArray = new ProbabilityObjectArray<string, double?>(_cloner);
         foreach (var (itemTpl, price) in weightedAttachmentByPrice)
         {
             attachmentsProbabilityArray.Add(
@@ -507,7 +504,7 @@ public class InsuranceController(
 
         // Draw x attachments from weighted array to remove from parent, remove from pool after being picked
         var attachmentIdsToRemove = attachmentsProbabilityArray.Draw(
-            (int)countOfAttachmentsToRemove,
+            (int) countOfAttachmentsToRemove,
             false
         );
         foreach (var attachmentId in attachmentIdsToRemove)

Libraries/SPTarkov.Server.Core/Controllers/RepeatableQuestController.cs

@@ -881,7 +881,6 @@ public class RepeatableQuestController(
             repeatableConfig
         );
         var targetsConfig = new ProbabilityObjectArray<string, BossInfo>(
-            _mathUtil,
             _cloner,
             eliminationConfig.Targets
         );

Libraries/SPTarkov.Server.Core/Extensions/MathExtensions.cs

@@ -0,0 +1,59 @@
+namespace SPTarkov.Server.Core.Extensions
+{
+    public static class MathExtensions
+    {
+        /// <summary>
+        ///     Helper to create the cumulative sum of all enumerable elements
+        ///     [1, 2, 3, 4].CumulativeSum() = [1, 3, 6, 10]
+        /// </summary>
+        /// <param name="values">The enumerable with numbers of which to calculate the cumulative sum</param>
+        /// <returns>cumulative sum of values</returns>
+        public static IEnumerable<double> CumulativeSum(this IEnumerable<double> values)
+        {
+            double sum = 0;
+            foreach (var value in values)
+            {
+                sum += value;
+                yield return sum;
+            }
+        }
+
+        /// <summary>
+        ///     Helper to create the cumulative sum of all enumerable elements
+        ///     [1, 2, 3, 4].CumulativeSum() = [1, 3, 6, 10]
+        /// </summary>
+        /// <param name="values">The enumerable with numbers of which to calculate the cumulative sum</param>
+        /// <returns>cumulative sum of values</returns>
+        public static IEnumerable<float> CumulativeSum(this IEnumerable<float> values)
+        {
+            float sum = 0;
+            foreach (var value in values)
+            {
+                sum += value;
+                yield return sum;
+            }
+        }
+
+        /// <summary>
+        ///     Helper to create the product of each element times factor
+        /// </summary>
+        /// <param name="values">The enumerable of numbers which shall be multiplied by the factor</param>
+        /// <param name="factor">Number to multiply each element by</param>
+        /// <returns>An enumerable of elements all multiplied by the factor</returns>
+        public static IEnumerable<double> Product(this IEnumerable<double> values, double factor)
+        {
+            return values.Select(v => v * factor);
+        }
+
+        /// <summary>
+        ///     Helper to create the product of each element times factor
+        /// </summary>
+        /// <param name="values">The enumerable of numbers which shall be multiplied by the factor</param>
+        /// <param name="factor">Number to multiply each element by</param>
+        /// <returns>An enumerable of elements all multiplied by the factor</returns>
+        public static IEnumerable<float> Product(this IEnumerable<float> values, float factor)
+        {
+            return values.Select(v => v * factor);
+        }
+    }
+}

Libraries/SPTarkov.Server.Core/Generators/LocationLootGenerator.cs

@@ -401,14 +401,14 @@ public class LocationLootGenerator(
         }
 
         // Create probability array with all possible container ids in this group and their relative probability of spawning
-        var containerDistribution = new ProbabilityObjectArray<string, double>(_mathUtil, _cloner);
+        var containerDistribution = new ProbabilityObjectArray<string, double>(_cloner);
         foreach (var x in containerIds)
         {
             var value = containerData.ContainerIdsWithProbability[x];
             containerDistribution.Add(new ProbabilityObject<string, double>(x, value, value));
         }
 
-        chosenContainerIds.AddRange(containerDistribution.Draw((int)containerData.ChosenCount));
+        chosenContainerIds.AddRange(containerDistribution.Draw((int) containerData.ChosenCount));
 
         return chosenContainerIds;
     }
@@ -653,7 +653,7 @@ public class LocationLootGenerator(
     )
     {
         // Create probability array to calculate the total count of lootable items inside container
-        var itemCountArray = new ProbabilityObjectArray<int, float?>(_mathUtil, _cloner);
+        var itemCountArray = new ProbabilityObjectArray<int, float?>(_cloner);
         var countDistribution = staticLootDist[containerTypeId]?.ItemCountDistribution;
         if (countDistribution is null)
         {
@@ -698,7 +698,7 @@ public class LocationLootGenerator(
         var seasonalEventActive = _seasonalEventService.SeasonalEventEnabled();
         var seasonalItemTplBlacklist = _seasonalEventService.GetInactiveSeasonalEventItems();
 
-        var itemDistribution = new ProbabilityObjectArray<string, float?>(_mathUtil, _cloner);
+        var itemDistribution = new ProbabilityObjectArray<string, float?>(_cloner);
 
         var itemContainerDistribution = staticLootDist[containerTypeId]?.ItemDistribution;
         if (itemContainerDistribution is null)
@@ -804,7 +804,7 @@ public class LocationLootGenerator(
         );
 
         // Init empty array to hold spawn points, letting us pick them pseudo-randomly
-        var spawnPointArray = new ProbabilityObjectArray<string, Spawnpoint>(_mathUtil, _cloner);
+        var spawnPointArray = new ProbabilityObjectArray<string, Spawnpoint>(_cloner);
 
         // Positions not in forced but have 100% chance to spawn
         List<Spawnpoint> guaranteedLoosePoints = [];
@@ -855,7 +855,7 @@ public class LocationLootGenerator(
         if (randomSpawnPointCount > 0 && spawnPointArray.Count > 0)
         // Add randomly chosen spawn points
         {
-            foreach (var si in spawnPointArray.Draw((int)randomSpawnPointCount, false))
+            foreach (var si in spawnPointArray.Draw((int) randomSpawnPointCount, false))
             {
                 chosenSpawnPoints.Add(spawnPointArray.Data(si));
             }
@@ -940,7 +940,7 @@ public class LocationLootGenerator(
             var validItemIds = spawnPoint.Template.Items.Select(item => item.Id).ToHashSet();
 
             // Construct container to hold above filtered items, letting us pick an item for the spot
-            var itemArray = new ProbabilityObjectArray<string, double?>(_mathUtil, _cloner);
+            var itemArray = new ProbabilityObjectArray<string, double?>(_cloner);
             foreach (var itemDist in spawnPoint.ItemDistribution)
             {
                 if (!validItemIds.Contains(itemDist.ComposedKey.Key))

Libraries/SPTarkov.Server.Core/Generators/RepeatableQuestGeneration/EliminationQuestGenerator.cs

@@ -333,22 +333,18 @@ public class EliminationQuestGenerator(
         var locationsConfig = repeatableConfig.Locations;
 
         var targetsConfig = new ProbabilityObjectArray<string, BossInfo>(
-            mathUtil,
             cloner,
             eliminationConfig.Targets
         );
         var bodyPartsConfig = new ProbabilityObjectArray<string, List<string>>(
-            mathUtil,
             cloner,
             eliminationConfig.BodyParts
         );
         var weaponCategoryRequirementConfig = new ProbabilityObjectArray<string, List<string>>(
-            mathUtil,
             cloner,
             eliminationConfig.WeaponCategoryRequirements
         );
         var weaponRequirementConfig = new ProbabilityObjectArray<string, List<string>>(
-            mathUtil,
             cloner,
             eliminationConfig.WeaponRequirements
         );
@@ -609,9 +605,9 @@ public class EliminationQuestGenerator(
                     + generationData.EliminationConfig.MinDistance
             );
 
-        distance = (int)Math.Ceiling((decimal)(distance / 5d)) * 5;
+        distance = (int) Math.Ceiling((decimal) (distance / 5d)) * 5;
 
-        var distanceDifficulty = (int)(
+        var distanceDifficulty = (int) (
             MaxDistDifficulty * distance / generationData.EliminationConfig.MaxDistance
         );
 
@@ -633,26 +629,26 @@ public class EliminationQuestGenerator(
         {
             // Filter out close range weapons from far distance requirement
             case > 50:
-            {
-                List<string> weaponTypeBlacklist = ["Shotgun", "Pistol"];
+                {
+                    List<string> weaponTypeBlacklist = ["Shotgun", "Pistol"];
 
-                // Filter out close range weapons from long distance requirement
-                generationData.WeaponCategoryRequirementConfig.RemoveAll(category =>
-                    weaponTypeBlacklist.Contains(category.Key)
-                );
-                break;
-            }
+                    // Filter out close range weapons from long distance requirement
+                    generationData.WeaponCategoryRequirementConfig.RemoveAll(category =>
+                        weaponTypeBlacklist.Contains(category.Key)
+                    );
+                    break;
+                }
             // Filter out long range weapons from close distance requirement
             case < 20:
-            {
-                List<string> weaponTypeBlacklist = ["MarksmanRifle", "DMR"];
+                {
+                    List<string> weaponTypeBlacklist = ["MarksmanRifle", "DMR"];
 
-                // Filter out far range weapons from close distance requirement
-                generationData.WeaponCategoryRequirementConfig.RemoveAll(category =>
-                    weaponTypeBlacklist.Contains(category.Key)
-                );
-                break;
-            }
+                    // Filter out far range weapons from close distance requirement
+                    generationData.WeaponCategoryRequirementConfig.RemoveAll(category =>
+                        weaponTypeBlacklist.Contains(category.Key)
+                    );
+                    break;
+                }
         }
 
         // Pick a weighted weapon category

Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs

@@ -433,7 +433,7 @@ public class ItemHelper(
         // Run getItemPrice for each tpl in tpls array, return sum
         return tpls.Aggregate(
             0,
-            (total, tpl) => total + (int)GetItemPrice(tpl).GetValueOrDefault(0)
+            (total, tpl) => total + (int) GetItemPrice(tpl).GetValueOrDefault(0)
         );
     }
 
@@ -902,8 +902,8 @@ public class ItemHelper(
         // Find required items to take after buying (handles multiple items)
         var desiredBarterIds =
             desiredBarterItemIds.GetType() == typeof(string)
-                ? [(string)desiredBarterItemIds]
-                : (List<string>)desiredBarterItemIds;
+                ? [(string) desiredBarterItemIds]
+                : (List<string>) desiredBarterItemIds;
 
         List<Item> matchingItems = [];
         foreach (var barterId in desiredBarterIds)
@@ -1456,7 +1456,7 @@ public class ItemHelper(
             var cartridgeItemToAdd = CreateCartridges(
                 ammoBox[0].Id,
                 cartridgeTpl,
-                (int)cartridgeCountToAdd,
+                (int) cartridgeCountToAdd,
                 location
             );
 
@@ -1485,7 +1485,7 @@ public class ItemHelper(
             0
         ].Filter?.FirstOrDefault();
         ammoBox.Add(
-            CreateCartridges(ammoBox[0].Id, cartridgeTpl, (int)ammoBoxMaxCartridgeCount, 0)
+            CreateCartridges(ammoBox[0].Id, cartridgeTpl, (int) ammoBoxMaxCartridgeCount, 0)
         );
     }
 
@@ -1593,8 +1593,8 @@ public class ItemHelper(
         }
 
         var desiredStackCount = _randomUtil.GetInt(
-            (int)Math.Round(minSizeMultiplier * magazineCartridgeMaxCount ?? 0),
-            (int)magazineCartridgeMaxCount
+            (int) Math.Round(minSizeMultiplier * magazineCartridgeMaxCount ?? 0),
+            (int) magazineCartridgeMaxCount
         );
 
         if (magazineWithChildCartridges.Count > 1)
@@ -1693,7 +1693,7 @@ public class ItemHelper(
             return null;
         }
 
-        var ammoArray = new ProbabilityObjectArray<string, float?>(_mathUtil, _cloner);
+        var ammoArray = new ProbabilityObjectArray<string, float?>(_cloner);
         foreach (var icd in ammos)
         {
             // Whitelist exists and tpl not inside it, skip
@@ -1706,7 +1706,7 @@ public class ItemHelper(
             ammoArray.Add(
                 new ProbabilityObject<string, float?>(
                     icd.Tpl,
-                    (double)icd.RelativeProbability,
+                    (double) icd.RelativeProbability,
                     null
                 )
             );

Libraries/SPTarkov.Server.Core/Utils/Collections/ProbabilityObjectArray.cs

@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using SPTarkov.Server.Core.Extensions;
 using SPTarkov.Server.Core.Utils.Cloners;
 
 namespace SPTarkov.Server.Core.Utils.Collections;
@@ -23,16 +24,13 @@ namespace SPTarkov.Server.Core.Utils.Collections;
 public class ProbabilityObjectArray<K, V> : List<ProbabilityObject<K, V>>
 {
     private readonly ICloner _cloner;
-    private readonly MathUtil _mathUtil;
 
     public ProbabilityObjectArray(
-        MathUtil mathUtil,
         ICloner cloner,
         ICollection<ProbabilityObject<K, V>>? items = null
     )
         : base(items ?? [])
     {
-        _mathUtil = mathUtil;
         _cloner = cloner;
     }
 
@@ -43,11 +41,11 @@ public class ProbabilityObjectArray<K, V> : List<ProbabilityObject<K, V>>
     /// <returns>Cumulative Sum normalized to 1</returns>
     public List<double> CumulativeProbability(List<double> probValues)
     {
-        var sum = _mathUtil.ListSum(probValues);
-        var probCumsum = _mathUtil.ListCumSum(probValues);
-        probCumsum = _mathUtil.ListProduct(probCumsum, 1D / sum);
+        var sum = probValues.Sum();
+        var probCumsum = probValues.CumulativeSum();
+        probCumsum = probCumsum.Product(1D / sum);
 
-        return probCumsum;
+        return probCumsum.ToList();
     }
 
     /// <summary>
@@ -57,11 +55,7 @@ public class ProbabilityObjectArray<K, V> : List<ProbabilityObject<K, V>>
     /// <returns>Filtered results</returns>
     public ProbabilityObjectArray<K, V> Filter(Predicate<ProbabilityObject<K, V>> predicate)
     {
-        var result = new ProbabilityObjectArray<K, V>(
-            _mathUtil,
-            _cloner,
-            new List<ProbabilityObject<K, V>>()
-        );
+        var result = new ProbabilityObjectArray<K, V>(_cloner, new List<ProbabilityObject<K, V>>());
         foreach (var probabilityObject in this)
         {
             if (predicate.Invoke(probabilityObject))
@@ -81,7 +75,6 @@ public class ProbabilityObjectArray<K, V> : List<ProbabilityObject<K, V>>
     {
         var clone = _cloner.Clone(this);
         var probabilityObjects = new ProbabilityObjectArray<K, V>(
-            _mathUtil,
             _cloner,
             new List<ProbabilityObject<K, V>>()
         );
@@ -97,7 +90,7 @@ public class ProbabilityObjectArray<K, V> : List<ProbabilityObject<K, V>>
     /// <returns>ProbabilityObjectArray without the dropped element</returns>
     public ProbabilityObjectArray<K, V> Drop(K key)
     {
-        return (ProbabilityObjectArray<K, V>)this.Where(r => !r.Key?.Equals(key) ?? false);
+        return (ProbabilityObjectArray<K, V>) this.Where(r => !r.Key?.Equals(key) ?? false);
     }
 
     /// <summary>

Libraries/SPTarkov.Server.Core/Utils/MathUtil.cs

@@ -6,58 +6,6 @@ namespace SPTarkov.Server.Core.Utils;
 [Injectable(InjectionType.Singleton)]
 public class MathUtil
 {
-    /// <summary>
-    ///     Helper to create the sum of all list elements
-    /// </summary>
-    /// <param name="values">List of floats to sum</param>
-    /// <returns>sum of all values</returns>
-    public double ListSum(List<double> values)
-    {
-        // Sum the list starting with an initial value of 0
-        return values.Sum();
-    }
-
-    public float ListSum(List<float> values)
-    {
-        // Sum the list starting with an initial value of 0
-        return values.Sum();
-    }
-
-    /// <summary>
-    ///     Helper to create the cumulative sum of all list elements
-    ///     ListCumSum([1, 2, 3, 4]) = [1, 3, 6, 10]
-    /// </summary>
-    /// <param name="values">The list with numbers of which to calculate the cumulative sum</param>
-    /// <returns>cumulative sum of values</returns>
-    public List<double> ListCumSum(List<double> values)
-    {
-        if (values.Count == 0)
-        {
-            return [];
-        }
-
-        var cumSumArray = new double[values.Count];
-        cumSumArray[0] = values[0];
-
-        for (var i = 1; i < values.Count; i++)
-        {
-            cumSumArray[i] = cumSumArray[i - 1] + values[i];
-        }
-
-        return [.. cumSumArray];
-    }
-
-    /// <summary>
-    ///     Helper to create the product of each element times factor
-    /// </summary>
-    /// <param name="values">The list of numbers which shall be multiplied by the factor</param>
-    /// <param name="factor">Number to multiply each element by</param>
-    /// <returns>A list of elements all multiplied by the factor</returns>
-    public List<double> ListProduct(List<double> values, double factor)
-    {
-        return values.Select(v => v * factor).ToList();
-    }
-
     /// <summary>
     ///     Helper to add a constant to all list elements
     /// </summary>

UnitTests/Tests/Utils/MathUtilTests.cs

@@ -1,3 +1,4 @@
+using SPTarkov.Server.Core.Extensions;
 using SPTarkov.Server.Core.Utils;
 
 namespace UnitTests.Tests.Utils;
@@ -19,7 +20,7 @@ public class MathUtilTests
         var test = new List<float> { 1.1f, 2.1f, 3.3f };
         const double expected = 6.5f;
 
-        var actual = _mathUtil.ListSum(test);
+        var actual = test.Sum();
 
         Assert.AreEqual(expected, actual, $"ListSum() Expected: {expected}, Actual: {actual}");
     }
@@ -30,7 +31,7 @@ public class MathUtilTests
         var test = new List<double> { 1f, 2f, 3f, 4f };
         var expected = new List<double> { 1f, 3f, 6f, 10f };
 
-        var actual = _mathUtil.ListCumSum(test);
+        var actual = test.CumulativeSum().ToList();
 
         for (var i = 0; i < actual.Count; i++)
         {
@@ -49,7 +50,7 @@ public class MathUtilTests
         var test = new List<double> { 1f, 2f, 3f, 4f };
         var expected = new List<double> { 2f, 4f, 6f, 8f };
 
-        var actual = _mathUtil.ListProduct(test, 2);
+        var actual = test.Product(2).ToList();
 
         for (var i = 0; i < actual.Count; i++)
         {