Common: 倍率を表す構造体を追加 (#46)

Common/Master/SettingMaster.cs

@@ -70,11 +70,15 @@ private int GetInt(string key)
     /// </summary>
     public int MaxRareReplyProbabilityPermillage => GetInt(nameof(MaxRareReplyProbabilityPermillage));
 
+    public Multiplier MaxRareReplyProbability => Multiplier.FromPermillage(MaxRareReplyProbabilityPermillage);
+
     /// <summary>
     /// 確率返信の抽選単位(千分率)
     /// </summary>
     public int RareReplyProbabilityStepPermillage => GetInt(nameof(RareReplyProbabilityStepPermillage));
 
+    public Multiplier RareReplyProbabilityStep => Multiplier.FromPermillage(RareReplyProbabilityStepPermillage);
+
     /// <summary>
     /// 単発ガチャ1回の価格
     /// </summary>
@@ -120,15 +124,21 @@ private int GetInt(string key)
     /// </summary>
     public int SlotMaxConditionOffsetPermillage => GetInt(nameof(SlotMaxConditionOffsetPermillage));
 
+    public Multiplier SlotMaxConditionOffset => Multiplier.FromPermillage(SlotMaxConditionOffsetPermillage);
+
     /// <summary>
     /// スロットの調子の最小値(千分率)
     /// </summary>
     public int SlotMinConditionOffsetPermillage => GetInt(nameof(SlotMinConditionOffsetPermillage));
 
+    public Multiplier SlotMinConditionOffset => Multiplier.FromPermillage(SlotMinConditionOffsetPermillage);
+
     /// <summary>
     /// スロットの次に同じ出目が確定する確率の最大値(千分率)
     /// </summary>
     public int SlotRepeatPermillageUpperBound => GetInt(nameof(SlotRepeatPermillageUpperBound));
+
+    public Multiplier SlotRepeatUpperBound => Multiplier.FromPermillage(SlotRepeatPermillageUpperBound);
 }
 
 [SuppressMessage("ReSharper", "UnassignedGetOnlyAutoProperty")]

Common/Master/SlotItemMaster.cs

@@ -29,9 +29,13 @@ public class SlotItem : MasterRecord<string>
     [field: MasterIntValue("return_rate_permillage")]
     public int ReturnRatePermillage { get; }
 
+    public Multiplier ReturnRate => Multiplier.FromPermillage(ReturnRatePermillage);
+
     /// <summary>
     /// 次に同じ出目が確定する確率(千分率)
     /// </summary>
     [field: MasterIntValue("repeat_permillage")]
     public int RepeatPermillage { get; }
+
+    public Multiplier RepeatProbability => Multiplier.FromPermillage(RepeatPermillage);
 }

Common/Models/AppService.cs

@@ -7,10 +7,10 @@ namespace Approvers.King.Common;
 /// </summary>
 public class AppService : DbContext
 {
-    public DbSet<AppState> AppStates { get; set; }
     public DbSet<Slot> Slots { get; set; }
+    public DbSet<Gacha> Gachas { get; set; }
     public DbSet<User> Users { get; set; }
-    public DbSet<GachaProbability> GachaProbabilities { get; set; }
+    public DbSet<GachaItem> GachaItems { get; set; }
 
     /// <summary>
     /// セッションを作成する
@@ -41,7 +41,7 @@ public async Task<User> FindOrCreateUserAsync(ulong discordId)
         Add(user);
         return user;
     }
-    
+
     public async Task<Slot> GetDefaultSlotAsync()
     {
         var slot = await Slots.FirstOrDefaultAsync();
@@ -54,4 +54,17 @@ public async Task<Slot> GetDefaultSlotAsync()
         Add(slot);
         return slot;
     }
+
+    public async Task<Gacha> GetDefaultGachaAsync()
+    {
+        var gacha = await Gachas.Include(x => x.GachaItems).FirstOrDefaultAsync();
+        if (gacha != null)
+        {
+            return gacha;
+        }
+
+        gacha = new Gacha { Id = Guid.NewGuid() };
+        Add(gacha);
+        return gacha;
+    }
 }

Common/Models/Gacha.cs

@@ -0,0 +1,112 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace Approvers.King.Common;
+
+public class Gacha
+{
+    [Key] public Guid Id { get; set; }
+
+    public int HitProbabilityPermillage { get; set; }
+
+    /// <summary>
+    /// 現在のメッセージに反応する確率
+    /// </summary>
+    [NotMapped]
+    public Multiplier HitProbability
+    {
+        get => Multiplier.FromPermillage(HitProbabilityPermillage);
+        set => HitProbabilityPermillage = value.Permillage;
+    }
+
+    /// <summary>
+    /// 各メッセージの確率
+    /// </summary>
+    public List<GachaItem> GachaItems { get; set; } = [];
+
+    /// <summary>
+    /// 単発ガチャを回す
+    /// </summary>
+    public GachaItem? RollOnce()
+    {
+        if (RandomManager.IsHit(HitProbability) == false)
+        {
+            return null;
+        }
+
+        return GetRandomResult();
+    }
+
+    /// <summary>
+    /// 確定ガチャを回す
+    /// </summary>
+    public GachaItem RollOnceCertain()
+    {
+        return GetRandomResult();
+    }
+
+    private GachaItem GetRandomResult()
+    {
+        var total = GachaItems.Sum(x => x.Probability.Permillage);
+        if (total <= 0)
+        {
+            return GachaItems.First();
+        }
+
+        var value = RandomManager.GetRandomInt(total);
+
+        foreach (var element in GachaItems)
+        {
+            if (value < element.Probability.Permillage) return element;
+            value -= element.Probability.Permillage;
+        }
+
+        return GachaItems.Last();
+    }
+
+    /// <summary>
+    /// メッセージに反応する確率を再抽選する
+    /// </summary>
+    public void ShuffleRareReplyRate()
+    {
+        // 確率は step の単位で max まで変動（ただし0にはならない）
+        var step = MasterManager.SettingMaster.RareReplyProbabilityStep;
+        var max = MasterManager.SettingMaster.MaxRareReplyProbability;
+        var rates = Enumerable.Range(0, max.Permillage / step.Permillage).Select(i => step * (i + 1));
+        HitProbability = RandomManager.PickRandom(rates);
+    }
+
+    /// <summary>
+    /// 各メッセージの確率を再抽選する
+    /// </summary>
+    public void ShuffleMessageRates()
+    {
+        var items = MasterManager.RandomMessageMaster
+            .GetAll(x => x.Type == RandomMessageType.GeneralReply)
+            .Select(randomMessage => GachaItems.FirstOrDefault(item => item.RandomMessageId == randomMessage.Id) ?? new GachaItem()
+            {
+                GachaId = Id,
+                RandomMessageId = randomMessage.Id,
+                Probability = Multiplier.Zero
+            })
+            .ToList();
+
+        // いい感じに確率がばらけるように、カイ二乗分布を適用
+        var borders = Enumerable.Range(0, items.Count - 1)
+            .Select(_ => (float)Math.Pow(RandomManager.GetRandomFloat(1f), 2))
+            .Select(Multiplier.FromRate)
+            .OrderBy(x => x)
+            .ToList();
+        borders.Add(Multiplier.One);
+        var randomIndices = RandomManager.Shuffle(Enumerable.Range(0, items.Count)).ToList();
+
+        items[randomIndices[0]].Probability = borders[0];
+        for (var i = 1; i < items.Count; i++)
+        {
+            items[randomIndices[i]].Probability = borders[i] - borders[i - 1];
+        }
+
+        GachaItems.Clear();
+        GachaItems.AddRange(items);
+    }
+}

Common/Models/GachaItem.cs

@@ -0,0 +1,27 @@
+using System.ComponentModel.DataAnnotations.Schema;
+using Microsoft.EntityFrameworkCore;
+
+namespace Approvers.King.Common;
+
+[PrimaryKey(nameof(GachaId), nameof(RandomMessageId))]
+public class GachaItem
+{
+    public Guid GachaId { get; set; }
+    public Gacha Gacha { get; set; } = null!;
+    public string RandomMessageId { get; set; } = null!;
+
+    public int ProbabilityPermillage { get; set; }
+
+    [NotMapped]
+    public Multiplier Probability
+    {
+        get => Multiplier.FromPermillage(ProbabilityPermillage);
+        set => ProbabilityPermillage = value.Permillage;
+    }
+
+    private RandomMessage? _randomMessage;
+
+    public RandomMessage? RandomMessage => _randomMessage == null || _randomMessage.Id != RandomMessageId
+        ? _randomMessage = MasterManager.RandomMessageMaster.Find(RandomMessageId)
+        : _randomMessage;
+}