feat: add duplicate message collapsing

ChatTwo/Message.cs

@@ -15,6 +15,28 @@ internal class SortCode {
 
     public SortCode() {
     }
+
+    private bool Equals(SortCode other) {
+        return this.Type == other.Type && this.Source == other.Source;
+    }
+
+    public override bool Equals(object? obj) {
+        if (ReferenceEquals(null, obj)) {
+            return false;
+        }
+
+        if (ReferenceEquals(this, obj)) {
+            return true;
+        }
+
+        return obj.GetType() == this.GetType() && this.Equals((SortCode) obj);
+    }
+
+    public override int GetHashCode() {
+        unchecked {
+            return ((int) this.Type * 397) ^ (int) this.Source;
+        }
+    }
 }
 
 internal class Message {
@@ -38,6 +60,8 @@ internal class Message {
     internal SeString ContentSource { get; }
 
     internal SortCode SortCode { get; }
+    
+    internal int Hash { get; }
 
     internal Message(ulong receiver, ChatCode code, List<Chunk> sender, List<Chunk> content, SeString senderSource, SeString contentSource) {
         this.Receiver = receiver;
@@ -48,6 +72,7 @@ internal class Message {
         this.SenderSource = senderSource;
         this.ContentSource = contentSource;
         this.SortCode = new SortCode(this.Code.Type, this.Code.Source);
+        this.Hash = this.GenerateHash();
 
         foreach (var chunk in sender.Concat(content)) {
             chunk.Message = this;
@@ -65,9 +90,16 @@ internal class Message {
         this.SenderSource = BsonMapper.Global.Deserialize<SeString>(senderSource);
         this.ContentSource = BsonMapper.Global.Deserialize<SeString>(contentSource);
         this.SortCode = BsonMapper.Global.ToObject<SortCode>(sortCode);
+        this.Hash = this.GenerateHash();
 
         foreach (var chunk in this.Sender.Concat(this.Content)) {
             chunk.Message = this;
         }
     }
+
+    private int GenerateHash() {
+            return this.SortCode.GetHashCode()
+                    ^ string.Join("", this.Sender.Select(c => c.StringValue())).GetHashCode()
+                    ^ string.Join("", this.Content.Select(c => c.StringValue())).GetHashCode();
+    }
 }