Add super basic group model/command

PluralKit.Core/Models/GroupId.cs

@@ -0,0 +1,26 @@
+namespace PluralKit.Core
+{
+    public readonly struct GroupId: INumericId<GroupId, int>
+    {
+        public int Value { get; }
+
+        public GroupId(int value)
+        {
+            Value = value;
+        }
+
+        public bool Equals(GroupId other) => Value == other.Value;
+
+        public override bool Equals(object obj) => obj is GroupId other && Equals(other);
+
+        public override int GetHashCode() => Value;
+
+        public static bool operator ==(GroupId left, GroupId right) => left.Equals(right);
+
+        public static bool operator !=(GroupId left, GroupId right) => !left.Equals(right);
+
+        public int CompareTo(GroupId other) => Value.CompareTo(other.Value);
+        
+        public override string ToString() => $"Member #{Value}";
+    }
+}

PluralKit.Core/Models/ModelQueryExt.cs

@@ -29,6 +29,12 @@ namespace PluralKit.Core
         public static Task<PKMember?> QueryMemberByHid(this IPKConnection conn, string hid) =>
             conn.QueryFirstOrDefaultAsync<PKMember?>("select * from members where hid = @hid", new {hid = hid.ToLowerInvariant()});
         
+        public static Task<PKGroup?> QueryGroupByName(this IPKConnection conn, string name) =>
+            conn.QueryFirstOrDefaultAsync<PKGroup?>("select * from groups where lower(name) = lower(@name)", new {name = name});
+        
+        public static Task<PKGroup?> QueryGroupByHid(this IPKConnection conn, string hid) =>
+            conn.QueryFirstOrDefaultAsync<PKGroup?>("select * from groups where hid = @hid", new {hid = hid.ToLowerInvariant()});
+
         public static Task<GuildConfig> QueryOrInsertGuildConfig(this IPKConnection conn, ulong guild) =>
             conn.QueryFirstAsync<GuildConfig>("insert into servers (id) values (@guild) on conflict (id) do update set id = @guild returning *", new {guild});
 

PluralKit.Core/Models/PKGroup.cs

@@ -0,0 +1,17 @@
+using NodaTime;
+
+#nullable enable
+namespace PluralKit.Core
+{
+    public class PKGroup
+    {
+        public GroupId Id { get; }
+        public string Hid { get; } = null!;
+        public SystemId System { get; }
+
+        public string Name { get; } = null!;
+        public string? Description { get; }
+        
+        public Instant Created { get; }
+    }
+}

PluralKit.Core/Models/Patch/GroupPatch.cs

@@ -0,0 +1,13 @@
+#nullable enable
+namespace PluralKit.Core
+{
+    public class GroupPatch: PatchObject
+    {
+        public Partial<string> Name { get; set; }
+        public Partial<string?> Description { get; set; }
+
+        public override UpdateQueryBuilder Apply(UpdateQueryBuilder b) => b
+            .With("name", Name)
+            .With("description", Description);
+    }
+}

PluralKit.Core/Models/Patch/ModelPatchExt.cs

@@ -60,5 +60,10 @@ namespace PluralKit.Core
                 .Build();
             return conn.ExecuteAsync(query, pms);
         }
+        
+        public static Task<PKGroup> CreateGroup(this IPKConnection conn, SystemId system, string name) =>
+            conn.QueryFirstAsync<PKGroup>(
+                "insert into groups (hid, system, name) values (find_free_group_hid(), @System, @Name) returning *",
+                new {System = system, Name = name});
     }
 }