Add group add/remove commands

PluralKit.Bot/Commands/CommandTree.cs

@@ -50,6 +50,8 @@ namespace PluralKit.Bot
         public static Command GroupList = new Command("group list", "group list", "Lists all groups in this system");
         public static Command GroupRename = new Command("group rename", "group <group> name <new name>", "Renames a group");
         public static Command GroupDesc = new Command("group description", "group <group> description [description]", "Changes a group's description");
+        public static Command GroupAdd = new Command("group add", "group <group> add <member> [member 2] [member 3...]", "Adds one or more members to a group");
+        public static Command GroupRemove = new Command("group remove", "group <group> remove <member> [member 2] [member 3...]", "Removes one or more members from a group");
         public static Command Switch = new Command("switch", "switch <member> [member 2] [member 3...]", "Registers a switch");
         public static Command SwitchOut = new Command("switch out", "switch out", "Registers a switch with no members");
         public static Command SwitchMove = new Command("switch move", "switch move <date/time>", "Moves the latest switch in time");
@@ -333,6 +335,10 @@ namespace PluralKit.Bot
                     await ctx.Execute<Groups>(GroupRename, g => g.RenameGroup(ctx, target));
                 else if (ctx.Match("description", "info", "bio", "text", "desc"))
                     await ctx.Execute<Groups>(GroupDesc, g => g.GroupDescription(ctx, target));
+                else if (ctx.Match("add", "a"))
+                    await ctx.Execute<Groups>(GroupAdd,g => g.AddRemoveMembers(ctx, target, Groups.AddRemoveOperation.Add));
+                else if (ctx.Match("remove", "rem", "r"))
+                    await ctx.Execute<Groups>(GroupRemove, g => g.AddRemoveMembers(ctx, target, Groups.AddRemoveOperation.Remove));
                 else if (!ctx.HasNext())
                     await ctx.Execute<Groups>(GroupInfo, g => g.ShowGroupCard(ctx, target));
                 else

PluralKit.Bot/Commands/Groups.cs

@@ -144,6 +144,44 @@ namespace PluralKit.Bot
             await ctx.Reply(embed: eb.Build());
         }
 
+        public async Task AddRemoveMembers(Context ctx, PKGroup target, AddRemoveOperation op)
+        {
+            ctx.CheckOwnGroup(target);
+            
+            // Parse all arguments
+            var members = new List<PKMember>();
+            while (ctx.HasNext())
+            {
+                var member = await ctx.MatchMember();
+                if (member == null)
+                    throw new PKSyntaxError(ctx.CreateMemberNotFoundError(ctx.PopArgument()));;
+                if (member.System != target.System)
+                    throw new PKError($"Member **{member.Name}** (`{member.Hid}`) is not in your own system, so you can't add it to a group.");
+                members.Add(member);
+            }
+
+            if (members.Count == 0)
+                throw new PKSyntaxError("You must pass one or more members.");
+
+            await using var conn = await _db.Obtain();
+            if (op == AddRemoveOperation.Add)
+            {
+                await conn.AddMembersToGroup(target.Id, members.Select(m => m.Id));
+                await ctx.Reply($"{Emojis.Success} Members added to group.");
+            }
+            else if (op == AddRemoveOperation.Remove)
+            {
+                await conn.RemoveMembersFromGroup(target.Id, members.Select(m => m.Id));
+                await ctx.Reply($"{Emojis.Success} Members removed from group.");
+            }
+        }
+
+        public enum AddRemoveOperation
+        {
+            Add,
+            Remove
+        }
+
         private static async Task<PKSystem> GetGroupSystem(Context ctx, PKGroup target, IPKConnection conn)
         {
             var system = ctx.System;

PluralKit.Core/Models/Patch/ModelPatchExt.cs

@@ -1,4 +1,6 @@
-using System.Threading.Tasks;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
 
 using Dapper;
 
@@ -73,5 +75,21 @@ namespace PluralKit.Core
                 .Build("returning *");
             return conn.QueryFirstAsync<PKGroup>(query, pms);
         }
+
+        public static async Task AddMembersToGroup(this IPKConnection conn, GroupId group, IEnumerable<MemberId> members)
+        {
+            await using var w = conn.BeginBinaryImport("copy group_members (group_id, member_id) from stdin (format binary)");
+            foreach (var member in members)
+            {
+                await w.StartRowAsync();
+                await w.WriteAsync(group.Value);
+                await w.WriteAsync(member.Value);
+            }
+            await w.CompleteAsync();
+        }
+        
+        public static Task RemoveMembersFromGroup(this IPKConnection conn, GroupId group, IEnumerable<MemberId> members) =>
+            conn.ExecuteAsync("delete from group_members where group_id = @Group and member_id = any(@Members)",
+                new {Group = group, Members = members.ToArray() });
     }
 }