feat: respect Discord permissions in pk;message and pk;edit

PluralKit.Bot/CommandSystem/ContextChecksExt.cs

@@ -1,7 +1,9 @@
 using System.Linq;
+using System.Threading.Tasks;
 
 using Autofac;
 
+using Myriad.Extensions;
 using Myriad.Types;
 
 using PluralKit.Core;
@@ -57,6 +59,28 @@ namespace PluralKit.Bot
             return ctx;
         }
 
+        public static async Task<bool> CheckPermissionsInGuildChannel(this Context ctx, Channel channel, PermissionSet neededPerms)
+        {
+            var guild = ctx.Cache.GetGuild(channel.GuildId.Value);
+            if (guild == null)
+                return false;
+
+            var guildMember = ctx.Member;
+
+            if (ctx.Guild?.Id != channel.GuildId)
+            {
+                guildMember = await ctx.Rest.GetGuildMember(channel.GuildId.Value, ctx.Author.Id);
+                if (guildMember == null)
+                    return false;
+            }
+
+            var userPermissions = PermissionExtensions.PermissionsFor(guild, channel, ctx.Author.Id, guildMember);
+            if ((userPermissions & neededPerms) == 0)
+                return false;
+
+            return true;
+        }
+
         public static bool CheckBotAdmin(this Context ctx)
         {
             var botConfig = ctx.Services.Resolve<BotConfig>();

PluralKit.Bot/Commands/Checks.cs

@@ -169,29 +169,15 @@ namespace PluralKit.Bot
                 throw new PKSyntaxError("You need to specify a channel.");
 
             var error = "Channel not found or you do not have permissions to access it.";
-
             var channel = await ctx.MatchChannel();
             if (channel == null || channel.GuildId == null)
                 throw new PKError(error);
 
-            var guild = _cache.GetGuild(channel.GuildId.Value);
+            if (!await ctx.CheckPermissionsInGuildChannel(channel, PermissionSet.ViewChannel))
-            if (guild == null)
                 throw new PKError(error);
 
-            var guildMember = await _rest.GetGuildMember(channel.GuildId.Value, ctx.Author.Id);
-            if (guildMember == null)
-                throw new PKError(error);
-
-
-
             var botPermissions = _bot.PermissionsIn(channel.Id);
             var webhookPermissions = _cache.EveryonePermissions(channel);
-            var userPermissions = PermissionExtensions.PermissionsFor(guild, channel, ctx.Author.Id, guildMember);
-
-            if ((userPermissions & PermissionSet.ViewChannel) == 0)
-                throw new PKError(error);
-
-
 
             // We use a bitfield so we can set individual permission bits
             ulong missingPermissions = 0;

PluralKit.Bot/Commands/Message.cs

@@ -105,6 +105,20 @@ namespace PluralKit.Bot
                     throw new PKError("Could not find a recent message to edit.");
             }
 
+            if (msg.Message.Channel != ctx.Channel.Id)
+            {
+                var error = "The channel where the message was sent does not exist anymore, or you are missing permissions to access it.";
+
+                var channel = _cache.GetChannel(msg.Message.Channel);
+                if (channel == null)
+                    throw new PKError(error);
+
+                if (!await ctx.CheckPermissionsInGuildChannel(channel,
+                    PermissionSet.ViewChannel | PermissionSet.SendMessages
+                ))
+                    throw new PKError(error);
+            }
+
             return msg;
         }
 
@@ -145,11 +159,20 @@ namespace PluralKit.Bot
                     throw Errors.MessageNotFound(messageId.Value);
             }
 
+            var showContent = true;
+            var noShowContentError = "Message deleted or inaccessible.";
+
+            var channel = _cache.GetChannel(message.Message.Channel);
+            if (channel == null)
+                showContent = false;
+            else if (!await ctx.CheckPermissionsInGuildChannel(channel, PermissionSet.ViewChannel))
+                showContent = false;
+
             if (ctx.MatchRaw())
             {
                 var discordMessage = await _rest.GetMessageOrNull(message.Message.Channel, message.Message.Mid);
-                if (discordMessage == null)
+                if (discordMessage == null || !showContent)
-                    throw new PKError("Message deleted or inaccessible.");
+                    throw new PKError(noShowContentError);
 
                 var content = discordMessage.Content;
                 if (content == null || content == "")
@@ -174,12 +197,15 @@ namespace PluralKit.Bot
 
             if (isDelete)
             {
+                if (!showContent)
+                    throw new PKError(noShowContentError);
+
                 if (message.System.Id != ctx.System.Id)
                     throw new PKError("You can only delete your own messages.");
 
                 await ctx.Rest.DeleteMessage(message.Message.Channel, message.Message.Mid);
 
-                if (ctx.Guild != null)
+                if (ctx.Channel.Id == message.Message.Channel)
                     await ctx.Rest.DeleteMessage(ctx.Message);
                 else
                     await ctx.Rest.CreateReaction(ctx.Message.ChannelId, ctx.Message.Id, new() { Name = Emojis.Success });
@@ -197,7 +223,7 @@ namespace PluralKit.Bot
                 return;
             }
 
-            await ctx.Reply(embed: await _embeds.CreateMessageInfoEmbed(message));
+            await ctx.Reply(embed: await _embeds.CreateMessageInfoEmbed(message, showContent));
         }
 
         private async Task DeleteCommandMessage(Context ctx, ulong messageId)

PluralKit.Bot/Handlers/ReactionAdded.cs

@@ -175,7 +175,7 @@ namespace PluralKit.Bot
 
                 await _rest.CreateMessage(dm.Id, new MessageRequest
                 {
-                    Embed = await _embeds.CreateMessageInfoEmbed(msg)
+                    Embed = await _embeds.CreateMessageInfoEmbed(msg, true)
                 });
             }
             catch (ForbiddenException) { } // No permissions to DM, can't check for this :(

PluralKit.Bot/Services/EmbedService.cs

@@ -275,7 +275,7 @@ namespace PluralKit.Bot
                 .Build();
         }
 
-        public async Task<Embed> CreateMessageInfoEmbed(FullMessage msg)
+        public async Task<Embed> CreateMessageInfoEmbed(FullMessage msg, bool showContent)
         {
             var channel = await _cache.GetOrFetchChannel(_rest, msg.Message.Channel);
             var ctx = LookupContext.ByNonOwner;
@@ -317,11 +317,15 @@ namespace PluralKit.Bot
             else if (userInfo != null) userStr = userInfo.NameAndMention();
             else userStr = $"*(deleted user {msg.Message.Sender})*";
 
+            var content = serverMsg?.Content?.NormalizeLineEndSpacing();
+            if (content == null || !showContent)
+                content = "*(message contents deleted or inaccessible)*";
+
             // Put it all together
             var eb = new EmbedBuilder()
                 .Author(new(msg.Member.NameFor(ctx), IconUrl: msg.Member.AvatarFor(ctx).TryGetCleanCdnUrl()))
-                .Description(serverMsg?.Content?.NormalizeLineEndSpacing() ?? "*(message contents deleted or inaccessible)*")
+                .Description(content)
-                .Image(new(serverMsg?.Attachments?.FirstOrDefault()?.Url))
+                .Image(showContent ? new(serverMsg?.Attachments?.FirstOrDefault()?.Url) : null)
                 .Field(new("System",
                     msg.System.Name != null ? $"{msg.System.Name} (`{msg.System.Hid}`)" : $"`{msg.System.Hid}`", true))
                 .Field(new("Member", $"{msg.Member.NameFor(ctx)} (`{msg.Member.Hid}`)", true))
@@ -329,7 +333,7 @@ namespace PluralKit.Bot
                 .Timestamp(DiscordUtils.SnowflakeToInstant(msg.Message.Mid).ToDateTimeOffset().ToString("O"));
 
             var roles = memberInfo?.Roles?.ToList();
-            if (roles != null && roles.Count > 0)
+            if (roles != null && roles.Count > 0 && showContent)
             {
                 var rolesString = string.Join(", ", roles
                     .Select(id =>