Moderation bot work

1 files changed, 113 insertions, 0 deletions

diff --git a/Commands/BanMediaCommand.cs b/Commands/BanMediaCommand.cs
new file mode 100644
index 0000000..21e0a94
--- /dev/null
+++ b/Commands/BanMediaCommand.cs
@@ -0,0 +1,113 @@
+using System.Buffers.Text;
+using System.Security.Cryptography;
+using ArcaneLibs.Extensions;
+using LibMatrix;
+using LibMatrix.EventTypes.Spec;
+using LibMatrix.Helpers;
+using LibMatrix.Services;
+using LibMatrix.Utilities.Bot.Interfaces;
+using ModerationBot.AccountData;
+using ModerationBot.StateEventTypes;
+using ModerationBot.StateEventTypes.Policies.Implementations;
+
+namespace ModerationBot.Commands;
+
+public class BanMediaCommand(IServiceProvider services, HomeserverProviderService hsProvider, HomeserverResolverService hsResolver, PolicyEngine engine) : ICommand {
+    public string Name { get; } = "banmedia";
+    public string Description { get; } = "Create a policy banning a piece of media, must be used in reply to a message";
+
+    public async Task<bool> CanInvoke(CommandContext ctx) {
+        //check if user is admin in control room
+        var botData = await ctx.Homeserver.GetAccountDataAsync<BotData>("gay.rory.moderation_bot_data");
+        var controlRoom = ctx.Homeserver.GetRoom(botData.ControlRoom);
+        var isAdmin = (await controlRoom.GetPowerLevelsAsync())!.UserHasPermission(ctx.MessageEvent.Sender, "m.room.ban");
+        if (!isAdmin) {
+            // await ctx.Reply("You do not have permission to use this command!");
+            await ctx.Homeserver.GetRoom(botData.LogRoom!).SendMessageEventAsync(
+                new RoomMessageEventContent(body: $"User {ctx.MessageEvent.Sender} tried to use command {Name} but does not have permission!", messageType: "m.text"));
+        }
+
+        return isAdmin;
+    }
+
+    public async Task Invoke(CommandContext ctx) {
+        
+        var botData = await ctx.Homeserver.GetAccountDataAsync<BotData>("gay.rory.moderation_bot_data");
+        var policyRoom = ctx.Homeserver.GetRoom(botData.DefaultPolicyRoom ?? botData.ControlRoom);
+        var logRoom = ctx.Homeserver.GetRoom(botData.LogRoom ?? botData.ControlRoom);
+
+        //check if reply
+        var messageContent = ctx.MessageEvent.TypedContent as RoomMessageEventContent;
+        if (messageContent?.RelatesTo is { InReplyTo: not null }) {
+            try {
+                await logRoom.SendMessageEventAsync(
+                    new RoomMessageEventContent(
+                        body: $"User {MessageFormatter.HtmlFormatMention(ctx.MessageEvent.Sender)} is trying to ban media {messageContent!.RelatesTo!.InReplyTo!.EventId}",
+                        messageType: "m.text"));
+
+                //get replied message
+                var repliedMessage = await ctx.Room.GetEventAsync<StateEventResponse>(messageContent.RelatesTo!.InReplyTo!.EventId);
+
+                //check if recommendation is in list
+                if (ctx.Args.Length < 2) {
+                    await ctx.Room.SendMessageEventAsync(MessageFormatter.FormatError("You must specify a recommendation type and reason!"));
+                    return;
+                }
+
+                var recommendation = ctx.Args[0];
+
+                if (recommendation is not ("ban" or "kick" or "mute" or "redact" or "spoiler" or "warn" or "warn_admins")) {
+                    await ctx.Room.SendMessageEventAsync(
+                        MessageFormatter.FormatError(
+                            $"Invalid recommendation type {recommendation}, must be `warn_admins`, `warn`, `spoiler`, `redact`, `mute`, `kick` or `ban`!"));
+                    return;
+                }
+
+                //hash file
+                var mxcUri = (repliedMessage.TypedContent as RoomMessageEventContent).Url!;
+                var resolvedUri = await hsResolver.ResolveMediaUri(mxcUri.Split('/')[2], mxcUri);
+                var hashAlgo = SHA3_256.Create();
+                var uriHash = hashAlgo.ComputeHash(mxcUri.AsBytes().ToArray());
+                byte[]? fileHash = null;
+
+                try {
+                    fileHash = await hashAlgo.ComputeHashAsync(await ctx.Homeserver.ClientHttpClient.GetStreamAsync(resolvedUri));
+                }
+                catch (Exception ex) {
+                    await logRoom.SendMessageEventAsync(
+                        MessageFormatter.FormatException($"Error calculating file hash for {mxcUri} via {mxcUri.Split('/')[2]}, retrying via {ctx.Homeserver.BaseUrl}...",
+                            ex));
+                    try {
+                        resolvedUri = await hsResolver.ResolveMediaUri(ctx.Homeserver.BaseUrl, mxcUri);
+                        fileHash = await hashAlgo.ComputeHashAsync(await ctx.Homeserver.ClientHttpClient.GetStreamAsync(resolvedUri));
+                    }
+                    catch (Exception ex2) {
+                        await ctx.Room.SendMessageEventAsync(MessageFormatter.FormatException("Error calculating file hash", ex2));
+                        await logRoom.SendMessageEventAsync(
+                            MessageFormatter.FormatException($"Error calculating file hash via {ctx.Homeserver.BaseUrl}!", ex2));
+                    }
+                }
+
+                MediaPolicyFile policy;
+                await policyRoom.SendStateEventAsync("gay.rory.moderation.rule.media", Guid.NewGuid().ToString(), policy = new MediaPolicyFile {
+                    Entity = Convert.ToBase64String(uriHash),
+                    FileHash = Convert.ToBase64String(fileHash),
+                    Reason = string.Join(' ', ctx.Args[1..]),
+                    Recommendation = recommendation,
+                });
+
+                await ctx.Room.SendMessageEventAsync(MessageFormatter.FormatSuccessJson("Media policy created", policy));
+                await logRoom.SendMessageEventAsync(MessageFormatter.FormatSuccessJson("Media policy created", policy));
+            }
+            catch (Exception e) {
+                await logRoom.SendMessageEventAsync(MessageFormatter.FormatException("Error creating policy", e));
+                await ctx.Room.SendMessageEventAsync(MessageFormatter.FormatException("Error creating policy", e));
+                await using var stream = new MemoryStream(e.ToString().AsBytes().ToArray());
+                await logRoom.SendFileAsync("error.log.cs", stream);
+            }
+        }
+        else {
+            await ctx.Room.SendMessageEventAsync(MessageFormatter.FormatError("This command must be used in reply to a message!"));
+        }
+    }
+}