Add basic message interceptor framework

Signed-off-by: TheArcaneBrony <myrainbowdash949@gmail.com>

src/api/routes/channels/#channel_id/messages/index.ts

@@ -289,7 +289,7 @@ router.post(
 			edited_timestamp: undefined,
 			timestamp: new Date(),
 		});
-
+		if (message.id == "0") return res.json(message); // Don't handle cancelled messages.
 		channel.last_message_id = message.id;
 
 		if (channel.isDm()) {

src/api/util/handlers/Message.ts

@@ -40,12 +40,14 @@ import {
 	Config,
 	Sticker,
 	MessageCreateSchema,
-	EmbedCache,
+	EmbedCache, MessageOptions,
 } from "@fosscord/util";
 import { HTTPError } from "lambert-server";
 import { In } from "typeorm";
 import { EmbedHandlers } from "@fosscord/api";
 import * as Sentry from "@sentry/node";
+import { MessageInterceptResult } from "@fosscord/util/message_interceptors/IMessageInterceptor";
+import { PluralCommandInterceptor } from "../../../util/message_interceptors/plural_tooling/PluralCommandInterceptor";
 const allow_empty = false;
 // TODO: check webhook, application, system author, stickers
 // TODO: embed gifs/videos/images
@@ -53,6 +55,26 @@ const allow_empty = false;
 const LINK_REGEX =
 	/https?:\/\/(www\.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_+.~#?&//=]*)/g;
 
+const interceptors = [new PluralCommandInterceptor()];
+
+async function runMessageInterceptors(ctx: { message: Message, opts: MessageOptions }): Promise<MessageInterceptResult> {
+	const result = new MessageInterceptResult();
+	result.cancel = false;
+	result.message = ctx.message;
+	for (const interceptorsKey in interceptors) {
+		const interceptor = interceptors[interceptorsKey];
+		const interceptorResult = await interceptor.execute(ctx);
+
+		result.message = interceptorResult.message;
+		if (interceptorResult.cancel) {
+			result.cancel = true;
+			break;
+		}
+	}
+
+	return result;
+}
+
 export async function handleMessage(opts: MessageOptions): Promise<Message> {
 	const channel = await Channel.findOneOrFail({
 		where: { id: opts.channel_id },
@@ -192,11 +214,22 @@ export async function handleMessage(opts: MessageOptions): Promise<Message> {
 
 	// TODO: check and put it all in the body
 
+	// root@Rory - 2023-02-18 - Add message interceptors, for use in dev/plurality, might be useful for plugins too.
+	let interceptMessageResult: MessageInterceptResult = await runMessageInterceptors({
+		opts,
+		message,
+	});
+	if(interceptMessageResult.cancel) {
+		message.id = "0"; //identify as cancelled message, as to prevent it from being distributed
+		return message;
+	}
+
 	return message;
 }
 
 // TODO: cache link result in db
 export async function postHandleMessage(message: Message) {
+	if (message.id == "0") return; // don't handle cancelled messages
 	const content = message.content?.replace(/ *`[^)]*` */g, ""); // remove markdown
 	let links = content?.match(LINK_REGEX);
 	if (!links) return;
@@ -268,7 +301,7 @@ export async function postHandleMessage(message: Message) {
 
 export async function sendMessage(opts: MessageOptions) {
 	const message = await handleMessage({ ...opts, timestamp: new Date() });
-
+	if (message.id == "0") return; // don't handle cancelled messages
 	await Promise.all([
 		Message.insert(message),
 		emitEvent({
@@ -285,17 +318,3 @@ export async function sendMessage(opts: MessageOptions) {
 
 	return message;
 }
-
-interface MessageOptions extends MessageCreateSchema {
-	id?: string;
-	type?: MessageType;
-	pinned?: boolean;
-	author_id?: string;
-	webhook_id?: string;
-	application_id?: string;
-	embeds?: Embed[];
-	channel_id?: string;
-	attachments?: Attachment[];
-	edited_timestamp?: Date;
-	timestamp?: Date;
-}

src/util/entities/Message.ts

@@ -217,6 +217,8 @@ export class Message extends BaseClass {
 
 	@Column({ type: "simple-json", nullable: true })
 	components?: MessageComponent[];
+
+	ephemeral?: boolean;
 }
 
 export interface MessageComponent {

src/util/index.ts

@@ -25,3 +25,4 @@ export * from "./dtos/index";
 export * from "./schemas";
 export * from "./imports";
 export * from "./config";
+export * from "./message_interceptors";

src/util/interfaces/MessageOptions.ts

@@ -0,0 +1,15 @@
+import { Attachment, Embed, MessageCreateSchema, MessageType } from "@fosscord/util*";
+
+export interface MessageOptions extends MessageCreateSchema {
+    id?: string;
+    type?: MessageType;
+    pinned?: boolean;
+    author_id?: string;
+    webhook_id?: string;
+    application_id?: string;
+    embeds?: Embed[];
+    channel_id?: string;
+    attachments?: Attachment[];
+    edited_timestamp?: Date;
+    timestamp?: Date;
+}

src/util/interfaces/index.ts

@@ -21,3 +21,4 @@ export * from "./Presence";
 export * from "./Interaction";
 export * from "./Event";
 export * from "./Status";
+export * from "./MessageOptions";

src/util/message_interceptors/IMessageInterceptor.ts

@@ -0,0 +1,15 @@
+import { Message, MessageOptions } from "@fosscord/util";
+
+export interface IMessageInterceptor {
+    execute(ctx: MessageInterceptorContext): Promise<MessageInterceptResult>;
+}
+
+export class MessageInterceptResult {
+    cancel: boolean;
+    message: Message;
+}
+
+export class MessageInterceptorContext {
+    message: Message;
+    opts: MessageOptions;
+}

src/util/message_interceptors/index.ts

@@ -0,0 +1 @@
+export * from "./IMessageInterceptor";

src/util/message_interceptors/plural_tooling/PluralCommandInterceptor.ts

@@ -0,0 +1,46 @@
+import {
+    emitEvent,
+    IMessageInterceptor, Message,
+    MessageCreateEvent, MessageDeleteEvent, MessageFlags,
+    MessageInterceptorContext,
+    MessageInterceptResult, MessageTypes
+} from "@fosscord/util";
+
+export class PluralCommandInterceptor implements IMessageInterceptor {
+    async execute(ctx: MessageInterceptorContext): Promise<MessageInterceptResult> {
+        let result = new MessageInterceptResult();
+        result.cancel = false;
+        result.message = ctx.message;
+
+        if(ctx.message.content?.toLowerCase().startsWith("p;")) {
+            console.log("[PluralCommandInterceptor] Plural command prefix detected, cancelling message send. Content: ", ctx.message.content)
+            result.cancel = true;
+        }
+
+
+        if(result.cancel) {
+            /*await emitEvent({
+                event: "MESSAGE_DELETE",
+                channel_id: ctx.message.channel_id,
+                data: {
+                    id: ctx.message.id,
+                    channel_id: ctx.message.channel_id,
+                    guild_id: ctx.message.guild_id
+                },
+            } as MessageDeleteEvent);*/
+            //result.message.flags = String((BigInt(ctx.message.flags ?? "0")) | MessageTypes.);
+            // @ts-ignore
+            result.message.ephemeral = true;
+            result.message.content += ' (ephemeral?)';
+            /*await emitEvent({
+                event: "MESSAGE_CREATE",
+                //channel_id: ctx.opts.channel_id,
+                user_id: ctx.opts.author_id,
+                data: ctx.message.toJSON(),
+            } as MessageCreateEvent);*/
+        }
+
+        return result;
+    }
+
+}