1 files changed, 136 insertions, 0 deletions
diff --git a/api/src/util/Message.ts b/api/src/util/Message.ts
new file mode 100644
index 00000000..e811f522
--- /dev/null
+++ b/api/src/util/Message.ts
@@ -0,0 +1,136 @@
+import { ChannelModel, Embed, Message, MessageCreateEvent, MessageUpdateEvent } from "@fosscord/server-util";
+import { Snowflake } from "@fosscord/server-util";
+import { MessageModel } from "@fosscord/server-util";
+import { PublicMemberProjection } from "@fosscord/server-util";
+import { toObject } from "@fosscord/server-util";
+import { getPermission } from "@fosscord/server-util";
+import { HTTPError } from "lambert-server";
+import fetch from "node-fetch";
+import cheerio from "cheerio";
+import { emitEvent } from "./Event";
+import { MessageType } from "@fosscord/server-util/dist/util/Constants";
+// TODO: check webhook, application, system author
+
+const LINK_REGEX = /https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)/g;
+
+const DEFAULT_FETCH_OPTIONS: any = {
+	redirect: "follow",
+	follow: 1,
+	headers: {
+		"user-agent": "Mozilla/5.0 (compatible; Discordbot/2.0; +https://discordapp.com)"
+	},
+	size: 1024 * 1024 * 1,
+	compress: true,
+	method: "GET"
+};
+
+export async function handleMessage(opts: Partial<Message>) {
+	const channel = await ChannelModel.findOne(
+		{ id: opts.channel_id },
+		{ guild_id: true, type: true, permission_overwrites: true, recipient_ids: true, owner_id: true }
+	)
+		.lean() // lean is needed, because we don't want to populate .recipients that also auto deletes .recipient_ids
+		.exec();
+	if (!channel || !opts.channel_id) throw new HTTPError("Channel not found", 404);
+	// TODO: are tts messages allowed in dm channels? should permission be checked?
+
+	// @ts-ignore
+	const permissions = await getPermission(opts.author_id, channel.guild_id, opts.channel_id, { channel });
+	permissions.hasThrow("SEND_MESSAGES");
+	if (opts.tts) permissions.hasThrow("SEND_TTS_MESSAGES");
+	if (opts.message_reference) {
+		permissions.hasThrow("READ_MESSAGE_HISTORY");
+		if (opts.message_reference.guild_id !== channel.guild_id) throw new HTTPError("You can only reference messages from this guild");
+		if (opts.message_reference.channel_id !== opts.channel_id) throw new HTTPError("You can only reference messages from this channel");
+		// TODO: should be checked if the referenced message exists?
+		// @ts-ignore
+		opts.type = MessageType.REPLY;
+	}
+
+	if (!opts.content && !opts.embeds?.length && !opts.attachments?.length && !opts.stickers?.length && !opts.activity) {
+		throw new HTTPError("Empty messages are not allowed", 50006);
+	}
+
+	// TODO: check and put it all in the body
+	return {
+		...opts,
+		guild_id: channel.guild_id,
+		channel_id: opts.channel_id,
+		// TODO: generate mentions and check permissions
+		mention_channels_ids: [],
+		mention_role_ids: [],
+		mention_user_ids: [],
+		attachments: opts.attachments || [], // TODO: message attachments
+		embeds: opts.embeds || [],
+		reactions: opts.reactions || [],
+		type: opts.type ?? 0
+	};
+}
+
+// TODO: cache link result in db
+export async function postHandleMessage(message: Message) {
+	var links = message.content?.match(LINK_REGEX);
+	if (!links) return;
+
+	const data = { ...message };
+	data.embeds = data.embeds.filter((x) => x.type !== "link");
+
+	links = links.slice(0, 5); // embed max 5 links
+
+	for (const link of links) {
+		try {
+			const request = await fetch(link, DEFAULT_FETCH_OPTIONS);
+
+			const text = await request.text();
+			const $ = cheerio.load(text);
+
+			const title = $('meta[property="og:title"]').attr("content");
+			const provider_name = $('meta[property="og:site_name"]').text();
+			const author_name = $('meta[property="article:author"]').attr("content");
+			const description = $('meta[property="og:description"]').attr("content") || $('meta[property="description"]').attr("content");
+			const image = $('meta[property="og:image"]').attr("content");
+			const url = $('meta[property="og:url"]').attr("content");
+			// TODO: color
+			const embed: Embed = {
+				provider: {
+					url: link,
+					name: provider_name
+				}
+			};
+
+			if (author_name) embed.author = { name: author_name };
+			if (image) embed.thumbnail = { proxy_url: image, url: image };
+			if (title) embed.title = title;
+			if (url) embed.url = url;
+			if (description) embed.description = description;
+
+			if (title || description) {
+				data.embeds.push(embed);
+			}
+		} catch (error) {}
+	}
+
+	await Promise.all([
+		emitEvent({
+			event: "MESSAGE_UPDATE",
+			guild_id: message.guild_id,
+			channel_id: message.channel_id,
+			data
+		} as MessageUpdateEvent),
+		MessageModel.updateOne({ id: message.id, channel_id: message.channel_id }, data).exec()
+	]);
+}
+
+export async function sendMessage(opts: Partial<Message>) {
+	const message = await handleMessage({ ...opts, id: Snowflake.generate(), timestamp: new Date() });
+
+	const data = toObject(
+		await new MessageModel(message).populate({ path: "member", select: PublicMemberProjection }).populate("referenced_message").save()
+	);
+
+	await emitEvent({ event: "MESSAGE_CREATE", channel_id: opts.channel_id, data, guild_id: message.guild_id } as MessageCreateEvent);
+
+	postHandleMessage(data).catch((e) => {}); // no await as it shouldnt block the message send function and silently catch error
+
+	return data;
+}