refactor(helpers): separate functions into files (#667)

* refactor(helpers): separate functions into files

* idk

* idk

src/helpers/messages/edit_message.ts

@@ -0,0 +1,40 @@
+import { botID } from "../../bot.ts";
+import { RequestManager } from "../../rest/request_manager.ts";
+import { Message, structures } from "../../structures/mod.ts";
+import {
+  Errors,
+  MessageContent,
+  MessageCreateOptions,
+  Permission,
+} from "../../types/mod.ts";
+import { endpoints } from "../../util/constants.ts";
+import { requireBotChannelPermissions } from "../../util/permissions.ts";
+
+/** Edit the message. */
+export async function editMessage(
+  message: Message,
+  content: string | MessageContent,
+) {
+  if (message.author.id !== botID) {
+    throw "You can only edit a message that was sent by the bot.";
+  }
+
+  if (typeof content === "string") content = { content };
+
+  const requiredPerms: Permission[] = ["SEND_MESSAGES"];
+
+  if (content.tts) requiredPerms.push("SEND_TTS_MESSAGES");
+
+  await requireBotChannelPermissions(message.channelID, requiredPerms);
+
+  if (content.content && content.content.length > 2000) {
+    throw new Error(Errors.MESSAGE_MAX_LENGTH);
+  }
+
+  const result = await RequestManager.patch(
+    endpoints.CHANNEL_MESSAGE(message.channelID, message.id),
+    content,
+  );
+
+  return structures.createMessageStruct(result as MessageCreateOptions);
+}