add webhook functionality

src/handlers/webhook.ts

@@ -0,0 +1,102 @@
+import {
+  WebhookCreateOptions,
+  WebhookPayload,
+  ExecuteWebhookOptions,
+} from "../types/webhook.ts";
+import { botHasChannelPermissions } from "../utils/permissions.ts";
+import { Permissions } from "../types/permission.ts";
+import { Errors } from "../types/errors.ts";
+import { RequestManager } from "../module/requestManager.ts";
+import { endpoints } from "../constants/discord.ts";
+import { createMessage } from "../structures/message.ts";
+import { MessageCreateOptions } from "../types/message.ts";
+import { urlToBase64 } from "../utils/utils.ts";
+
+/** Create a new webhook. Requires the MANAGE_WEBHOOKS permission. Returns a webhook object on success. Webhook names follow our naming restrictions that can be found in our Usernames and Nicknames documentation, with the following additional stipulations:
+*
+* Webhook names cannot be: 'clyde'
+*/
+export async function createWebhook(
+  channelID: string,
+  options: WebhookCreateOptions,
+) {
+  if (
+    !botHasChannelPermissions(
+      channelID,
+      [Permissions.MANAGE_WEBHOOKS],
+    )
+  ) {
+    throw new Error(Errors.MISSING_MANAGE_WEBHOOKS);
+  }
+
+  if (
+    // Specific usernames that discord does not allow
+    options.name === "clyde" ||
+    // Character limit checks. [...] checks are because of js unicode length handling
+    [...options.name].length < 2 || [...options.name].length > 32
+  ) {
+    throw new Error(Errors.INVALID_WEBHOOK_NAME);
+  }
+
+  return RequestManager.post(
+    endpoints.CHANNEL_WEBHOOKS(channelID),
+    {
+      ...options,
+      avatar: options.avatar ? await urlToBase64(options.avatar) : undefined,
+    },
+  ) as Promise<WebhookPayload>;
+}
+
+export async function executeWebhook(
+  webhookID: string,
+  webhookToken: string,
+  options: ExecuteWebhookOptions,
+) {
+  if (!options.content && !options.file && !options.embeds) {
+    throw new Error(Errors.INVALID_WEBHOOK_OPTIONS);
+  }
+
+  if (options.embeds && options.embeds.length > 10) {
+    options.embeds.splice(10);
+  }
+
+  if (options.mentions) {
+    if (options.mentions.users?.length) {
+      if (options.mentions.parse.includes("users")) {
+        options.mentions.parse = options.mentions.parse.filter((p) =>
+          p !== "users"
+        );
+      }
+
+      if (options.mentions.users.length > 100) {
+        options.mentions.users = options.mentions.users.slice(0, 100);
+      }
+    }
+
+    if (options.mentions.roles?.length) {
+      if (options.mentions.parse.includes("roles")) {
+        options.mentions.parse = options.mentions.parse.filter((p) =>
+          p !== "roles"
+        );
+      }
+
+      if (options.mentions.roles.length > 100) {
+        options.mentions.roles = options.mentions.roles.slice(0, 100);
+      }
+    }
+  }
+
+  const result = await RequestManager.post(
+    `${endpoints.WEBHOOK(webhookID, webhookToken)}${
+      options.wait ? "?wait=true" : ""
+    }`,
+    {
+      ...options,
+      allowed_mentions: options.mentions,
+      avatar_url: options.avatar_url,
+    },
+  );
+  if (!options.wait) return;
+
+  return createMessage(result as MessageCreateOptions);
+}