add lots of group dm features (#1208)

* group dm stuff

* minor doc changes

src/client/rest/RESTMethods.js

@@ -14,6 +14,7 @@ const Webhook = require('../../structures/Webhook');
 const UserProfile = require('../../structures/UserProfile');
 const OAuth2Application = require('../../structures/OAuth2Application');
 const Channel = require('../../structures/Channel');
+const GroupDMChannel = require('../../structures/GroupDMChannel');
 const Guild = require('../../structures/Guild');
 const VoiceRegion = require('../../structures/VoiceRegion');
 
@@ -246,6 +247,23 @@ class RESTMethods {
     }).then(data => this.client.actions.ChannelCreate.handle(data).channel);
   }
 
+  createGroupDM(options) {
+    const data = this.client.user.bot ?
+      { access_tokens: options.accessTokens, nicks: options.nicks } :
+      { recipients: options.recipients };
+
+    return this.rest.makeRequest('post', Constants.Endpoints.meChannels, true, data)
+    .then(res => new GroupDMChannel(this.client, res));
+  }
+
+  addUserToGroupDM(channel, options) {
+    const data = this.client.user.bot ?
+      { nick: options.nick, access_token: options.accessToken } :
+      { recipient: options.id };
+    return this.rest.makeRequest('put', Constants.Endpoints.dmChannelRecipient(channel.id, options.id), true, data)
+    .then(() => channel);
+  }
+
   getExistingDM(recipient) {
     return this.client.channels.find(channel =>
       channel.recipient && channel.recipient.id === recipient.id

src/structures/ClientUser.js

@@ -301,6 +301,29 @@ class ClientUser extends User {
     }
   }
 
+  /**
+   * An object containing either a user or access token, and an optional nickname
+   * @typedef {Object} GroupDMRecipientOptions
+   * @property {UserResolvable|Snowflake} [user] User to add to the group dm
+   * (only available if a user is creating the dm)
+   * @property {string} [accessToken] Access token to use to add a user to the group dm
+   * (only available if a bot is creating the dm)
+   * @property {string} [nick] Permanent nickname (only available if a bot is creating the dm)
+   */
+
+  /**
+   * Create a group dm
+   * @param {GroupDMRecipientOptions[]} recipients The recipients
+   * @returns {Promise<GroupDMChannel>}
+   */
+  createGroupDM(recipients) {
+    return this.client.rest.methods.createGroupDM({
+      recipients: recipients.map(u => this.client.resolver.resolveUserID(u.user)),
+      accessTokens: recipients.map(u => u.accessToken),
+      nicks: recipients.map(u => u.nick),
+    });
+  }
+
   /**
    * @param {Invite|string} invite Invite or code to accept
    * @returns {Promise<Guild>} Joined guild

src/structures/GroupDMChannel.js

@@ -58,6 +58,24 @@ class GroupDMChannel extends Channel {
      */
     this.ownerID = data.owner_id;
 
+    /**
+     * If the dm is managed by an application
+     * @type {boolean}
+     */
+    this.managed = data.managed;
+
+    /**
+     * Application ID of the application that made this group dm, if applicable
+     * @type {?string}
+     */
+    this.applicationID = data.application_id;
+
+    /**
+     * Nicknames for group members
+     * @type {?Collection<Snowflake, String>}
+     */
+    if (data.nicks) this.nicks = new Collection(data.nicks.map(n => [n.id, n.nick]));
+
     if (!this.recipients) {
       /**
        * A collection of the recipients of this DM, mapped by their ID.
@@ -106,6 +124,20 @@ class GroupDMChannel extends Channel {
     return equal;
   }
 
+  /**
+   * Add a user to the dm
+   * @param {UserResolvable|String} accessTokenOrID Access token or user resolvable
+   * @param {string} [nick] Permanent nickname to give the user (only available if a bot is creating the dm)
+   */
+
+  addUser(accessTokenOrID, nick) {
+    return this.client.rest.methods.addUserToGroupDM(this, {
+      nick,
+      id: this.client.resolver.resolveUserID(accessTokenOrID),
+      accessToken: accessTokenOrID,
+    });
+  }
+
   /**
    * When concatenated with a string, this automatically concatenates the channel's name instead of the Channel object.
    * @returns {string}

src/util/Constants.js

@@ -103,6 +103,7 @@ const Endpoints = exports.Endpoints = {
   },
   me: `${API}/users/@me`,
   meGuild: (guildID) => `${Endpoints.me}/guilds/${guildID}`,
+  meChannels: `${API}/users/@me/channels`,
   meMentions: (limit, roles, everyone, guildID) =>
     `users/@me/mentions?limit=${limit}&roles=${roles}&everyone=${everyone}${guildID ? `&guild_id=${guildID}` : ''}`,
   relationships: (userID) => `${Endpoints.user(userID)}/relationships`,
@@ -143,6 +144,8 @@ const Endpoints = exports.Endpoints = {
   channelWebhooks: (channelID) => `${Endpoints.channel(channelID)}/webhooks`,
   channelSearch: (channelID) => `${Endpoints.channelMessages(channelID)}/search`,
 
+  dmChannelRecipient: (channelID, recipientID) => `${Endpoints.channel(channelID)}/recipients/${recipientID}`,
+
   // message reactions
   messageReactions: (channelID, messageID) => `${Endpoints.channelMessage(channelID, messageID)}/reactions`,
   messageReaction: