feat: remove datastores and implement Managers (#3696)

* Initial commit: add 5 initial managers

- Base manager
- GuildChannelManager
- MessageManager
- PresenceManager
- Reaction Manager
- Added LimitedCollection

* Add GuildEmojiManager, various fixes

* Modify some managers and add guildmembermanager

* Initial integration

* Delete old stores

* Integration part two, removed LRUCollection

- Most of the integration has been finished
- TODO typings
- Removed LRUCollection, needless sweeping

* Typings + stuff i somehow missed in ChannelManager

* LimitedCollection typings/ final changes

* Various jsdoc and syntactical fixes, Removed Util.mixin()

* tslint fix

* Grammatical and logical changes

* Delete temporary file placed by mistake

* Grammatical changes

* Add missing type

* Update jsdoc examples

* fix: ChannelManager#remove should call cache#delete not cache#remove

* fix recursive require

* Fix missed cache in util

* fix: more missed cache

* Remove accidental _fetchMany change from #3645

* fix: use .cache.delete() over .remove()

* fix: missing cache in ReactionCollector

* fix: missed cache in client

* fix: members is a collection not a manager

Co-Authored-By: Sugden <28943913+NotSugden@users.noreply.github.com>

* fix: various docs and cache fixes

* fix: missed cache

* fix: missing _roles

* Final testing and debugging

* LimitedCollection: return the Collection instead of undefined on .set

* Add cache to BaseManager in typings

* Commit fixes i forgot to stage yesterday

* Update invite events

* Account for new commit

* fix: MessageReactionRemoveAll should call .cache.clear()

* fix: add .cache at various places, correct return type

* docs: remove mentions of 'store'

* Add extra documented properties to typings

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>
Co-authored-by: SpaceEEC <spaceeec@yahoo.com>

src/managers/ReactionUserManager.js

@@ -0,0 +1,66 @@
+'use strict';
+
+const Collection = require('../util/Collection');
+const BaseManager = require('./BaseManager');
+const { Error } = require('../errors');
+
+/**
+ * Manages API methods for users who reacted to a reaction and stores their cache.
+ * @extends {BaseManager}
+ */
+class ReactionUserManager extends BaseManager {
+  constructor(client, iterable, reaction) {
+    super(client, iterable, { name: 'User' });
+    /**
+     * The reaction that this manager belongs to
+     * @type {MessageReaction}
+     */
+    this.reaction = reaction;
+  }
+
+  /**
+   * The cache of this manager
+   * @property {Collection<Snowflake, User>} cache
+   * @memberof GuildManager
+   * @instance
+   */
+
+  /**
+   * Fetches all the users that gave this reaction. Resolves with a collection of users, mapped by their IDs.
+   * @param {Object} [options] Options for fetching the users
+   * @param {number} [options.limit=100] The maximum amount of users to fetch, defaults to 100
+   * @param {Snowflake} [options.before] Limit fetching users to those with an id lower than the supplied id
+   * @param {Snowflake} [options.after] Limit fetching users to those with an id greater than the supplied id
+   * @returns {Promise<Collection<Snowflake, User>>}
+   */
+  async fetch({ limit = 100, after, before } = {}) {
+    const message = this.reaction.message;
+    const data = await this.client.api.channels[message.channel.id].messages[message.id]
+      .reactions[this.reaction.emoji.identifier]
+      .get({ query: { limit, before, after } });
+    const users = new Collection();
+    for (const rawUser of data) {
+      const user = this.client.users.add(rawUser);
+      this.cache.set(user.id, user);
+      users.set(user.id, user);
+    }
+    return users;
+  }
+
+  /**
+   * Removes a user from this reaction.
+   * @param {UserResolvable} [user=this.reaction.message.client.user] The user to remove the reaction of
+   * @returns {Promise<MessageReaction>}
+   */
+  remove(user = this.reaction.message.client.user) {
+    const message = this.reaction.message;
+    const userID = message.client.users.resolveID(user);
+    if (!userID) return Promise.reject(new Error('REACTION_RESOLVE_USER'));
+    return message.client.api.channels[message.channel.id].messages[message.id]
+      .reactions[this.reaction.emoji.identifier][userID === message.client.user.id ? '@me' : userID]
+      .delete()
+      .then(() => this.reaction);
+  }
+}
+
+module.exports = ReactionUserManager;