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/ChannelManager.js

@@ -0,0 +1,93 @@
+'use strict';
+
+const Channel = require('../structures/Channel');
+const BaseManager = require('./BaseManager');
+const { Events } = require('../util/Constants');
+
+/**
+ * A manager of channels belonging to a client
+ */
+class ChannelManager extends BaseManager {
+  constructor(client, iterable) {
+    super(client, iterable, Channel);
+  }
+
+  /**
+  * The cache of Channels
+  * @property {Collection<Snowflake, Channel>} cache
+  * @memberof ChannelManager
+  * @instance
+  */
+
+  add(data, guild, cache = true) {
+    const existing = this.cache.get(data.id);
+    if (existing) {
+      if (existing._patch && cache) existing._patch(data);
+      if (guild) guild.channels.add(existing);
+      return existing;
+    }
+
+    const channel = Channel.create(this.client, data, guild);
+
+    if (!channel) {
+      this.client.emit(Events.DEBUG, `Failed to find guild, or unknown type for channel ${data.id} ${data.type}`);
+      return null;
+    }
+
+    if (cache) this.cache.set(channel.id, channel);
+
+    return channel;
+  }
+
+  remove(id) {
+    const channel = this.cache.get(id);
+    if (channel.guild) channel.guild.channels.cache.delete(id);
+    this.cache.delete(id);
+  }
+
+  /**
+   * Data that can be resolved to give a Channel object. This can be:
+   * * A Channel object
+   * * A Snowflake
+   * @typedef {Channel|Snowflake} ChannelResolvable
+   */
+
+  /**
+   * Resolves a ChannelResolvable to a Channel object.
+   * @method resolve
+   * @memberof ChannelManager
+   * @instance
+   * @param {ChannelResolvable} channel The channel resolvable to resolve
+   * @returns {?Channel}
+   */
+
+  /**
+   * Resolves a ChannelResolvable to a channel ID string.
+   * @method resolveID
+   * @memberof ChannelManager
+   * @instance
+   * @param {ChannelResolvable} channel The channel resolvable to resolve
+   * @returns {?Snowflake}
+   */
+
+  /**
+   * Obtains a channel from Discord, or the channel cache if it's already available.
+   * @param {Snowflake} id ID of the channel
+   * @param {boolean} [cache=true] Whether to cache the new channel object if it isn't already
+   * @returns {Promise<Channel>}
+   * @example
+   * // Fetch a channel by its id
+   * client.channels.fetch('222109930545610754')
+   *   .then(channel => console.log(channel.name))
+   *   .catch(console.error);
+   */
+  async fetch(id, cache = true) {
+    const existing = this.cache.get(id);
+    if (existing && !existing.partial) return existing;
+
+    const data = await this.client.api.channels(id).get();
+    return this.add(data, null, cache);
+  }
+}
+
+module.exports = ChannelManager;