discord.js/src/structures/GuildChannel.js

const Channel = require('./Channel');
const Role = require('./Role');
const Invite = require('./Invite');
const PermissionOverwrites = require('./PermissionOverwrites');
const Util = require('../util/Util');
const Permissions = require('../util/Permissions');
const Collection = require('../util/Collection');
const Constants = require('../util/Constants');
const { TypeError } = require('../errors');

/**
 * Represents a guild channel (e.g. text channels and voice channels).
 * @extends {Channel}
 */
class GuildChannel extends Channel {
  constructor(guild, data) {
    super(guild.client, data);

    /**
     * The guild the channel is in
     * @type {Guild}
     */
    this.guild = guild;
  }

  _patch(data) {
    super._patch(data);

    /**
     * The name of the guild channel
     * @type {string}
     */
    this.name = data.name;

    /**
     * The raw position of the channel from discord
     * @type {number}
     */
    this.rawPosition = data.position;

    /**
     * The ID of the category parent of this channel
     * @type {?Snowflake}
     */
    this.parentID = data.parent_id;

    /**
     * A map of permission overwrites in this channel for roles and users
     * @type {Collection<Snowflake, PermissionOverwrites>}
     */
    this.permissionOverwrites = new Collection();
    if (data.permission_overwrites) {
      for (const overwrite of data.permission_overwrites) {
        this.permissionOverwrites.set(overwrite.id, new PermissionOverwrites(this, overwrite));
      }
    }
  }

  /**
   * The category parent of this channel
   * @type {?CategoryChannel}
   * @readonly
   */
  get parent() {
    return this.guild.channels.get(this.parentID);
  }

  /**
   * The position of the channel
   * @type {number}
   * @readonly
   */
  get position() {
    const sorted = this.guild._sortedChannels(this);
    return sorted.array().indexOf(sorted.get(this.id));
  }

  /**
   * Gets the overall set of permissions for a user in this channel, taking into account roles and permission
   * overwrites.
   * @param {GuildMemberResolvable} member The user that you want to obtain the overall permissions for
   * @returns {?Permissions}
   */
  permissionsFor(member) {
    member = this.guild.members.resolve(member);
    if (!member) return null;
    if (member.id === this.guild.ownerID) return new Permissions(Permissions.ALL).freeze();

    const roles = member.roles;
    const permissions = new Permissions(roles.map(role => role.permissions));

    if (permissions.has(Permissions.FLAGS.ADMINISTRATOR)) return new Permissions(Permissions.ALL).freeze();

    const overwrites = this.overwritesFor(member, true, roles);

    return permissions
      .remove(overwrites.everyone ? overwrites.everyone.denied : 0)
      .add(overwrites.everyone ? overwrites.everyone.allowed : 0)
      .remove(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.denied) : 0)
      .add(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.allowed) : 0)
      .remove(overwrites.member ? overwrites.member.denied : 0)
      .add(overwrites.member ? overwrites.member.allowed : 0)
      .freeze();
  }

  overwritesFor(member, verified = false, roles = null) {
    if (!verified) member = this.guild.members.resolve(member);
    if (!member) return [];

    roles = roles || member.roles;
    const roleOverwrites = [];
    let memberOverwrites;
    let everyoneOverwrites;

    for (const overwrite of this.permissionOverwrites.values()) {
      if (overwrite.id === this.guild.id) {
        everyoneOverwrites = overwrite;
      } else if (roles.has(overwrite.id)) {
        roleOverwrites.push(overwrite);
      } else if (overwrite.id === member.id) {
        memberOverwrites = overwrite;
      }
    }

    return {
      everyone: everyoneOverwrites,
      roles: roleOverwrites,
      member: memberOverwrites,
    };
  }

  /**
   * An object mapping permission flags to `true` (enabled), `null` (default) or `false` (disabled).
   * ```js
   * {
   *  'SEND_MESSAGES': true,
   *  'EMBED_LINKS': null,
   *  'ATTACH_FILES': false,
   * }
   * ```
   * @typedef {Object} PermissionOverwriteOptions
   */

  /**
   * Overwrites the permissions for a user or role in this channel.
   * @param {RoleResolvable|UserResolvable} userOrRole The user or role to update
   * @param {PermissionOverwriteOptions} options The configuration for the update
   * @param {string} [reason] Reason for creating/editing this overwrite
   * @returns {Promise<GuildChannel>}
   * @example
   * // Overwrite permissions for a message author
   * message.channel.overwritePermissions(message.author, {
   *   SEND_MESSAGES: false
   * })
   *   .then(() => console.log('Done!'))
   *   .catch(console.error);
   */
  overwritePermissions(userOrRole, options, reason) {
    const allow = new Permissions(0);
    const deny = new Permissions(0);
    let type;

    const role = this.guild.roles.get(userOrRole);

    if (role || userOrRole instanceof Role) {
      userOrRole = role || userOrRole;
      type = 'role';
    } else {
      userOrRole = this.client.users.resolve(userOrRole);
      type = 'member';
      if (!userOrRole) return Promise.reject(new TypeError('INVALID_TYPE', 'parameter', 'User nor a Role', true));
    }

    const prevOverwrite = this.permissionOverwrites.get(userOrRole.id);

    if (prevOverwrite) {
      allow.add(prevOverwrite.allowed);
      deny.add(prevOverwrite.denied);
    }

    for (const perm in options) {
      if (options[perm] === true) {
        allow.add(Permissions.FLAGS[perm] || 0);
        deny.remove(Permissions.FLAGS[perm] || 0);
      } else if (options[perm] === false) {
        allow.remove(Permissions.FLAGS[perm] || 0);
        deny.add(Permissions.FLAGS[perm] || 0);
      } else if (options[perm] === null) {
        allow.remove(Permissions.FLAGS[perm] || 0);
        deny.remove(Permissions.FLAGS[perm] || 0);
      }
    }

    return this.client.api.channels(this.id).permissions[userOrRole.id]
      .put({ data: { id: userOrRole.id, type, allow: allow.bitfield, deny: deny.bitfield }, reason })
      .then(() => this);
  }

  /**
   * A collection of members that can see this channel, mapped by their ID
   * @type {Collection<Snowflake, GuildMember>}
   * @readonly
   */
  get members() {
    const members = new Collection();
    for (const member of this.guild.members.values()) {
      if (this.permissionsFor(member).has('VIEW_CHANNEL')) {
        members.set(member.id, member);
      }
    }
    return members;
  }

  /**
   * The data for a guild channel.
   * @typedef {Object} ChannelData
   * @property {string} [name] The name of the channel
   * @property {number} [position] The position of the channel
   * @property {string} [topic] The topic of the text channel
   * @property {number} [bitrate] The bitrate of the voice channel
   * @property {number} [userLimit] The user limit of the voice channel
   * @property {Snowflake} [parentID] The parent ID of the channel
   * @property {boolean} [lockPermissions] Lock the permissions of the channel to what the parent's permissions are
   */

  /**
   * Edits the channel.
   * @param {ChannelData} data The new data for the channel
   * @param {string} [reason] Reason for editing this channel
   * @returns {Promise<GuildChannel>}
   * @example
   * // Edit a channel
   * channel.edit({name: 'new-channel'})
   *   .then(c => console.log(`Edited channel ${c}`))
   *   .catch(console.error);
   */
  edit(data, reason) {
    return this.client.api.channels(this.id).patch({
      data: {
        name: (data.name || this.name).trim(),
        topic: data.topic,
        position: data.position || this.position,
        bitrate: data.bitrate || (this.bitrate ? this.bitrate * 1000 : undefined),
        user_limit: data.userLimit != null ? data.userLimit : this.userLimit, // eslint-disable-line eqeqeq
        parent_id: data.parentID,
        lock_permissions: data.lockPermissions,
      },
      reason,
    }).then(newData => {
      const clone = this._clone();
      clone._patch(newData);
      return clone;
    });
  }

  /**
   * Set a new name for the guild channel.
   * @param {string} name The new name for the guild channel
   * @param {string} [reason] Reason for changing the guild channel's name
   * @returns {Promise<GuildChannel>}
   * @example
   * // Set a new channel name
   * channel.setName('not_general')
   *   .then(newChannel => console.log(`Channel's new name is ${newChannel.name}`))
   *   .catch(console.error);
   */
  setName(name, reason) {
    return this.edit({ name }, reason);
  }

  /**
   * Set a new position for the guild channel.
   * @param {number} position The new position for the guild channel
   * @param {boolean} [relative=false] Move the position relative to its current value
   * @returns {Promise<GuildChannel>}
   * @example
   * // Set a new channel position
   * channel.setPosition(2)
   *   .then(newChannel => console.log(`Channel's new position is ${newChannel.position}`))
   *   .catch(console.error);
   */
  setPosition(position, { relative, reason }) {
    position = Number(position);
    if (isNaN(position)) return Promise.reject(new TypeError('INVALID_TYPE', 'position', 'number'));
    let updatedChannels = this.guild._sortedChannels(this).array();
    Util.moveElementInArray(updatedChannels, this, position, relative);
    updatedChannels = updatedChannels.map((r, i) => ({ id: r.id, position: i }));
    return this.client.api.guilds(this.id).channels.patch({ data: updatedChannels, reason })
      .then(() => {
        this.client.actions.GuildChannelsPositionUpdate.handle({
          guild_id: this.id,
          channels: updatedChannels,
        });
        return this;
      });
  }

  /**
   * Set the category parent of this channel.
   * @param {GuildChannel|Snowflake} channel Parent channel
   * @param {boolean} [options.lockPermissions] Lock the permissions to what the parent's permissions are
   * @param {string} [options.reason] Reason for modifying the parent of this channel
   * @returns {Promise<GuildChannel>}
   */
  setParent(channel, { lockPermissions = true, reason } = {}) {
    return this.edit({
      parentID: channel.id ? channel.id : channel,
      lockPermissions,
    }, reason);
  }

  /**
   * Set a new topic for the guild channel.
   * @param {string} topic The new topic for the guild channel
   * @param {string} [reason] Reason for changing the guild channel's topic
   * @returns {Promise<GuildChannel>}
   * @example
   * // Set a new channel topic
   * channel.setTopic('needs more rate limiting')
   *   .then(newChannel => console.log(`Channel's new topic is ${newChannel.topic}`))
   *   .catch(console.error);
   */
  setTopic(topic, reason) {
    return this.edit({ topic }, reason);
  }

  /**
   * Create an invite to this guild channel.
   * @param {Object} [options={}] Options for the invite
   * @param {boolean} [options.temporary=false] Whether members that joined via the invite should be automatically
   * kicked after 24 hours if they have not yet received a role
   * @param {number} [options.maxAge=86400] How long the invite should last (in seconds, 0 for forever)
   * @param {number} [options.maxUses=0] Maximum number of uses
   * @param {boolean} [options.unique=false] Create a unique invite, or use an existing one with similar settings
   * @param {string} [options.reason] Reason for creating this
   * @returns {Promise<Invite>}
   */
  createInvite({ temporary = false, maxAge = 86400, maxUses = 0, unique, reason } = {}) {
    return this.client.api.channels(this.id).invites.post({ data: {
      temporary, max_age: maxAge, max_uses: maxUses, unique,
    }, reason })
      .then(invite => new Invite(this.client, invite));
  }

  /**
   * Clone this channel.
   * @param {Object} [options] The options
   * @param {string} [options.name=this.name] Optional name for the new channel, otherwise it has the name
   * of this channel
   * @param {boolean} [options.withPermissions=true] Whether to clone the channel with this channel's
   * permission overwrites
   * @param {boolean} [options.withTopic=true] Whether to clone the channel with this channel's topic
   * @param {string} [options.reason] Reason for cloning this channel
   * @returns {Promise<GuildChannel>}
   */
  clone({ name = this.name, withPermissions = true, withTopic = true, reason } = {}) {
    const options = { overwrites: withPermissions ? this.permissionOverwrites : [], reason };
    return this.guild.createChannel(name, this.type, options)
      .then(channel => withTopic ? channel.setTopic(this.topic) : channel);
  }

  /**
   * Checks if this channel has the same type, topic, position, name, overwrites and ID as another channel.
   * In most cases, a simple `channel.id === channel2.id` will do, and is much faster too.
   * @param {GuildChannel} channel Channel to compare with
   * @returns {boolean}
   */
  equals(channel) {
    let equal = channel &&
      this.id === channel.id &&
      this.type === channel.type &&
      this.topic === channel.topic &&
      this.position === channel.position &&
      this.name === channel.name;

    if (equal) {
      if (this.permissionOverwrites && channel.permissionOverwrites) {
        equal = this.permissionOverwrites.equals(channel.permissionOverwrites);
      } else {
        equal = !this.permissionOverwrites && !channel.permissionOverwrites;
      }
    }

    return equal;
  }

  /**
   * Whether the channel is deletable by the client user
   * @type {boolean}
   * @readonly
   */
  get deletable() {
    return this.id !== this.guild.id &&
      this.permissionsFor(this.client.user).has(Permissions.FLAGS.MANAGE_CHANNELS);
  }

  /**
   * Deletes this channel.
   * @param {string} [reason] Reason for deleting this channel
   * @returns {Promise<GuildChannel>}
   * @example
   * // Delete the channel
   * channel.delete('making room for new channels')
   *   .then() // Success
   *   .catch(console.error); // Log error
   */
  delete(reason) {
    return this.client.api.channels(this.id).delete({ reason }).then(() => this);
  }

  /**
   * Whether the channel is muted
   * <warn>This is only available when using a user account.</warn>
   * @type {?boolean}
   * @readonly
   */
  get muted() {
    if (this.client.user.bot) return null;
    try {
      return this.client.user.guildSettings.get(this.guild.id).channelOverrides.get(this.id).muted;
    } catch (err) {
      return false;
    }
  }

  /**
   * The type of message that should notify you
   * one of `EVERYTHING`, `MENTIONS`, `NOTHING`, `INHERIT`
   * <warn>This is only available when using a user account.</warn>
   * @type {?string}
   * @readonly
   */
  get messageNotifications() {
    if (this.client.user.bot) return null;
    try {
      return this.client.user.guildSettings.get(this.guild.id).channelOverrides.get(this.id).messageNotifications;
    } catch (err) {
      return Constants.MessageNotificationTypes[3];
    }
  }

  /**
   * When concatenated with a string, this automatically returns the channel's mention instead of the Channel object.
   * @returns {string}
   * @example
   * // Outputs: Hello from #general
   * console.log(`Hello from ${channel}`);
   * @example
   * // Outputs: Hello from #general
   * console.log('Hello from ' + channel);
   */
  toString() {
    return `<#${this.id}>`;
  }
}

module.exports = GuildChannel;