"use strict";
/**
 * @module models/user
 */
 var EventEmitter = require("events").EventEmitter;
 var utils = require("../utils");

/**
 * Construct a new User. A User must have an ID and can optionally have extra
 * information associated with it.
 * @constructor
 * @param {string} userId Required. The ID of this user.
 * @prop {string} userId The ID of the user.
 * @prop {Object} info The info object supplied in the constructor.
 * @prop {string} displayName The 'displayname' of the user if known.
 * @prop {string} avatarUrl The 'avatar_url' of the user if known.
 * @prop {string} presence The presence enum if known.
 * @prop {Number} lastActiveAgo The last time the user performed some action in ms.
 * @prop {Object} events The events describing this user.
 * @prop {MatrixEvent} events.presence The m.presence event for this user.
 */
function User(userId) {
    this.userId = userId;
    this.presence = "offline";
    this.displayName = userId;
    this.avatarUrl = null;
    this.lastActiveAgo = 0;
    this.events = {
        presence: null,
        profile: null
    };
    this._updateModifiedTime();
}
utils.inherits(User, EventEmitter);

/**
 * Update this User with the given presence event. May fire "User.presence",
 * "User.avatarUrl" and/or "User.displayName" if this event updates this user's
 * properties.
 * @param {MatrixEvent} event The <code>m.presence</code> event.
 * @fires module:client~MatrixClient#event:"User.presence"
 * @fires module:client~MatrixClient#event:"User.displayName"
 * @fires module:client~MatrixClient#event:"User.avatarUrl"
 */
User.prototype.setPresenceEvent = function(event) {
    if (event.getType() !== "m.presence") {
        return;
    }
    var firstFire = this.events.presence === null;
    this.events.presence = event;

    var eventsToFire = [];
    if (event.getContent().presence !== this.presence || firstFire) {
        eventsToFire.push("User.presence");
    }
    if (event.getContent().avatar_url !== this.avatarUrl) {
        eventsToFire.push("User.avatarUrl");
    }
    if (event.getContent().displayname !== this.displayName) {
        eventsToFire.push("User.displayName");
    }

    this.presence = event.getContent().presence;
    this.displayName = event.getContent().displayname;
    this.avatarUrl = event.getContent().avatar_url;
    this.lastActiveAgo = event.getContent().last_active_ago;

    if (eventsToFire.length > 0) {
        this._updateModifiedTime();
    }

    for (var i = 0; i < eventsToFire.length; i++) {
        this.emit(eventsToFire[i], event, this);
    }
};

/**
 * Update the last modified time to the current time.
 */
User.prototype._updateModifiedTime = function() {
    this._modified = Date.now();
};

/**
 * Get the timestamp when this User was last updated. This timestamp is
 * updated when this User receives a new Presence event which has updated a
 * property on this object. It is updated <i>before</i> firing events.
 * @return {number} The timestamp
 */
User.prototype.getLastModifiedTime = function() {
    return this._modified;
};

/**
 * The User class.
 */
module.exports = User;

/**
 * Fires whenever any user's presence changes.
 * @event module:client~MatrixClient#"User.presence"
 * @param {MatrixEvent} event The matrix event which caused this event to fire.
 * @param {User} user The user whose User.presence changed.
 * @example
 * matrixClient.on("User.presence", function(event, user){
 *   var newPresence = user.presence;
 * });
 */

/**
 * Fires whenever any user's display name changes.
 * @event module:client~MatrixClient#"User.displayName"
 * @param {MatrixEvent} event The matrix event which caused this event to fire.
 * @param {User} user The user whose User.displayName changed.
 * @example
 * matrixClient.on("User.displayName", function(event, user){
 *   var newName = user.displayName;
 * });
 */

/**
 * Fires whenever any user's avatar URL changes.
 * @event module:client~MatrixClient#"User.avatarUrl"
 * @param {MatrixEvent} event The matrix event which caused this event to fire.
 * @param {User} user The user whose User.avatarUrl changed.
 * @example
 * matrixClient.on("User.avatarUrl", function(event, user){
 *   var newUrl = user.avatarUrl;
 * });
 */