node-hca/lib/Display/DisplayManager.js

Node.js client for HCA

'use strict';

var util = require('util'),
    EventEmitter = require('events').EventEmitter,
    message = require('../Messaging/message'),
    Display = require('./Display');

(function() {

    var self,
        connection,
        displayIndex = 0,
        displays = [];

    var DisplayManager = function(conn) {
        if (!conn) {
            throw Error('A Connection instance is required.');
            return;
        }

        // Superclass constructor.
        EventEmitter.call(this);

        self = this;
        connection = conn;

        this.topics = {
            displaysReceived: 'Displays:Received',
            displayUpdated: 'Display:Updated',
            displayUpdatedId: 'Display:Updated:{id}'
        };
    };

    util.inherits(DisplayManager, EventEmitter);

    DisplayManager.prototype.init = function() {
        // Reset initial values in case of a reconnect.
        displayIndex = 0;
        displays.length = 0;

        // Remove event listeners
        connection.removeListener(connection.topics.messageReceived, onMessageReceived);
        
        var params = ['HCAApp', 'GetDisplays', '0'];

        connection.on('GetDisplays', onChunk);
        connection.send(params);
    };

    DisplayManager.prototype.getDisplayCount = function() {
        return displays.length;
    };

    DisplayManager.prototype.getDisplay = function(displayId) {
        var display = displays.filter(function(obj) {
            return obj.id == parseInt(displayId);
        });

        return display[0];
    };

    DisplayManager.prototype.getDisplays = function() {
        return displays;
    };

    var onChunk = function(response) {
        if (response.code == -1) { // end of displays.
            connection.removeListener('GetDisplays', onChunk);
            connection.on(connection.topics.messageReceived, onMessageReceived);
            self.emit(self.topics.displaysReceived, null);

            return;
        }

        decodeData(response.data);
    };

    var onMessageReceived = function(response) {
        if (response.command !== 'Update')
            return;

        updateItem(response);
    };

    var decodeData = function(data) {
        var displays = message.decode(data[0]);

        for (var i = 0; i < displays.length; i++) {
            var itemParams = message.decode(displays[i]);
            var existingItem = self.getDisplay(itemParams[0]);

            // Do not allow duplicate entries.
            if (existingItem)
                continue;

            addDisplay(itemParams);
        }

        displayIndex++;

        // Get next chunk.
        var params = ['HCAApp', 'GetDisplays', displayIndex.toString()];

        connection.send(params);
    };

    var addDisplay = function(itemParams) {
        var display = new Display();

        display.displayName = itemParams[0];
        display.id = parseInt(itemParams[1]);
        display.currentState = parseInt(itemParams[2]);
        display.iconName = itemParams[3];
        display.shortTapAction = parseInt(itemParams[4]);
        display.longTapAction = parseInt(itemParams[5]);
        display.noShow = parseInt(itemParams[6]);
        display.displayNameFormat = parseInt(itemParams[7]);
        display.currentIconName = itemParams[8];
        display.currentIconLabel = itemParams[9];
        display.displayType = parseInt(itemParams[10]);
        display.displayNameFormatLegacy = parseInt(itemParams[11]);
        display.itemIds = itemParams[12];
        display.iconRepresentation = parseInt(itemParams[13]);

        // These parameters don't appear be available. 
        display.backgroundType = parseInt(itemParams[14]);
        display.backgroundPath = itemParams[15];
        display.noAutoClose = parseInt(itemParams[16]);
        display.displayLabelName = itemParams[17];
        display.htmlPath = itemParams[18];
        display.htmlUrl = itemParams[19];
        display.themeName = itemParams[20];
        display.objectType = parseInt(itemParams[21]);
        display.alexaName = itemParams[22];

        displays.push(display);

        return display;
    };

    var updateItem = function(response) {
        var data = response.data,
            id = parseInt(data[0]),
            display = self.getDisplay(id);

        if (!(display instanceof Display))
            return;

        // TODO: Update other properties.
        // Ex: 11 Jan 15:06:35 - [RCV] {"code":"0","group":"HCAApp","command":"Update","data":["5021","0","0","0","","","100","20160111150634"]}

        display.currentState = parseInt(data[1]);
        // display.suspend = parseInt(data[2]);
        // display.buttonState = data[3];
        // display.iconName = data[4];
        // display.iconLabel = data[5];
        // display.currentIconRepresentation = parseInt(data[6]);

        self.emit(self.topics.displayUpdated);
        self.emit(self.topics.displayUpdated + ':' + id, display); // Emit with id of updated item.
    };

    module.exports = DisplayManager;

})();