comm.js

/**
 * Desktop <--> extension communication module
 */
ext.comm	=	{
	send: function(cmd, data, options)
	{
		options || (options = {});

		var req		=	new XMLHttpRequest();
		req.onload	=	function()
		{
			var res	=	this.responseText;
			try
			{
				var obj	=	JSON.parse(res);
			}
			catch(e)
			{
				if(options.error) options.error('comm: error parsing json: '+ res);
				return;
			}

			if(obj.error)
			{
				if(options.error) options.error(obj.error, obj.code);
			}
			else
			{
				if(options.success) options.success(obj);
			}
		};
		req.onerror	=	function()
		{
			// signal a timeout
			if(options.error) options.error(null, -1);
		};

		data	=	ext.comm.process(cmd, data);
		req.open('get', 'http://127.0.0.1:7471/'+cmd+'?data='+encodeURIComponent(data), true);
		req.send();
	},

	/**
	 * process the data we're sending. if we're doing a simple pair request,
	 * just JSON encode it.
	 *
	 * for any other outgoing request, we're going to encrypt the data via the
	 * public key the desktop app sent us.
	 */
	process: function(cmd, data)
	{
		var str	=	JSON.stringify(data);
		if(cmd == 'pair') return str;

		var key	=	ext.pairing.get_key({binary: true});
		if(!key) return false;

		data	=	tcrypt.asym.encrypt(key, str);
		return tcrypt.to_base64(data);
	}
};