--[[*************************************************************************
**
** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtWebChannel module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
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**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
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***************************************************************************]]
local QtCore = require 'qtcore'
local QtWebChannel = require 'qtwebchannel'

--------------------------------------------------------------------------------
-- \brief QWebChannelAbstractSocket implementation that uses a QWebSocket internally.

-- The transport delegates all messages received over the QWebSocket over its
-- textMessageReceived signal. Analogously, all calls to sendTextMessage will
-- be send over the QWebSocket to the remote client.
--------------------------------------------------------------------------------
local Class = QtCore.Class('WebSocketTransport', QtWebChannel.QWebChannelAbstractTransport) {}

function Class:__static_init()
	self:__addslot('textMessageReceived(QString)', self.textMessageReceived, 'private')
end
--------------------------------------------------------------------------------
-- Construct the transport object and wrap the given socket.

-- The socket is also set as the parent of the transport object.
--------------------------------------------------------------------------------
function Class:__init(socket)
	self.socket = socket

	self.connect(socket, SIGNAL 'textMessageReceived(QString)', self, SLOT 'textMessageReceived(QString)')
	self.connect(socket, SIGNAL 'disconnected()', self, SLOT 'deleteLater()')
end
--------------------------------------------------------------------------------
-- Destroys the WebSocketTransport.
--------------------------------------------------------------------------------
function Class:__uninit()
	self.socket:deleteLater()
end
--------------------------------------------------------------------------------
-- Serialize the JSON message and send it as a text message via the WebSocket to the client.
--------------------------------------------------------------------------------
function Class:sendMessage(message)
	local doc = QtCore.QJsonDocument(message)
	self.socket:sendTextMessage(QtCore.QString.fromUtf8(doc:toJson('Compact')))
end
--------------------------------------------------------------------------------
-- Deserialize the stringified JSON messageData and emit messageReceived.
--------------------------------------------------------------------------------
function Class:textMessageReceived(messageData)
	local error = QtCore.QJsonParseError()
	local message = QtCore.QJsonDocument.fromJson(messageData:toUtf8(), error)
	if error.error ~= 'NoError' then
		qWarning():IN('Failed to parse text message as JSON object:'):IN(messageData)
			:IN('Error is:'):IN(error:errorString())
		return
	elseif not message:isObject() then
		qWarning():IN('Received JSON message that is not an object: '):IN(messageData)
		return
	end
	local obj = message:object()
	self:__emit('messageReceived', obj, { 'QWebChannelAbstractTransport*', self })
end

return Class
