#!/usr/bin/env python

############################################################################
# 
#  Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
# 
#  This file is part of the example classes of the Qt Toolkit.
# 
#  This file may be used under the terms of the GNU General Public
#  License version 2.0 as published by the Free Software Foundation
#  and appearing in the file LICENSE.GPL included in the packaging of
#  self file.  Please review the following information to ensure GNU
#  General Public Licensing requirements will be met:
#  http://www.trolltech.com/products/qt/opensource.html
# 
#  If you are unsure which license is appropriate for your use, please
#  review the following information:
#  http://www.trolltech.com/products/qt/licensing.html or contact the
#  sales department at sales@trolltech.com.
# 
#  This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
#  WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
# 
############################################################################

from PyQt4 import QtCore, QtGui, QtNetwork


class Dialog(QtGui.QDialog):
    TotalBytes = 50 * 1024 * 1024
    PayloadSize = 65536

    def __init__(self, parent=None):
        super(Dialog, self).__init__(parent)

        self.tcpServer = QtNetwork.QTcpServer()
        self.tcpClient = QtNetwork.QTcpSocket()
        self.bytesToWrite = 0
        self.bytesWritten = 0
        self.bytesReceived = 0

        self.clientProgressBar = QtGui.QProgressBar()
        self.clientStatusLabel = QtGui.QLabel("Client ready")
        self.serverProgressBar = QtGui.QProgressBar()
        self.serverStatusLabel = QtGui.QLabel("Server ready")

        self.startButton = QtGui.QPushButton("&Start")
        self.quitButton = QtGui.QPushButton("&Quit")

        buttonBox = QtGui.QDialogButtonBox()
        buttonBox.addButton(self.startButton, QtGui.QDialogButtonBox.ActionRole)
        buttonBox.addButton(self.quitButton, QtGui.QDialogButtonBox.RejectRole)

        self.startButton.clicked.connect(self.start)
        self.quitButton.clicked.connect(self.close)
        self.tcpServer.newConnection.connect(self.acceptConnection)
        self.tcpClient.connected.connect(self.startTransfer)
        self.tcpClient.bytesWritten.connect(self.updateClientProgress)
        self.tcpClient.error.connect(self.displayError)

        mainLayout = QtGui.QVBoxLayout()
        mainLayout.addWidget(self.clientProgressBar)
        mainLayout.addWidget(self.clientStatusLabel)
        mainLayout.addWidget(self.serverProgressBar)
        mainLayout.addWidget(self.serverStatusLabel)
        mainLayout.addStretch(1)
        mainLayout.addSpacing(10)
        mainLayout.addWidget(buttonBox)
        self.setLayout(mainLayout)

        self.setWindowTitle("Loopback")

    def start(self):
        self.startButton.setEnabled(False)

        QtGui.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)

        self.bytesWritten = 0
        self.bytesReceived = 0

        while not self.tcpServer.isListening() and not self.tcpServer.listen():
            ret = QtGui.QMessageBox.critical(self, "Loopback",
                    "Unable to start the test: %s." % self.tcpServer.errorString(),
                    QtGui.QMessageBox.Retry | QtGui.QMessageBox.Cancel)
            if ret == QtGui.QMessageBox.Cancel:
                return

        self.serverStatusLabel.setText("Listening")
        self.clientStatusLabel.setText("Connecting")

        self.tcpClient.connectToHost(QtNetwork.QHostAddress(QtNetwork.QHostAddress.LocalHost), self.tcpServer.serverPort())

    def acceptConnection(self):
        self.tcpServerConnection = self.tcpServer.nextPendingConnection()
        self.tcpServerConnection.readyRead.connect(self.updateServerProgress)
        self.tcpServerConnection.error.connect(self.displayError)

        self.serverStatusLabel.setText("Accepted connection")
        self.tcpServer.close()

    def startTransfer(self):
        self.bytesToWrite = Dialog.TotalBytes - self.tcpClient.write(QtCore.QByteArray(Dialog.PayloadSize, '@'))
        self.clientStatusLabel.setText("Connected")

    def updateServerProgress(self):
        self.bytesReceived += self.tcpServerConnection.bytesAvailable()
        self.tcpServerConnection.readAll()

        self.serverProgressBar.setMaximum(Dialog.TotalBytes)
        self.serverProgressBar.setValue(self.bytesReceived)
        self.serverStatusLabel.setText("Received %dMB" % (self.bytesReceived / (1024 * 1024)))

        if self.bytesReceived == Dialog.TotalBytes:
            self.tcpServerConnection.close()
            self.startButton.setEnabled(True)
            QtGui.QApplication.restoreOverrideCursor()

    def updateClientProgress(self, numBytes):
        self.bytesWritten += numBytes
        if self.bytesToWrite > 0:
            self.bytesToWrite -= self.tcpClient.write(QtCore.QByteArray(
                                        min(self.bytesToWrite, Dialog.PayloadSize), '@'))

        self.clientProgressBar.setMaximum(Dialog.TotalBytes)
        self.clientProgressBar.setValue(self.bytesWritten)
        self.clientStatusLabel.setText("Sent %dMB" % (self.bytesWritten / (1024 * 1024)))

    def displayError(self, socketError):
        if socketError == QtNetwork.QTcpSocket.RemoteHostClosedError:
            return

        QtGui.QMessageBox.information(self, "Network error",
                "The following error occured: %s." % self.tcpClient.errorString())

        self.tcpClient.close()
        self.tcpServer.close()
        self.clientProgressBar.reset()
        self.serverProgressBar.reset()
        self.clientStatusLabel.setText("Client ready")
        self.serverStatusLabel.setText("Server ready")
        self.startButton.setEnabled(True)
        QtGui.QApplication.restoreOverrideCursor()


if __name__ == '__main__':

    import sys

    app = QtGui.QApplication(sys.argv)
    dialog = Dialog()
    dialog.show()
    sys.exit(dialog.exec_())