#!/usr/bin/env python


#############################################################################
##
## Copyright (C) 2010 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## 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.
##   * Redistributions in binary form must reproduce the above copyright
##     notice, this list of conditions and the following disclaimer in
##     the documentation and/or other materials provided with the
##     distribution.
##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
##     the names of its contributors may be used to endorse or promote
##     products derived from this software without specific prior written
##     permission.
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################


from PyQt4 import QtCore, QtGui, QtNetwork


class FortuneThread(QtCore.QThread):
    newFortune = QtCore.pyqtSignal(str)

    error = QtCore.pyqtSignal(int, str)

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

        self.quit = False
        self.hostName = ''
        self.cond = QtCore.QWaitCondition()
        self.mutex = QtCore.QMutex()
        self.port = 0

    def __del__(self):
        self.mutex.lock()
        self.quit = True
        self.cond.wakeOne()
        self.mutex.unlock()
        self.wait()

    def requestNewFortune(self, hostname, port):
        locker = QtCore.QMutexLocker(self.mutex)
        self.hostName = hostname
        self.port = port
        if not self.isRunning():
            self.start()
        else:
            self.cond.wakeOne()

    def run(self):
        self.mutex.lock()
        serverName = self.hostName
        serverPort = self.port
        self.mutex.unlock()

        while not self.quit:
            Timeout = 5 * 1000

            socket = QtNetwork.QTcpSocket()
            socket.connectToHost(serverName, serverPort)

            if not socket.waitForConnected(Timeout):
                self.error.emit(socket.error(), socket.errorString())
                return

            while socket.bytesAvailable() < 2:
                if not socket.waitForReadyRead(Timeout):
                    self.error.emit(socket.error(), socket.errorString())
                    return 

            instr = QtCore.QDataStream(socket)
            instr.setVersion(QtCore.QDataStream.Qt_4_0)
            blockSize = instr.readUInt16()

            while socket.bytesAvailable() < blockSize:
                if not socket.waitForReadyRead(Timeout):
                    self.error.emit(socket.error(), socket.errorString())
                    return

            self.mutex.lock()
            fortune = instr.readString()

            try:
                # Python v3.
                fortune = str(fortune, encoding='ascii')
            except TypeError:
                # Python v2.
                pass

            self.newFortune.emit(fortune)

            self.cond.wait(self.mutex)
            serverName = self.hostName
            serverPort = self.port
            self.mutex.unlock()


class BlockingClient(QtGui.QDialog):
    def __init__(self, parent=None):
        super(BlockingClient, self).__init__(parent)

        self.thread = FortuneThread()
        self.currentFortune = ''

        hostLabel = QtGui.QLabel("&Server name:")
        portLabel = QtGui.QLabel("S&erver port:")

        self.hostLineEdit = QtGui.QLineEdit('Localhost')
        self.portLineEdit = QtGui.QLineEdit()
        self.portLineEdit.setValidator(QtGui.QIntValidator(1, 65535, self))

        hostLabel.setBuddy(self.hostLineEdit)
        portLabel.setBuddy(self.portLineEdit)

        self.statusLabel = QtGui.QLabel("This example requires that you run "
                "the Fortune Server example as well.")

        self.getFortuneButton = QtGui.QPushButton("Get Fortune")
        self.getFortuneButton.setDefault(True)
        self.getFortuneButton.setEnabled(False)

        quitButton = QtGui.QPushButton("Quit")

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

        self.hostLineEdit.textChanged.connect(self.enableGetFortuneButton)
        self.portLineEdit.textChanged.connect(self.enableGetFortuneButton)
        self.getFortuneButton.clicked.connect(self.requestNewFortune)
        quitButton.clicked.connect(self.close)
        self.thread.newFortune.connect(self.showFortune)
        self.thread.error.connect(self.displayError)

        mainLayout = QtGui.QGridLayout()
        mainLayout.addWidget(hostLabel, 0, 0)
        mainLayout.addWidget(self.hostLineEdit, 0, 1)
        mainLayout.addWidget(portLabel, 1, 0)
        mainLayout.addWidget(self.portLineEdit, 1, 1)
        mainLayout.addWidget(self.statusLabel, 2, 0, 1, 2)
        mainLayout.addWidget(buttonBox, 3, 0, 1, 2)
        self.setLayout(mainLayout)

        self.setWindowTitle("Blocking Fortune Client")
        self.portLineEdit.setFocus()

    def requestNewFortune(self):
        self.getFortuneButton.setEnabled(False)
        self.thread.requestNewFortune(self.hostLineEdit.text(),
                int(self.portLineEdit.text()))

    def showFortune(self, nextFortune):
        if nextFortune == self.currentFortune:
            self.requestNewFortune()
            return

        self.currentFortune = nextFortune
        self.statusLabel.setText(self.currentFortune)
        self.getFortuneButton.setEnabled(True)

    def displayError(self, socketError, message):
        if socketError == QtNetwork.QAbstractSocket.HostNotFoundError:
            QtGui.QMessageBox.information(self, "Blocking Fortune Client",
                    "The host was not found. Please check the host and port "
                    "settings.")
        elif socketError == QtNetwork.QAbstractSocket.ConnectionRefusedError:
            QtGui.QMessageBox.information(self, "Blocking Fortune Client",
                    "The connection was refused by the peer. Make sure the "
                    "fortune server is running, and check that the host name "
                    "and port settings are correct.")
        else:
            QtGui.QMessageBox.information(self, "Blocking Fortune Client",
                    "The following error occurred: %s." % message)

        self.getFortuneButton.setEnabled(True)

    def enableGetFortuneButton(self):
        self.getFortuneButton.setEnabled(bool(self.hostLineEdit.text() and
                self.portLineEdit.text()))


if __name__ == '__main__':

    import sys

    app = QtGui.QApplication(sys.argv)
    client = BlockingClient()
    client.show()
    sys.exit(client.exec_())