#!/bin/env python

# -*- coding: utf-8 -*-

# ------------------------------------------------------------

# download-osec-vm-image 

# 

# download the initial OsecVM.ova image

#

# Copyright 2013-2014 X-Net and AIT Austrian Institute of Technology

# 

# 

#     X-Net Services GmbH

#     Elisabethstrasse 1

#     4020 Linz

#     AUSTRIA

#     https://www.x-net.at

# 

#     AIT Austrian Institute of Technology

#     Donau City Strasse 1

#     1220 Wien

#     AUSTRIA

#     http://www.ait.ac.at

# 

# 

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

# 

#    http://www.apache.org/licenses/LICENSE-2.0

# 

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# ------------------------------------------------------------

# ------------------------------------------------------------

# imports

import errno

import os

import sys

import urllib2

from PyQt4 import QtCore

from PyQt4 import QtGui

# local

from environment import Environment

# ------------------------------------------------------------

# global vars

vm_path = os.path.normpath(os.path.join(sys.path[0], '..', 'vm'))

# ------------------------------------------------------------

# code

class DownloadDialog(QtGui.QDialog):

    """Download the initial OsecVM image dialog."""

    def __init__(self, parent = None, flags = QtCore.Qt.WindowFlags(0)):

        # super call and widget init

        super(DownloadDialog, self).__init__(parent, flags)

        self.setWindowTitle('Download initial OpenSecurity VM image')

        self.setup_ui()

        # setup download thread

        self._downloader = Downloader()

        self._downloader.downloaded.connect(self.downloader_update)

        self._thread = QtCore.QThread()

        self._downloader.moveToThread(self._thread)

        self._downloader.finished.connect(self._thread.quit)

        self._thread.started.connect(self._downloader.work)

        self._thread.finished.connect(self.finished_downloader)

        self._thread.start() 

    def clicked_cancel(self):

        """button cancel clicked"""

        # tell download thread to stop

        self._downloader.stop = True

    def downloader_update(self, current, total):

        """New download values present"""

        if self.pbDownload.minimum() != 0:

            self.pbDownload.setMinimum(0)

        if self.pbDownload.maximum() != total:

            self.pbDownload.setMaximum(total)

        self.pbDownload.setValue(current)

    def finished_downloader(self):

        """Download thread has finished (either success or abort)"""

        if not self._downloader.error is None:

            QtGui.QMessageBox.critical(None, 'OpenSecurity Download VM image error', self._downloader.error)

        self.accept();

    def setup_ui(self):

        """Create the widgets."""

        lyMain = QtGui.QVBoxLayout(self)

        lyMain.setContentsMargins(8, 8, 8, 8)

        lbTitle = QtGui.QLabel('Downloading OpenSecurity VM image')

        lyMain.addWidget(lbTitle)

        self.pbDownload = QtGui.QProgressBar()

        self.pbDownload.setTextVisible(True)

        lyMain.addWidget(self.pbDownload)

        # buttons

        lyButton = QtGui.QHBoxLayout()

        lyMain.addLayout(lyButton)

        lyButton.addStretch(1)

        btnCancel = QtGui.QPushButton('&Cancel', self)

        btnCancel.setMinimumWidth(100)

        lyButton.addWidget(btnCancel)

        # connectors

        btnCancel.clicked.connect(self.clicked_cancel)

        # reduce to the max

        self.setMinimumWidth(400)

        self.resize(lyMain.minimumSize())

class Downloader(QtCore.QObject):

    """This is the worker thread when downloading"""

    downloaded = QtCore.pyqtSignal(int, int)

    finished = QtCore.pyqtSignal()

    def __init__(self):

        # super call 

        super(Downloader, self).__init__()

        self.error = None

        self.stop = False

        # place to store the OsecVM image

        if not os.path.exists(vm_path):

            os.mkdir(vm_path)

    def work(self):

        """Thread method: download until finished or stopped"""

        url = "http://service.x-net.at/opensecurity/OsecVM_latest.ova"

        filename_download = os.path.join(vm_path, 'OsecVM_latest.ova')

        filename_target = os.path.join(vm_path, 'OsecVM.ova')

        # open URL

        try: 

            resp = urllib2.urlopen(url)

        except urllib2.URLError as e:

            self.error = 'URLError: ' + str(e.reason)

            self.finished.emit()

            return

        except urllib2.HTTPError as e:

            self.error = 'HTTPError: ' + str(e.reason)

            self.finished.emit()

            return

        # download a CHUNK of data and then update the GUI

        totalSize = int(resp.info().getheader('Content-Length').strip())

        currentSize = 0

        CHUNK_SIZE = 32768

        self.downloaded.emit(currentSize, totalSize)

        f = open(filename_download, 'w')

        while (not self.stop) and (currentSize < totalSize):

            data = resp.read(CHUNK_SIZE)

            currentSize += len(data)

            f.write(data)

            self.downloaded.emit(currentSize, totalSize)

        f.flush()

        f.close()

        # rename the download to OsecVM.ova

        if os.path.exists(filename_target):

            os.remove(filename_target)

        os.rename(filename_download, filename_target)

        self.finished.emit()

def main():

    """entry point"""

    # launch Qt

    global app

    app = QtGui.QApplication(sys.argv)

    # prebuild the pixmap cache: fetch all jpg, png and jpeg images and load them

    image_path = os.path.join(sys.path[0], '..', 'gfx')

    for file in os.listdir(image_path):

        if file.lower().rpartition('.')[2] in ('jpg', 'png', 'jpeg'):

            QtGui.QPixmapCache.insert(file.lower().rpartition('.')[0], QtGui.QPixmap(os.path.join(image_path, file)))

    # we should have now our application icon

    app.setWindowIcon(QtGui.QIcon(QtGui.QPixmapCache.find('opensecurity_icon_64')))

    # check essential permissions

    try:

        f = open(os.path.join(vm_path, '.x'), 'w')

        f.write('test')

        f.flush()

        f.close()

        os.remove(os.path.join(vm_path, '.x'))

    except IOError as e:

        if e.errno == errno.EACCES:

            QtGui.QMessageBox.critical(None, 'OpenSecurity Download VM image error', 'No write access to "' + str(vm_path) + '"\nIs this run as Administrator?')

            sys.exit(1)

        else:

            QtGui.QMessageBox.critical(None, 'OpenSecurity Download VM image error', 'Error occured.\nErrno: ' + str(e.errno))

            sys.exit(1)

    # open download dialog

    w = DownloadDialog()

    w.show()

    # on with the show

    sys.exit(app.exec_())

# start

if __name__ == "__main__":

    main()