acsm-calibre-plugin/calibre-plugin/config.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# pyright: reportUndefinedVariable=false

import os, base64, traceback

from lxml import etree

import time, datetime


from PyQt5.Qt import (Qt, QWidget, QHBoxLayout, QVBoxLayout, QLabel, QLineEdit,
                      QGroupBox, QPushButton, QListWidget, QListWidgetItem, QInputDialog, 
                      QLineEdit, QAbstractItemView, QIcon, QDialog, QDialogButtonBox, QUrl)

from PyQt5 import QtCore

from PyQt5 import Qt as QtGui
from zipfile import ZipFile

# calibre modules and constants.
from calibre.gui2 import (question_dialog, error_dialog, info_dialog, choose_save_file, choose_files)                     # type: ignore
# modules from this plugin's zipfile.
from calibre_plugins.deacsm.__init__ import PLUGIN_NAME, PLUGIN_VERSION      # type: ignore
import calibre_plugins.deacsm.prefs as prefs                                 # type: ignore
from calibre.utils.config import config_dir         # type: ignore
from calibre.constants import isosx, iswindows                 # type: ignore


class ConfigWidget(QWidget):
    def __init__(self, plugin_path):
        QWidget.__init__(self)

        self.plugin_path = plugin_path

        # get the prefs
        self.deacsmprefs = prefs.DeACSM_Prefs()

        # make a local copy
        self.tempdeacsmprefs = {}
        self.tempdeacsmprefs['path_to_account_data'] = self.deacsmprefs['path_to_account_data']

        self.tempdeacsmprefs['notify_fulfillment'] = self.deacsmprefs['notify_fulfillment']

        self.tempdeacsmprefs['list_of_rented_books'] = self.deacsmprefs['list_of_rented_books']


        # Start Qt Gui dialog layout
        layout = QVBoxLayout(self)
        self.setLayout(layout)


        ua_group_box = QGroupBox(_('Account information:'), self)
        layout.addWidget(ua_group_box)
        ua_group_box_layout = QVBoxLayout()
        ua_group_box.setLayout(ua_group_box_layout)

        info_string, activated, mail = self.get_account_info()

        self.lblAccInfo = QtGui.QLabel(self)
        self.lblAccInfo.setText(info_string)
        ua_group_box_layout.addWidget(self.lblAccInfo)

        if not activated: 
            self.button_link_account = QtGui.QPushButton(self)
            self.button_link_account.setText(_("Link to ADE account"))
            self.button_link_account.clicked.connect(self.link_account)
            ua_group_box_layout.addWidget(self.button_link_account)

            if isosx:
                self.button_import_MacADE = QtGui.QPushButton(self)
                self.button_import_MacADE.setText(_("Import activation from ADE (MacOS)"))
                self.button_import_MacADE.clicked.connect(self.import_activation_from_MAC)
                ua_group_box_layout.addWidget(self.button_import_MacADE)

            if iswindows:
                self.button_import_WinADE = QtGui.QPushButton(self)
                self.button_import_WinADE.setText(_("Import activation from ADE (Windows)"))
                self.button_import_WinADE.clicked.connect(self.import_activation_from_Win)
                ua_group_box_layout.addWidget(self.button_import_WinADE)

            self.button_import_activation = QtGui.QPushButton(self)
            self.button_import_activation.setText(_("Import existing activation backup (ZIP)"))
            self.button_import_activation.clicked.connect(self.import_activation_from_ZIP)
            ua_group_box_layout.addWidget(self.button_import_activation)

        else:
            self.button_switch_ade_version = QtGui.QPushButton(self)
            self.button_switch_ade_version.setText(_("Change ADE version"))
            self.button_switch_ade_version.clicked.connect(self.switch_ade_version)
            ua_group_box_layout.addWidget(self.button_switch_ade_version)


        self.button_export_key = QtGui.QPushButton(self)
        self.button_export_key.setText(_("Export account encryption key"))
        self.button_export_key.clicked.connect(self.export_key)
        self.button_export_key.setEnabled(activated)
        ua_group_box_layout.addWidget(self.button_export_key)

        self.button_export_activation = QtGui.QPushButton(self)
        self.button_export_activation.setText(_("Export account activation data"))
        self.button_export_activation.clicked.connect(self.export_activation)
        self.button_export_activation.setEnabled(activated)
        ua_group_box_layout.addWidget(self.button_export_activation)

        self.button_rented_books = QtGui.QPushButton(self)
        self.button_rented_books.setText(_("Show loaned books"))
        self.button_rented_books.clicked.connect(self.show_rented_books)
        self.button_rented_books.setEnabled(activated)
        ua_group_box_layout.addWidget(self.button_rented_books)

        if (len(self.deacsmprefs["list_of_rented_books"]) == 0):
            self.button_rented_books.setEnabled(False)


        self.chkNotifyFulfillment = QtGui.QCheckBox("Notify ACS server after successful fulfillment")
        self.chkNotifyFulfillment.setToolTip("Default: True\n\nIf this is enabled, the ACS server will receive a notification once the ACSM has successfully been converted. \nThis is not strictly necessary, but it is what ADE does, so it's probably safer to just do it as well.\nAlso, it is required to be able to return loaned books.")
        self.chkNotifyFulfillment.setChecked(self.tempdeacsmprefs["notify_fulfillment"])
        layout.addWidget(self.chkNotifyFulfillment)


        try: 
            from calibre_plugins.deacsm.libadobe import createDeviceKeyFile, update_account_path, are_ade_version_lists_valid
            from calibre_plugins.deacsm.libadobeAccount import createDeviceFile, createUser, signIn, activateDevice
        except: 
            try: 
                from libadobe import createDeviceKeyFile, update_account_path, are_ade_version_lists_valid
                from libadobeAccount import createDeviceFile, createUser, signIn, activateDevice
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()


        update_account_path(self.deacsmprefs["path_to_account_data"])
        self.resize(self.sizeHint())

        if not are_ade_version_lists_valid():
            # Internal error, this should never happen
            if not activated:
                self.button_link_account.setEnabled(False)
                self.button_import_activation.setEnabled(False)
                if isosx:
                    self.button_import_MacADE.setEnabled(activated)
                if iswindows:
                    self.button_import_WinADE.setEnabled(activated)
            else:
                self.button_switch_ade_version.setEnabled(False)
            self.button_export_key.setEnabled(False)
            self.button_export_activation.setEnabled(False)
            self.button_rented_books.setEnabled(False)
            self.chkNotifyFulfillment.setEnabled(False)

            error_dialog(None, "Internal error", "Version list mismatch. Please open a bug report.", show=True, show_copy_button=False)

        

    def get_account_info(self): 

        try: 
            from calibre_plugins.deacsm.libadobe import VAR_VER_SUPP_CONFIG_NAMES, VAR_VER_HOBBES_VERSIONS
        except: 
            try: 
                from libadobe import VAR_VER_SUPP_CONFIG_NAMES, VAR_VER_HOBBES_VERSIONS
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()

        activation_xml_path = os.path.join(self.deacsmprefs["path_to_account_data"], "activation.xml")
        device_xml_path = os.path.join(self.deacsmprefs["path_to_account_data"], "device.xml")

        container = None
        try: 
            container = etree.parse(activation_xml_path)
            containerdev = etree.parse(device_xml_path)
        except (FileNotFoundError, OSError) as e:
            return "Not authorized for any ADE ID", False, None

        try: 
            adeptNS = lambda tag: '{%s}%s' % ('http://ns.adobe.com/adept', tag)        
            devicenameXML = containerdev.find(adeptNS("deviceName"))
            ade_device_name = devicenameXML.text
            
            anon = False
            try: 
                usernameXML = container.find(adeptNS("credentials")).find(adeptNS("username"))
                ade_type = usernameXML.get('method', "unknown")
                ade_mail = usernameXML.text
            except: 
                anon = True
            

            # Determine the ADE version we're emulating:
            ver = containerdev.findall("./%s" % (adeptNS("version")))
            ADE_version = None

            for f in ver:
                if f.get("name") == "hobbes":
                    hobbes_version = f.get("value")
            
            if hobbes_version is not None:
                try: 
                    v_idx = VAR_VER_HOBBES_VERSIONS.index(hobbes_version)
                    ADE_version = VAR_VER_SUPP_CONFIG_NAMES[v_idx] + " (" + hobbes_version + ")"

                except:
                    # Version not present, probably the "old" 10.0.4 entry. 
                    # As 10.X is in the 3.0 range, assume we're on ADE 3.0
                    ADE_version = "ADE 3.0.1 (" + hobbes_version + ")"
          

            if container.find(adeptNS("activationToken")) == None:
                return "ADE authorization seems to be corrupted (activationToken missing)", False, None

            if container.find(adeptNS("credentials")).find(adeptNS("pkcs12")) == None:
                return "ADE authorization seems to be corrupted (pkcs12 missing)", False, None

            if not anon: 
                return "Authorized with ADE ID ("+ade_type+") " + ade_mail + "\non device " + ade_device_name + ", emulating " + ADE_version + ".", True, ade_mail
            else: 
                return "Authorized with an anonymous ADE ID\non device " + ade_device_name + ", emulating " + ADE_version + ".", True, None
        except: 
            traceback.print_exc()
            return "ADE authorization seems to be corrupted", False, None


    def export_activation(self):

        try: 
            from calibre_plugins.deacsm.libadobe import update_account_path
            from calibre_plugins.deacsm.libadobeAccount import getAccountUUID
        except: 
            try: 
                from libadobe import update_account_path
                from libadobeAccount import getAccountUUID
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()


        update_account_path(self.deacsmprefs["path_to_account_data"])

        account_uuid = None
        export_filename = "adobe_account_backup.zip"
        try: 
            account_uuid = getAccountUUID()
            export_filename = "adobe_account_backup_uuid_" + account_uuid + ".zip"
        except:
            pass

        filters = [("ZIP", ["zip"])]
        filename = choose_save_file(self, "Export ADE activation files", _("Export ADE activation files"), 
                filters, all_files=False, initial_filename=export_filename)

        if (filename is None):
            return

        print("{0} v{1}: Exporting activation data to {2}".format(PLUGIN_NAME, PLUGIN_VERSION, filename))

        try: 
            with ZipFile(filename, 'w') as zipfile:
                zipfile.write(os.path.join(self.deacsmprefs["path_to_account_data"], "device.xml"), "device.xml")
                zipfile.write(os.path.join(self.deacsmprefs["path_to_account_data"], "activation.xml"), "activation.xml")
                zipfile.write(os.path.join(self.deacsmprefs["path_to_account_data"], "devicesalt"), "devicesalt")
        except: 
            return error_dialog(None, "Export failed", "Export failed.", show=True, show_copy_button=False)

    def import_activation_from_Win(self):
        # This will try to import the activation from Adobe Digital Editions on Windows ...

        from calibre_plugins.deacsm.libadobeImportAccount import importADEactivationWindows

        ret, msg = importADEactivationWindows()

        if (ret):
            # update display
            info_string, activated, ade_mail = self.get_account_info()
            self.lblAccInfo.setText(info_string)

            self.button_link_account.setEnabled(not activated)
            self.button_import_activation.setEnabled(not activated)
            self.button_export_key.setEnabled(activated)
            self.button_export_activation.setEnabled(activated)
            self.button_import_WinADE.setEnabled(activated)

            self.resize(self.sizeHint())

            if (activated):
                if ade_mail is None: 
                    info_dialog(None, "Done", "Successfully imported an anonymous authorization", show=True, show_copy_button=False)
                else: 
                    info_dialog(None, "Done", "Successfully imported authorization for " + ade_mail, show=True, show_copy_button=False)
            else: 
                error_dialog(None, "Import failed", "Import looks like it worked, but the resulting files seem to be corrupted ...", show=True, show_copy_button=False)
        else: 
            error_dialog(None, "Import failed", "That didn't work:\n" + msg, show=True, show_copy_button=False)

    def import_activation_from_MAC(self):
        # This will try to import the activation from Adobe Digital Editions on MacOS ...

        msg = "Trying to import existing activation from Adobe Digital Editions ...\n"
        msg += "You might get a prompt asking you to unlock your keychain / enter your keychain password.\n"
        msg += "This is necessary to extract the ADE encryption keys. "

        info_dialog(None, "Importing from ADE", msg, show=True, show_copy_button=False)

        from calibre_plugins.deacsm.libadobeImportAccount import importADEactivationMac

        ret, msg = importADEactivationMac()

        if (ret):
            # update display
            info_string, activated, ade_mail = self.get_account_info()
            self.lblAccInfo.setText(info_string)

            self.button_link_account.setEnabled(not activated)
            self.button_import_activation.setEnabled(not activated)
            self.button_export_key.setEnabled(activated)
            self.button_export_activation.setEnabled(activated)
            self.button_import_MacADE.setEnabled(activated)

            self.resize(self.sizeHint())

            if (activated):
                if ade_mail is None: 
                    info_dialog(None, "Done", "Successfully imported an anonymous authorization", show=True, show_copy_button=False)
                else: 
                    info_dialog(None, "Done", "Successfully imported authorization for " + ade_mail, show=True, show_copy_button=False)
            else: 
                error_dialog(None, "Import failed", "Import looks like it worked, but the resulting files seem to be corrupted ...", show=True, show_copy_button=False)
        else: 
            error_dialog(None, "Import failed", "That didn't work:\n" + msg, show=True, show_copy_button=False)



    def import_activation_from_ZIP(self):

        filters = [("ZIP", ["zip"])]
        filenames = choose_files(self, "Import ADE activation file (ZIP)", _("Import ADE activation file (ZIP)"), 
                filters, all_files=False, select_only_single_file=True)
        
        try: 
            filename = filenames[0]
            if (filename is None):
                return
        except: 
            return

        print("{0} v{1}: Importing activation data from {2}".format(PLUGIN_NAME, PLUGIN_VERSION, filename))

        with ZipFile(filename, 'r') as zipfile:
            try: 
                device = zipfile.read("device.xml")
                activation = zipfile.read("activation.xml")
                salt = zipfile.read("devicesalt")
            except: 
                return error_dialog(None, "Import failed", "Can't find required files in this ZIP")

            try: 
                output_device = open(os.path.join(self.deacsmprefs["path_to_account_data"], "device.xml"), "w")
                output_device.write(device.decode("utf-8"))
                output_device.close()

                output_activation = open(os.path.join(self.deacsmprefs["path_to_account_data"], "activation.xml"), "w")
                output_activation.write(activation.decode("utf-8"))
                output_activation.close()

                output_salt = open(os.path.join(self.deacsmprefs["path_to_account_data"], "devicesalt"), "wb")
                output_salt.write(salt)
                output_salt.close()

            except: 
                err = traceback.format_exc()
                return error_dialog(None, "Import failed", "Can't write file", show=True, det_msg=err, show_copy_button=False)

        # update display
        info_string, activated, ade_mail = self.get_account_info()
        self.lblAccInfo.setText(info_string)

        self.button_link_account.setEnabled(not activated)
        self.button_import_activation.setEnabled(not activated)
        self.button_export_key.setEnabled(activated)
        self.button_export_activation.setEnabled(activated)
        try: 
            self.button_import_MacADE.setEnabled(activated)
        except:
            pass
        
        try: 
            self.button_import_WinADE.setEnabled(activated)
        except:
            pass

        self.resize(self.sizeHint())

        if ade_mail is None: 
            info_dialog(None, "Done", "Successfully imported an anonymous authorization.", show=True, show_copy_button=False)
        else: 
            info_dialog(None, "Done", "Successfully imported authorization for " + ade_mail, show=True, show_copy_button=False)


    def switch_ade_version(self): 
        try: 
            from calibre_plugins.deacsm.libadobe import VAR_VER_HOBBES_VERSIONS, VAR_VER_SUPP_CONFIG_NAMES
            from calibre_plugins.deacsm.libadobe import VAR_VER_BUILD_IDS, VAR_VER_ALLOWED_BUILD_IDS_SWITCH_TO
            from calibre_plugins.deacsm.libadobeAccount import changeDeviceVersion
        except: 
            try: 
                from libadobe import VAR_VER_HOBBES_VERSIONS, VAR_VER_SUPP_CONFIG_NAMES
                from libadobe import VAR_VER_BUILD_IDS, VAR_VER_ALLOWED_BUILD_IDS_SWITCH_TO
                from libadobeAccount import changeDeviceVersion
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()


        device_xml_path = os.path.join(self.deacsmprefs["path_to_account_data"], "device.xml")

        try: 
            containerdev = etree.parse(device_xml_path)
        except (FileNotFoundError, OSError) as e:
            return error_dialog(None, "Failed", "Error while reading file", show=True, show_copy_button=False)

        try: 
            adeptNS = lambda tag: '{%s}%s' % ('http://ns.adobe.com/adept', tag)        

            # Determine the ADE version we're emulating:
            ver = containerdev.findall("./%s" % (adeptNS("version")))

            # "Default" entry would be for the old 10.0.4 entry. 
            # As 10.X is in the 3.0 range, assume we're on ADE 3.0.1 with hobbes version 10.0.85385
            v_idx = VAR_VER_HOBBES_VERSIONS.index("10.0.85385")

            for f in ver:
                if f.get("name") == "hobbes":
                    hobbes_version = f.get("value")

            
            if hobbes_version is not None:
                ADE_version = "ADE 3.0.X (RMSDK " + hobbes_version + ")"
                try: 
                    v_idx = VAR_VER_HOBBES_VERSIONS.index(hobbes_version)
                    ADE_version = VAR_VER_SUPP_CONFIG_NAMES[v_idx] + " (RMSDK " + hobbes_version + ")"
                except:
                    pass
            else: 
                ADE_version = "ADE 3.0.X"


        except: 
            err = traceback.format_exc()
            return error_dialog(None, "Failed", "Error while determining current ADE version.", show=True, det_msg=err, show_copy_button=False)


        # Build a list of allowed strings:
        allowed_strings = []
        for allowed_id in VAR_VER_ALLOWED_BUILD_IDS_SWITCH_TO:
            try: 
                idx = VAR_VER_BUILD_IDS.index(allowed_id)
            except:
                pass
        
            try: 
                allowed_strings.append(VAR_VER_SUPP_CONFIG_NAMES[idx])
            except:
                pass
        
        if len(allowed_strings) == 0:
            return error_dialog(None, "Failed", "Error determining available versions", show=True, show_copy_button=True)


        msg = "You are currently using " + ADE_version + "\n"
        msg += "You can switch to a different ADE version by using the selection box below.\n"
        msg += "- ADE 1.7.2 is for debugging only. Do not use this setting, it might get your account banned\n"
        msg += "- ADE 2.0.1 works with most books, and will always get you the old, removable DRM. Select this if you're unsure\n"
        msg += "- ADE 3.0.1 works with all books, but may give you unremovable DRM for some retailers\n"
        msg += "- ADE 4.0.3 and ADE 4.5.11 are available, but aren't really needed for anything\n"
        msg += "Select ADE 2.0.1 if you are unsure\n\n"
        msg += "Which ADE version do you want to emulate?"

        item, ok = QInputDialog.getItem(self, "Change ADE version", msg, VAR_VER_SUPP_CONFIG_NAMES, 1, False)

        if (not ok):
            return

        idx = -1
        try: 
            idx = VAR_VER_SUPP_CONFIG_NAMES.index(item)
            ret, msg = changeDeviceVersion(idx)
            if (ret):
                # Update info display:
                info_string, activated, mail = self.get_account_info()
                self.lblAccInfo.setText(info_string)
                return info_dialog(None, "Done", "Successfully switched to " + item, show=True, show_copy_button=False)
            else: 
                return error_dialog(None, "Failed", "Error while changing ADE version: " + msg, show=True, show_copy_button=False)    

        except: 
            return error_dialog(None, "Failed", "Error while changing ADE version.", show=True, det_msg=err, show_copy_button=False)
            

    def link_account(self):

        try: 
            from calibre_plugins.deacsm.libadobe import createDeviceKeyFile, update_account_path, VAR_VER_SUPP_CONFIG_NAMES
            from calibre_plugins.deacsm.libadobe import VAR_VER_ALLOWED_BUILD_IDS_AUTHORIZE, VAR_VER_BUILD_IDS, VAR_VER_DEFAULT_BUILD_ID
            from calibre_plugins.deacsm.libadobeAccount import createDeviceFile, createUser, signIn, activateDevice
        except: 
            try: 
                from libadobe import createDeviceKeyFile, update_account_path, VAR_VER_SUPP_CONFIG_NAMES
                from libadobe import VAR_VER_ALLOWED_BUILD_IDS_AUTHORIZE, VAR_VER_BUILD_IDS, VAR_VER_DEFAULT_BUILD_ID
                from libadobeAccount import createDeviceFile, createUser, signIn, activateDevice
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()

        update_account_path(self.deacsmprefs["path_to_account_data"])
        
        mail, ok = QInputDialog.getText(self, "Authorizing ADE account", "Please enter mail address")

        if (not ok or mail is None or len(mail) == 0):
            return

        passwd, ok = QInputDialog.getText(self, "Authorizing ADE account", "Please enter password", QLineEdit.Password)

        if (not ok or passwd is None or len(passwd) == 0):
            return

        # Build a list of allowed strings:
        allowed_strings = []

        for allowed_id in VAR_VER_ALLOWED_BUILD_IDS_AUTHORIZE:
            idx = VAR_VER_BUILD_IDS.index(allowed_id)
            allowed_strings.append(VAR_VER_SUPP_CONFIG_NAMES[idx])

        
        if len(allowed_strings) == 0:
            return error_dialog(None, "ADE activation failed", "Error determining available versions", show=True, show_copy_button=True)


        msg = "Which ADE version do you want to emulate?\n"
        msg += "- ADE 2.0.1 works with most but not all books, but will always give you the old, removable DRM.\n"
        msg += "- ADE 3.0.1 works with all books, but may give you unremovable DRM for some retailers.\n"
        msg += "- ADE 4.0.3 and 4.5.11 are only provided for completeness sake, but aren't usually needed.\n"
        msg += "Select ADE 2.0 if you are unsure."
        item, ok = QInputDialog.getItem(self, "Authorizing ADE account", msg, allowed_strings, 
            VAR_VER_ALLOWED_BUILD_IDS_AUTHORIZE.index(VAR_VER_DEFAULT_BUILD_ID), False)

        if (not ok):
            return

        idx = 0
        try: 
            idx = VAR_VER_SUPP_CONFIG_NAMES.index(item)
            print("User selected ({0}) -> {1}".format(idx, VAR_VER_SUPP_CONFIG_NAMES[idx]))
        except: 
            resp = traceback.format_exc()
            return error_dialog(None, "ADE activation failed", "Error determining version", det_msg=str(resp), show=True, show_copy_button=True)
                
        createDeviceKeyFile()
        createDeviceFile(False, idx)
        success, resp = createUser(idx)
        if (success is False):
            return error_dialog(None, "ADE activation failed", "Couldn't create user", det_msg=str(resp), show=True, show_copy_button=True)

        success, resp = signIn(mail, passwd)
        if (success is False):
            return error_dialog(None, "ADE activation failed", "Login unsuccessful", det_msg=str(resp), show=True, show_copy_button=True)

        success, resp = activateDevice(idx)
        if (success is False):
            return error_dialog(None, "ADE activation failed", "Couldn't activate device", det_msg=str(resp), show=True, show_copy_button=True)

        print("Authorized to account " + mail)


        # update display
        info_string, activated, mail = self.get_account_info()
        self.lblAccInfo.setText(info_string)

        self.button_link_account.setEnabled(False)
        self.button_import_activation.setEnabled(False)
        self.button_export_key.setEnabled(True)
        self.button_export_activation.setEnabled(True)
        try: 
            self.button_import_MacADE.setEnabled(False)
        except:
            pass
        try: 
            self.button_import_WinADE.setEnabled(False)
        except:
            pass

        self.resize(self.sizeHint())

        info_dialog(None, "Done", "Authorized to account " + mail, show=True, show_copy_button=False)




    def export_key(self):

        try: 
            from calibre_plugins.deacsm.libadobe import update_account_path
            from calibre_plugins.deacsm.libadobeAccount import exportAccountEncryptionKeyDER, getAccountUUID
        except: 
            try: 
                from libadobe import update_account_path
                from libadobeAccount import exportAccountEncryptionKeyDER, getAccountUUID
            except: 
                print("{0} v{1}: Error while importing Account stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()


        update_account_path(self.deacsmprefs["path_to_account_data"])

        filters = [("DER Files", ["der"])]

        account_uuid = None
        export_filename = "adobe_encryption_key.der"
        try: 
            account_uuid = getAccountUUID()
            export_filename = "adobe_uuid_" + account_uuid + ".der"
        except:
            pass

        filename = choose_save_file(self, "Export ADE keys", _("Export ADE keys"), filters, 
                    all_files=False, initial_filename=export_filename)

        if (filename is None):
            return

        print("{0} v{1}: Exporting encryption key to {2}".format(PLUGIN_NAME, PLUGIN_VERSION, filename))

        ret = exportAccountEncryptionKeyDER(filename)

        if ret:
            return info_dialog(None, "Done", "Key successfully exported", show=True, show_copy_button=False)
        else: 
            return error_dialog(None, "Export failed", "Export failed", show=True, show_copy_button=False)



    def save_settings(self):
        self.deacsmprefs.set('notify_fulfillment', self.chkNotifyFulfillment.isChecked())
        self.deacsmprefs.writeprefs()

    def load_resource(self, name):
        with ZipFile(self.plugin_path, 'r') as zf:
            if name in zf.namelist():
                return zf.read(name).decode('utf-8')
        return ""



    def show_rented_books(self):
        d = RentedBooksDialog(self, self.deacsmprefs["list_of_rented_books"])
        d.exec_()


class RentedBooksDialog(QDialog):
    def __init__(self, parent, booklist):
        QDialog.__init__(self,parent)
        self.parent = parent

        self.setWindowTitle("DeACSM: Manage loaned Books")

        # Start Qt Gui dialog layout
        layout = QVBoxLayout(self)
        self.setLayout(layout)

        keys_group_box = QGroupBox("List of loaned books", self)
        layout.addWidget(keys_group_box)
        keys_group_box_layout = QHBoxLayout()
        keys_group_box.setLayout(keys_group_box_layout)

        self.listy = QListWidget(self)
        self.listy.setToolTip("List of loaned books")
        self.listy.setSelectionMode(QAbstractItemView.SingleSelection)
        self.populate_list()
        keys_group_box_layout.addWidget(self.listy)


        button_layout = QVBoxLayout()
        keys_group_box_layout.addLayout(button_layout)
        self._add_key_button = QtGui.QToolButton(self)
        self._add_key_button.setIcon(QIcon(I('view-refresh.png')))
        self._add_key_button.setToolTip("Return book to library")
        self._add_key_button.clicked.connect(self.return_book)
        button_layout.addWidget(self._add_key_button)

        self._delete_key_button = QtGui.QToolButton(self)
        self._delete_key_button.setToolTip(_("Delete book entry from list"))
        self._delete_key_button.setIcon(QIcon(I('list_remove.png')))
        self._delete_key_button.clicked.connect(self.delete_book_entry)
        button_layout.addWidget(self._delete_key_button)

        self.lblAccInfo = QtGui.QLabel(self)
        self.lblAccInfo.setText("Click the arrow button to return a loaned book to the library.\nClick the red X to delete the loan record without returning the book.")
        layout.addWidget(self.lblAccInfo)

        self.button_box = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
        self.button_box.accepted.connect(self.accept)
        self.button_box.rejected.connect(self.reject)
        layout.addWidget(self.button_box)

        self.resize(self.sizeHint())

    def td_format(self, td_object):
        seconds = int(td_object.total_seconds())
        periods = [
            ('y',        60*60*24*365),
            ('M',        60*60*24*30),
            ('d',        60*60*24),
            ('h',        60*60),
            ('m',        60),
            ('s',        1)
        ]

        strings=[]
        tick = 0
        for period_name, period_seconds in periods:
            if seconds > period_seconds:
                period_value , seconds = divmod(seconds, period_seconds)
                strings.append("%s%s" % (period_value, period_name))
                tick += 1
            if tick >= 2:
                break

        return " ".join(strings)

    def populate_list(self):
        self.listy.clear()

        overdue_books = []

        for book in self.parent.deacsmprefs["list_of_rented_books"]:

            try: 
                book_time_stamp = book["validUntil"]
                timestamp = datetime.datetime.strptime(book_time_stamp, "%Y-%m-%dT%H:%M:%SZ")
                currenttime = datetime.datetime.utcnow()
            except: 
                print("Invalid book timestamp")
                continue


            if (timestamp <= currenttime):
                # Book is overdue, no need to return. Delete from list.
                overdue_books.append(book)
                continue
            else: 
                info = "(" + self.td_format(timestamp - currenttime)
                info += " remaining)"


            item = QListWidgetItem(book["book_name"] + " " + info)
            item.setData(QtCore.Qt.UserRole, book["loanID"])
            self.listy.addItem(item)

        for book in overdue_books:
            self.parent.deacsmprefs["list_of_rented_books"].remove(book)

        self.parent.deacsmprefs.writeprefs()


    def return_book(self): 
        if not self.listy.currentItem(): 
            return

        userdata = str(self.listy.currentItem().data(QtCore.Qt.UserRole))
        print("Returning book %s (ID %s)" % (self.listy.currentItem().text(), userdata))


        try: 
            from calibre_plugins.deacsm.libadobeFulfill import tryReturnBook
        except: 
            try: 
                from libadobeFulfill import tryReturnBook
            except: 
                print("{0} v{1}: Error while importing book return stuff".format(PLUGIN_NAME, PLUGIN_VERSION))
                traceback.print_exc()

        Ret_book = None
        for book in self.parent.deacsmprefs["list_of_rented_books"]:
            if book["loanID"] == userdata:
                Ret_book = book
                break

        if Ret_book is None: 
            return

        ret, msg = tryReturnBook(Ret_book)

        if (ret):
            print("Book successfully returned:")
            print(msg)
            self.delete_book_entry(nomsg=True)
            self.populate_list()
            return info_dialog(None, "Done", "Book successfully returned", show=True, show_copy_button=False)
        else: 
            print("Book return failed:")
            print(msg)
            return error_dialog(None, "Error", "Book return failed", det_msg=msg, show=True, show_copy_button=False)


    def delete_book_entry(self, nomsg = False): 
        if not self.listy.currentItem(): 
            return

        userdata = str(self.listy.currentItem().data(QtCore.Qt.UserRole))
        print("Deleting book entry %s (ID %s)" % (self.listy.currentItem().text(), userdata))

        success = False
        for book in self.parent.deacsmprefs["list_of_rented_books"]:
            if book["loanID"] == userdata:
                self.parent.deacsmprefs["list_of_rented_books"].remove(book)
                success = True
                break

        self.populate_list()

        if success and not nomsg:
            return info_dialog(None, "Done", "Book entry deleted without returning.", show=True, show_copy_button=False)
        if not nomsg: 
            return error_dialog(None, "Error", "Error while deleting book entry", show=True, show_copy_button=False)