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

# Copyright (c) 2016 - 2018 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to edit the SSL error exceptions.
"""

from __future__ import unicode_literals

from PyQt5.QtCore import pyqtSlot, Qt, QPoint
from PyQt5.QtWidgets import QDialog, QTreeWidgetItem, QMenu
from PyQt5.QtWebEngineWidgets import QWebEngineCertificateError

from .Ui_SslErrorExceptionsDialog import Ui_SslErrorExceptionsDialog


class SslErrorExceptionsDialog(QDialog, Ui_SslErrorExceptionsDialog):
    """
    Class implementing a dialog to edit the SSL error exceptions.
    """
    def __init__(self, errorsDict, parent=None):
        """
        Constructor
        
        @param errorsDict error exceptions
        @type dict of list of int
        @param parent reference to the parent widget
        @type QWidget
        """
        super(SslErrorExceptionsDialog, self).__init__(parent)
        self.setupUi(self)
        
        self.__errorDescriptions = {
            QWebEngineCertificateError.SslPinnedKeyNotInCertificateChain:
                self.tr("The certificate did not match the built-in public"
                        " keys pinned for the host name."),
            QWebEngineCertificateError.CertificateCommonNameInvalid:
                self.tr("The certificate's common name did not match the"
                        " host name."),
            QWebEngineCertificateError.CertificateDateInvalid:
                self.tr("The certificate is not valid at the current date"
                        " and time."),
            QWebEngineCertificateError.CertificateAuthorityInvalid:
                self.tr("The certificate is not signed by a trusted"
                        " authority."),
            QWebEngineCertificateError.CertificateContainsErrors:
                self.tr("The certificate contains errors."),
            QWebEngineCertificateError.CertificateNoRevocationMechanism:
                self.tr("The certificate has no mechanism for determining if"
                        " it has been revoked."),
            QWebEngineCertificateError.CertificateUnableToCheckRevocation:
                self.tr("Revocation information for the certificate is"
                        " not available."),
            QWebEngineCertificateError.CertificateRevoked:
                self.tr("The certificate has been revoked."),
            QWebEngineCertificateError.CertificateInvalid:
                self.tr("The certificate is invalid."),
            QWebEngineCertificateError.CertificateWeakSignatureAlgorithm:
                self.tr("The certificate is signed using a weak signature"
                        " algorithm."),
            QWebEngineCertificateError.CertificateNonUniqueName:
                self.tr("The host name specified in the certificate is"
                        " not unique."),
            QWebEngineCertificateError.CertificateWeakKey:
                self.tr("The certificate contains a weak key."),
            QWebEngineCertificateError.CertificateNameConstraintViolation:
                self.tr("The certificate claimed DNS names that are in"
                        " violation of name constraints."),
        }
        try:
            self.__errorDescriptions[
                QWebEngineCertificateError.CertificateValidityTooLong] = \
                self.tr("The certificate has a validity period that is"
                        " too long.")
        except AttributeError:
            # the value was added in Qt 5.7
            pass
        try:
            self.__errorDescriptions[
                QWebEngineCertificateError.CertificateTransparencyRequired] = \
                self.tr("Certificate Transparency was required for this"
                        " connection, but the server did not provide"
                        " information that complied with the policy.")
        except AttributeError:
            # the value was added in Qt 5.8
            pass
        
        for host, errors in errorsDict.items():
            itm = QTreeWidgetItem(self.errorsTree, [host])
            self.errorsTree.setFirstItemColumnSpanned(itm, True)
            for error in errors:
                try:
                    errorDesc = self.__errorDescriptions[error]
                except KeyError:
                    errorDesc = self.tr("No error description available.")
                QTreeWidgetItem(itm, [str(error), errorDesc])
        
        self.errorsTree.expandAll()
        for i in range(self.errorsTree.columnCount()):
            self.errorsTree.resizeColumnToContents(i)
        self.errorsTree.sortItems(0, Qt.AscendingOrder)
        
        self.__setRemoveButtons()
    
    def __setRemoveButtons(self):
        """
        Private method to set the state of the 'remove' buttons.
        """
        if self.errorsTree.topLevelItemCount() == 0:
            self.removeButton.setEnabled(False)
            self.removeAllButton.setEnabled(False)
        else:
            self.removeAllButton.setEnabled(True)
            self.removeButton.setEnabled(
                len(self.errorsTree.selectedItems()) > 0)
    
    @pyqtSlot(QPoint)
    def on_errorsTree_customContextMenuRequested(self, pos):
        """
        Private slot to show the context menu.
        
        @param pos cursor position
        @type QPoint
        """
        menu = QMenu()
        menu.addAction(
            self.tr("Remove Selected"),
            self.on_removeButton_clicked).setEnabled(
            self.errorsTree.topLevelItemCount() > 0 and
            len(self.errorsTree.selectedItems()) > 0)
        menu.addAction(
            self.tr("Remove All"),
            self.on_removeAllButton_clicked).setEnabled(
            self.errorsTree.topLevelItemCount() > 0)
        
        menu.exec_(self.errorsTree.mapToGlobal(pos))
    
    @pyqtSlot()
    def on_errorsTree_itemSelectionChanged(self):
        """
        Private slot handling the selection of entries.
        """
        self.__setRemoveButtons()
    
    @pyqtSlot()
    def on_removeButton_clicked(self):
        """
        Private slot to remove the selected items.
        """
        for itm in self.errorsTree.selectedItems():
            pitm = itm.parent()
            if pitm:
                pitm.removeChild(itm)
            else:
                index = self.errorsTree.indexOfTopLevelItem(itm)
                self.errorsTree.takeTopLevelItem(index)
            del itm
        
        # remove all hosts without an exception
        for index in range(self.errorsTree.topLevelItemCount() - 1, -1, -1):
            itm = self.errorsTree.topLevelItem(index)
            if itm.childCount() == 0:
                self.errorsTree.takeTopLevelItem(index)
                del itm
    
    @pyqtSlot()
    def on_removeAllButton_clicked(self):
        """
        Private slot to remove all entries.
        """
        self.errorsTree.clear()
    
    def getSslErrorExceptions(self):
        """
        Public method to retrieve the list of SSL error exceptions.
        
        @return error exceptions
        @rtype dict of list of int
        """
        errors = {}
        
        for index in range(self.errorsTree.topLevelItemCount()):
            itm = self.errorsTree.topLevelItem(index)
            host = itm.text(0)
            errors[host] = []
            for cindex in range(itm.childCount()):
                citm = itm.child(cindex)
                errors[host].append(int(citm.text(0)))
        
        return errors
