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

# Copyright (c) 2017 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to configure safe browsing support.
"""


from PyQt5.QtCore import pyqtSlot, Qt, QUrl, QDateTime
from PyQt5.QtWidgets import (
    QDialog, QDialogButtonBox, QAbstractButton, QApplication
)

from E5Gui import E5MessageBox

from .Ui_SafeBrowsingDialog import Ui_SafeBrowsingDialog

import UI.PixmapCache
import Preferences


class SafeBrowsingDialog(QDialog, Ui_SafeBrowsingDialog):
    """
    Class implementing a dialog to configure safe browsing support.
    """
    def __init__(self, manager, parent=None):
        """
        Constructor
        
        @param manager reference to the safe browsing manager
        @type SafeBrowsingManager
        @param parent reference to the parent widget
        @type QWidget
        """
        super(SafeBrowsingDialog, self).__init__(parent)
        self.setupUi(self)
        self.setWindowFlags(Qt.Window)
        
        self.__manager = manager
        self.__manager.progressMessage.connect(self.__setProgressMessage)
        self.__manager.progress.connect(self.__setProgress)
        
        self.iconLabel.setPixmap(
            UI.PixmapCache.getPixmap("safeBrowsing48.png"))
        
        self.__gsbHelpDialog = None
        
        self.__enabled = Preferences.getWebBrowser("SafeBrowsingEnabled")
        self.__apiKey = Preferences.getWebBrowser("SafeBrowsingApiKey")
        self.__filterPlatform = Preferences.getWebBrowser(
            "SafeBrowsingFilterPlatform")
        self.__automaticUpdate = Preferences.getWebBrowser(
            "SafeBrowsingAutoUpdate")
        self.__useLookupApi = Preferences.getWebBrowser(
            "SafeBrowsingUseLookupApi")
        
        self.buttonBox.setFocus()
        
        msh = self.minimumSizeHint()
        self.resize(max(self.width(), msh.width()), msh.height())
    
    def show(self):
        """
        Public slot to show the dialog.
        """
        self.gsbGroupBox.setChecked(self.__enabled)
        self.gsbApiKeyEdit.setText(self.__apiKey)
        self.gsbFilterPlatformCheckBox.setChecked(self.__filterPlatform)
        self.gsbAutoUpdateCheckBox.setChecked(self.__automaticUpdate)
        self.gsbLookupCheckBox.setChecked(self.__useLookupApi)
        
        self.__updateCacheButtons()
        
        super(SafeBrowsingDialog, self).show()
    
    @pyqtSlot()
    def on_gsbHelpButton_clicked(self):
        """
        Private slot to show some help text "How to create a safe
        browsing API key.".
        """
        if self.__gsbHelpDialog is None:
            from E5Gui.E5SimpleHelpDialog import E5SimpleHelpDialog
            from . import SafeBrowsingHelp
            
            helpStr = SafeBrowsingHelp()
            self.__gsbHelpDialog = E5SimpleHelpDialog(
                title=self.tr("Google Safe Browsing API Help"),
                helpStr=helpStr, parent=self)
        
        self.__gsbHelpDialog.show()
    
    @pyqtSlot(QAbstractButton)
    def on_buttonBox_clicked(self, button):
        """
        Private slot called by a button of the button box clicked.
        
        @param button button that was clicked (QAbstractButton)
        """
        if button == self.buttonBox.button(QDialogButtonBox.Close):
            self.close()
    
    @pyqtSlot()
    def __save(self):
        """
        Private slot to save the configuration.
        
        @return flag indicating success
        @rtype bool
        """
        self.__enabled = self.gsbGroupBox.isChecked()
        self.__apiKey = self.gsbApiKeyEdit.text()
        self.__filterPlatform = self.gsbFilterPlatformCheckBox.isChecked()
        self.__automaticUpdate = self.gsbAutoUpdateCheckBox.isChecked()
        self.__useLookupApi = self.gsbLookupCheckBox.isChecked()
        
        Preferences.setWebBrowser("SafeBrowsingEnabled", self.__enabled)
        Preferences.setWebBrowser("SafeBrowsingApiKey", self.__apiKey)
        Preferences.setWebBrowser("SafeBrowsingFilterPlatform",
                                  self.__filterPlatform)
        Preferences.setWebBrowser("SafeBrowsingAutoUpdate",
                                  self.__automaticUpdate)
        Preferences.setWebBrowser("SafeBrowsingUseLookupApi",
                                  self.__useLookupApi)
        
        self.__manager.configurationChanged()
        
        self.__updateCacheButtons()
        
        return True
    
    def closeEvent(self, evt):
        """
        Protected method to handle close events.
        
        @param evt reference to the close event
        @type QCloseEvent
        """
        if self.__okToClose():
            evt.accept()
        else:
            evt.ignore()
    
    def __isModified(self):
        """
        Private method to check, if the dialog contains modified data.
        
        @return flag indicating the presence of modified data
        @rtype bool
        """
        return (
            (self.__enabled != self.gsbGroupBox.isChecked()) or
            (self.__apiKey != self.gsbApiKeyEdit.text()) or
            (self.__filterPlatform !=
                self.gsbFilterPlatformCheckBox.isChecked()) or
            (self.__automaticUpdate !=
                self.gsbAutoUpdateCheckBox.isChecked()) or
            (self.__useLookupApi != self.gsbLookupCheckBox.isChecked())
        )
    
    def __okToClose(self):
        """
        Private method to check, if it is safe to close the dialog.
        
        @return flag indicating safe to close
        @rtype bool
        """
        QApplication.restoreOverrideCursor()
        if self.__isModified():
            res = E5MessageBox.okToClearData(
                self,
                self.tr("Safe Browsing Management"),
                self.tr("""The dialog contains unsaved changes."""),
                self.__save)
            if not res:
                return False
        return True
    
    def __updateCacheButtons(self):
        """
        Private method to set enabled state of the cache buttons.
        """
        enable = self.__enabled and bool(self.__apiKey)
        
        self.updateCacheButton.setEnabled(enable)
        self.clearCacheButton.setEnabled(enable)
        
        self.showUpdateTimeButton.setEnabled(enable and self.__automaticUpdate)
    
    @pyqtSlot()
    def on_updateCacheButton_clicked(self):
        """
        Private slot to update the local cache database.
        """
        E5MessageBox.information(
            self,
            self.tr("Update Safe Browsing Cache"),
            self.tr("""Updating the Safe Browsing cache might be a lengthy"""
                    """ operation. Please be patient!"""))
        
        QApplication.setOverrideCursor(Qt.WaitCursor)
        ok, error = self.__manager.updateHashPrefixCache()
        self.__resetProgress()
        QApplication.restoreOverrideCursor()
        if not ok:
            if error:
                E5MessageBox.critical(
                    self,
                    self.tr("Update Safe Browsing Cache"),
                    self.tr("""<p>Updating the Safe Browsing cache failed."""
                            """</p><p>Reason: {0}</p>""").format(error))
            else:
                E5MessageBox.critical(
                    self,
                    self.tr("Update Safe Browsing Cache"),
                    self.tr("""<p>Updating the Safe Browsing cache failed."""
                            """</p>"""))
    
    @pyqtSlot()
    def on_clearCacheButton_clicked(self):
        """
        Private slot to clear the local cache database.
        """
        res = E5MessageBox.yesNo(
            self,
            self.tr("Clear Safe Browsing Cache"),
            self.tr("""Do you really want to clear the Safe Browsing cache?"""
                    """ Re-populating it might take some time."""))
        if res:
            QApplication.setOverrideCursor(Qt.WaitCursor)
            self.__manager.fullCacheCleanup()
            QApplication.restoreOverrideCursor()
    
    @pyqtSlot(str, int)
    def __setProgressMessage(self, message, maximum):
        """
        Private slot to set the progress message and the maximum value.
        
        @param message progress message to be set
        @type str
        @param maximum maximum value to be set
        @type int
        """
        self.progressLabel.setText(message)
        self.progressBar.setMaximum(maximum)
        self.progressBar.setValue(0)
    
    @pyqtSlot(int)
    def __setProgress(self, value):
        """
        Private slot to set the progress value.
        
        @param value progress value to be set
        @type int
        """
        if bool(self.progressLabel.text()):
            self.progressBar.setValue(value)
    
    def __resetProgress(self):
        """
        Private method to reset the progress info.
        """
        self.progressLabel.clear()
        self.progressBar.setMaximum(100)
        self.progressBar.setValue(0)
    
    @pyqtSlot(str)
    def on_urlEdit_textChanged(self, text):
        """
        Private slot to handle changes of the entered URL text.
        
        @param text entered URL text
        @type str
        """
        url = QUrl.fromUserInput(text)
        enable = (
            url.isValid() and
            bool(url.scheme()) and
            url.scheme() not in self.__manager.getIgnoreSchemes()
        )
        self.urlCheckButton.setEnabled(enable)
    
    @pyqtSlot()
    def on_urlCheckButton_clicked(self):
        """
        Private slot to check the entered URL.
        """
        # Malicious URL for testing:
        # http://malware.testing.google.test/testing/malware/*
        # http://ianfette.org
        #
        urlStr = self.urlEdit.text()
        url = QUrl.fromUserInput(urlStr)
        threatLists, error = self.__manager.lookupUrl(url)
        
        if error:
            E5MessageBox.warning(
                self,
                self.tr("Check URL"),
                self.tr("<p>The Google Safe Browsing Server reported an"
                        " error.</p><p>{0}</p>").format(error)
            )
        elif threatLists:
            threatMessages = self.__manager.getThreatMessages(threatLists)
            E5MessageBox.warning(
                self,
                self.tr("Check URL"),
                self.tr("<p>The URL <b>{0}</b> was found in the Safe"
                        " Browsing Database.</p>{1}").format(
                    urlStr, "".join(threatMessages))
            )
        else:
            E5MessageBox.information(
                self,
                self.tr("Check URL"),
                self.tr("<p>The URL <b>{0}</b> was not found in the Safe"
                        " Browsing Database and may be considered safe."
                        "</p>")
                .format(urlStr)
            )
    
    @pyqtSlot()
    def on_saveButton_clicked(self):
        """
        Private slot to save the configuration data.
        """
        self.__save()
    
    @pyqtSlot()
    def on_showUpdateTimeButton_clicked(self):
        """
        Private slot to show the time of the next automatic threat list update.
        """
        nextUpdateDateTime = Preferences.getWebBrowser(
            "SafeBrowsingUpdateDateTime")
        if (
            not nextUpdateDateTime.isValid() or
            nextUpdateDateTime <= QDateTime.currentDateTime()
        ):
            message = self.tr("The next automatic threat list update will be"
                              " done now.")
        else:
            message = self.tr("<p>The next automatic threat list update will"
                              " be done at <b>{0}</b>.</p>").format(
                nextUpdateDateTime.toString("yyyy-MM-dd, HH:mm:ss"))
        
        E5MessageBox.information(
            self,
            self.tr("Update Time"),
            message)
