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

# Copyright (c) 2010 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the download manager class.
"""


from PyQt5.QtCore import (
    pyqtSlot, pyqtSignal, Qt, QModelIndex, QFileInfo, QUrl, QBasicTimer
)
from PyQt5.QtGui import QCursor, QKeySequence
from PyQt5.QtWidgets import (
    QDialog, QStyle, QFileIconProvider, QMenu, QApplication, QShortcut
)

from E5Gui import E5MessageBox
from E5Gui.E5Application import e5App

from .Ui_DownloadManager import Ui_DownloadManager

from .DownloadModel import DownloadModel
from .DownloadUtilities import speedString, timeString

from WebBrowser.WebBrowserWindow import WebBrowserWindow

from Utilities.AutoSaver import AutoSaver
import UI.PixmapCache
import Preferences
import Globals


class DownloadManager(QDialog, Ui_DownloadManager):
    """
    Class implementing the download manager.
    
    @signal downloadsCountChanged() emitted to indicate a change of the
        count of download items
    """
    RemoveNever = 0
    RemoveExit = 1
    RemoveSuccessFullDownload = 2
    
    UpdateTimerTimeout = 1000
    
    downloadsCountChanged = pyqtSignal()
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent widget (QWidget)
        """
        super(DownloadManager, self).__init__(parent)
        self.setupUi(self)
        self.setWindowFlags(Qt.Window)
        
        self.__winTaskbarButton = None
        
        self.__saveTimer = AutoSaver(self, self.save)
        
        self.__model = DownloadModel(self)
        self.__manager = WebBrowserWindow.networkManager()
        
        self.__iconProvider = None
        self.__downloads = []
        self.__downloadDirectory = ""
        self.__loaded = False
        
        self.__rowHeightMultiplier = 1.1
        
        self.setDownloadDirectory(Preferences.getUI("DownloadPath"))
        
        self.downloadsView.setShowGrid(False)
        self.downloadsView.verticalHeader().hide()
        self.downloadsView.horizontalHeader().hide()
        self.downloadsView.setAlternatingRowColors(True)
        self.downloadsView.horizontalHeader().setStretchLastSection(True)
        self.downloadsView.setModel(self.__model)
        self.downloadsView.setContextMenuPolicy(Qt.CustomContextMenu)
        self.downloadsView.customContextMenuRequested.connect(
            self.__customContextMenuRequested)
        
        self.__clearShortcut = QShortcut(QKeySequence("Ctrl+L"), self)
        self.__clearShortcut.activated.connect(self.on_cleanupButton_clicked)
        
        self.__load()
        
        self.__updateTimer = QBasicTimer()
    
    def __customContextMenuRequested(self, pos):
        """
        Private slot to handle the context menu request for the bookmarks tree.
        
        @param pos position the context menu was requested (QPoint)
        """
        menu = QMenu()
        
        selectedRowsCount = len(
            self.downloadsView.selectionModel().selectedRows())
        
        if selectedRowsCount == 1:
            row = self.downloadsView.selectionModel().selectedRows()[0].row()
            itm = self.__downloads[row]
            if itm.downloadedSuccessfully():
                menu.addAction(
                    UI.PixmapCache.getIcon("open.png"),
                    self.tr("Open"), self.__contextMenuOpen)
            elif itm.downloading():
                menu.addAction(
                    UI.PixmapCache.getIcon("stopLoading.png"),
                    self.tr("Cancel"), self.__contextMenuCancel)
                menu.addSeparator()
            menu.addAction(
                self.tr("Open Containing Folder"),
                self.__contextMenuOpenFolder)
            menu.addSeparator()
            menu.addAction(
                self.tr("Go to Download Page"),
                self.__contextMenuGotoPage)
            menu.addAction(
                self.tr("Copy Download Link"),
                self.__contextMenuCopyLink)
            menu.addSeparator()
        menu.addAction(self.tr("Select All"), self.__contextMenuSelectAll)
        if (
            selectedRowsCount > 1 or
            (selectedRowsCount == 1 and
             not self.__downloads[
                self.downloadsView.selectionModel().selectedRows()[0].row()]
                .downloading())
        ):
            menu.addSeparator()
            menu.addAction(
                self.tr("Remove From List"),
                self.__contextMenuRemoveSelected)
        
        menu.exec_(QCursor.pos())
    
    def shutdown(self):
        """
        Public method to stop the download manager.
        """
        self.save()
        self.close()
    
    def activeDownloadsCount(self):
        """
        Public method to get the number of active downloads.
        
        @return number of active downloads (integer)
        """
        count = 0
        
        for download in self.__downloads:
            if download.downloading():
                count += 1
        return count
    
    def allowQuit(self):
        """
        Public method to check, if it is ok to quit.
        
        @return flag indicating allowance to quit (boolean)
        """
        if self.activeDownloadsCount() > 0:
            res = E5MessageBox.yesNo(
                self,
                self.tr(""),
                self.tr("""There are %n downloads in progress.\n"""
                        """Do you want to quit anyway?""", "",
                        self.activeDownloadsCount()),
                icon=E5MessageBox.Warning)
            if not res:
                self.show()
                return False
        
        self.close()
        return True
    
    def __testWebBrowserView(self, view, url):
        """
        Private method to test a web browser view against an URL.
        
        @param view reference to the web browser view to be tested
        @type WebBrowserView
        @param url URL to test against
        @type QUrl
        @return flag indicating, that the view is the one for the URL
        @rtype bool
        """
        if view.tabWidget().count() < 2:
            return False
        
        page = view.page()
        if page.history().count() != 0:
            return False
        
        if (
            not page.url().isEmpty() and
            page.url().host() == url.host()
        ):
            return True
        
        requestedUrl = page.requestedUrl()
        if requestedUrl.isEmpty():
            requestedUrl = QUrl(view.tabWidget().urlBarForView(view).text())
        return requestedUrl.isEmpty() or requestedUrl.host() == url.host()
    
    def __closeDownloadTab(self, url):
        """
        Private method to close an empty tab, that was opened only for loading
        the download URL.
        
        @param url download URL
        @type QUrl
        """
        if self.__testWebBrowserView(
           WebBrowserWindow.getWindow().currentBrowser(), url):
            WebBrowserWindow.getWindow().closeCurrentBrowser()
            return
        
        for window in WebBrowserWindow.mainWindows():
            for browser in window.browsers():
                if self.__testWebBrowserView(browser, url):
                    window.closeBrowser(browser)
                    return
    
    def download(self, downloadItem):
        """
        Public method to download a file.
        
        @param downloadItem reference to the download object containing the
        download data.
        @type QWebEngineDownloadItem
        """
        url = downloadItem.url()
        if url.isEmpty():
            return
        
        self.__closeDownloadTab(url)
        
        # Safe Browsing
        from WebBrowser.SafeBrowsing.SafeBrowsingManager import (
            SafeBrowsingManager
        )
        if SafeBrowsingManager.isEnabled():
            threatLists = (
                WebBrowserWindow.safeBrowsingManager().lookupUrl(url)[0]
            )
            if threatLists:
                threatMessages = (
                    WebBrowserWindow.safeBrowsingManager()
                    .getThreatMessages(threatLists)
                )
                res = E5MessageBox.warning(
                    WebBrowserWindow.getWindow(),
                    self.tr("Suspicuous URL detected"),
                    self.tr("<p>The URL <b>{0}</b> was found in the Safe"
                            " Browsing database.</p>{1}").format(
                        url.toString(), "".join(threatMessages)),
                    E5MessageBox.StandardButtons(
                        E5MessageBox.Abort |
                        E5MessageBox.Ignore),
                    E5MessageBox.Abort)
                if res == E5MessageBox.Abort:
                    downloadItem.cancel()
                    return
        
        window = WebBrowserWindow.getWindow()
        if window:
            pageUrl = window.currentBrowser().url()
        else:
            pageUrl = QUrl()
        from .DownloadItem import DownloadItem
        itm = DownloadItem(downloadItem=downloadItem, pageUrl=pageUrl,
                           parent=self)
        self.__addItem(itm)
        
        if Preferences.getWebBrowser("DownloadManagerAutoOpen"):
            self.show()
        else:
            self.__startUpdateTimer()
    
    def show(self):
        """
        Public slot to show the download manager dialog.
        """
        self.__startUpdateTimer()
        
        super(DownloadManager, self).show()
        self.activateWindow()
        self.raise_()
    
    def __addItem(self, itm, append=False):
        """
        Private method to add a download to the list of downloads.
        
        @param itm reference to the download item
        @type DownloadItem
        @param append flag indicating to append the item
        @type bool
        """
        itm.statusChanged.connect(lambda: self.__updateRow(itm))
        itm.downloadFinished.connect(self.__finished)
        
        # insert at top of window
        if append:
            row = self.downloadsCount()
        else:
            row = 0
        self.__model.beginInsertRows(QModelIndex(), row, row)
        if append:
            self.__downloads.append(itm)
        else:
            self.__downloads.insert(0, itm)
        self.__model.endInsertRows()
        
        self.downloadsView.setIndexWidget(self.__model.index(row, 0), itm)
        icon = self.style().standardIcon(QStyle.SP_FileIcon)
        itm.setIcon(icon)
        self.downloadsView.setRowHeight(
            row, itm.sizeHint().height() * self.__rowHeightMultiplier)
        # just in case the download finished before the constructor returned
        self.__updateRow(itm)
        self.changeOccurred()
        
        self.downloadsCountChanged.emit()
    
    def __updateRow(self, itm):
        """
        Private slot to update a download item.
        
        @param itm reference to the download item
        @type DownloadItem
        """
        if itm not in self.__downloads:
            return
        
        row = self.__downloads.index(itm)
        
        if self.__iconProvider is None:
            self.__iconProvider = QFileIconProvider()
        
        icon = self.__iconProvider.icon(QFileInfo(itm.fileName()))
        if icon.isNull():
            icon = self.style().standardIcon(QStyle.SP_FileIcon)
        itm.setIcon(icon)
        
        self.downloadsView.setRowHeight(
            row,
            itm.minimumSizeHint().height() * self.__rowHeightMultiplier)
        
        remove = False
        
        if (
            itm.downloadedSuccessfully() and
            self.removePolicy() == DownloadManager.RemoveSuccessFullDownload
        ):
            remove = True
        
        if remove:
            self.__model.removeRow(row)
        
        self.cleanupButton.setEnabled(
            (self.downloadsCount() - self.activeDownloadsCount()) > 0)
        
        # record the change
        self.changeOccurred()
    
    def removePolicy(self):
        """
        Public method to get the remove policy.
        
        @return remove policy (integer)
        """
        return Preferences.getWebBrowser("DownloadManagerRemovePolicy")
    
    def setRemovePolicy(self, policy):
        """
        Public method to set the remove policy.
        
        @param policy policy to be set
            (DownloadManager.RemoveExit, DownloadManager.RemoveNever,
             DownloadManager.RemoveSuccessFullDownload)
        """
        assert policy in (DownloadManager.RemoveExit,
                          DownloadManager.RemoveNever,
                          DownloadManager.RemoveSuccessFullDownload)
        
        if policy == self.removePolicy():
            return
        
        Preferences.setWebBrowser("DownloadManagerRemovePolicy", self.policy)
    
    def save(self):
        """
        Public method to save the download settings.
        """
        if not self.__loaded:
            return
        
        Preferences.setWebBrowser("DownloadManagerSize", self.size())
        Preferences.setWebBrowser("DownloadManagerPosition", self.pos())
        if self.removePolicy() == DownloadManager.RemoveExit:
            return
        
        from WebBrowser.WebBrowserWindow import WebBrowserWindow
        if WebBrowserWindow.isPrivate():
            return
        
        downloads = []
        for download in self.__downloads:
            downloads.append(download.getData())
        Preferences.setWebBrowser("DownloadManagerDownloads", downloads)
    
    def __load(self):
        """
        Private method to load the download settings.
        """
        if self.__loaded:
            return
        
        size = Preferences.getWebBrowser("DownloadManagerSize")
        if size.isValid():
            self.resize(size)
        pos = Preferences.getWebBrowser("DownloadManagerPosition")
        self.move(pos)
        
        from WebBrowser.WebBrowserWindow import WebBrowserWindow
        if not WebBrowserWindow.isPrivate():
            downloads = Preferences.getWebBrowser("DownloadManagerDownloads")
            for download in downloads:
                if (
                    not download["URL"].isEmpty() and
                    bool(download["Location"])
                ):
                    from .DownloadItem import DownloadItem
                    itm = DownloadItem(parent=self)
                    itm.setData(download)
                    self.__addItem(itm, append=True)
            self.cleanupButton.setEnabled(
                (self.downloadsCount() - self.activeDownloadsCount()) > 0)
        
        self.__loaded = True
        
        self.downloadsCountChanged.emit()
    
    def closeEvent(self, evt):
        """
        Protected event handler for the close event.
        
        @param evt reference to the close event
        @type QCloseEvent
        """
        self.save()
    
    def cleanup(self):
        """
        Public slot to cleanup the downloads.
        """
        self.on_cleanupButton_clicked()
    
    @pyqtSlot()
    def on_cleanupButton_clicked(self):
        """
        Private slot to cleanup the downloads.
        """
        if self.downloadsCount() == 0:
            return
        
        self.__model.removeRows(0, self.downloadsCount())
        if (
            self.downloadsCount() == 0 and
            self.__iconProvider is not None
        ):
            self.__iconProvider = None
        
        self.changeOccurred()
        
        self.downloadsCountChanged.emit()
    
    def __finished(self, success):
        """
        Private slot to handle a finished download.
        
        @param success flag indicating a successful download
        @type bool
        """
        if self.isVisible():
            QApplication.alert(self)
        
        self.downloadsCountChanged.emit()
        
        if self.activeDownloadsCount() == 0:
            # all active downloads are done
            if success and e5App().activeWindow() is not self:
                if WebBrowserWindow.notificationsEnabled():
                    WebBrowserWindow.showNotification(
                        UI.PixmapCache.getPixmap("downloads48.png"),
                        self.tr("Downloads finished"),
                        self.tr("All files have been downloaded.")
                    )
                if not Preferences.getWebBrowser("DownloadManagerAutoClose"):
                    self.raise_()
                    self.activateWindow()
            
            self.__stopUpdateTimer()
            self.infoLabel.clear()
            self.setWindowTitle(self.tr("Download Manager"))
            if Globals.isWindowsPlatform():
                self.__taskbarButton().progress().hide()
            
            if Preferences.getWebBrowser("DownloadManagerAutoClose"):
                self.close()
    
    def setDownloadDirectory(self, directory):
        """
        Public method to set the current download directory.
        
        @param directory current download directory (string)
        """
        self.__downloadDirectory = directory
        if self.__downloadDirectory != "":
            self.__downloadDirectory += "/"
    
    def downloadDirectory(self):
        """
        Public method to get the current download directory.
        
        @return current download directory (string)
        """
        return self.__downloadDirectory
    
    def downloadsCount(self):
        """
        Public method to get the number of downloads.
        
        @return number of downloads
        @rtype int
        """
        return len(self.__downloads)
    
    def downloads(self):
        """
        Public method to get a reference to the downloads.
        
        @return reference to the downloads (list of DownloadItem)
        """
        return self.__downloads
    
    def changeOccurred(self):
        """
        Public method to signal a change.
        """
        self.__saveTimer.changeOccurred()
    
    def __taskbarButton(self):
        """
        Private method to get a reference to the task bar button (Windows
        only).
        
        @return reference to the task bar button
        @rtype QWinTaskbarButton or None
        """
        if Globals.isWindowsPlatform():
            from PyQt5.QtWinExtras import QWinTaskbarButton
            if self.__winTaskbarButton is None:
                window = WebBrowserWindow.mainWindow()
                self.__winTaskbarButton = QWinTaskbarButton(
                    window.windowHandle())
                self.__winTaskbarButton.progress().setRange(0, 100)
        
        return self.__winTaskbarButton
    
    def timerEvent(self, evt):
        """
        Protected event handler for timer events.
        
        @param evt reference to the timer event
        @type QTimerEvent
        """
        if evt.timerId() == self.__updateTimer.timerId():
            if self.activeDownloadsCount() == 0:
                self.__stopUpdateTimer()
                self.infoLabel.clear()
                self.setWindowTitle(self.tr("Download Manager"))
                if Globals.isWindowsPlatform():
                    self.__taskbarButton().progress().hide()
            else:
                progresses = []
                for itm in self.__downloads:
                    if (
                        itm is None or
                        itm.downloadCanceled() or
                        not itm.downloading()
                    ):
                        continue
                    
                    progresses.append((
                        itm.downloadProgress(),
                        itm.remainingTime(),
                        itm.currentSpeed()
                    ))
                
                if not progresses:
                    return
                
                remaining = 0
                progress = 0
                speed = 0.0
                
                for progressData in progresses:
                    if progressData[1] > remaining:
                        remaining = progressData[1]
                    progress += progressData[0]
                    speed += progressData[2]
                progress = progress / len(progresses)
                
                if self.isVisible():
                    self.infoLabel.setText(self.tr(
                        "{0}% of %n file(s) ({1}) {2}", "",
                        len(progresses)).format(
                        progress,
                        speedString(speed),
                        timeString(remaining),
                    ))
                    self.setWindowTitle(self.tr("{0}% - Download Manager"))
                
                if Globals.isWindowsPlatform():
                    self.__taskbarButton().progress().show()
                    self.__taskbarButton().progress().setValue(progress)
        
        super(DownloadManager, self).timerEvent(evt)
    
    def __startUpdateTimer(self):
        """
        Private slot to start the update timer.
        """
        if self.activeDownloadsCount() and not self.__updateTimer.isActive():
            self.__updateTimer.start(DownloadManager.UpdateTimerTimeout, self)
    
    def __stopUpdateTimer(self):
        """
        Private slot to stop the update timer.
        """
        self.__updateTimer.stop()
    
    ###########################################################################
    ## Context menu related methods below
    ###########################################################################
    
    def __currentItem(self):
        """
        Private method to get a reference to the current item.
        
        @return reference to the current item (DownloadItem)
        """
        index = self.downloadsView.currentIndex()
        if index and index.isValid():
            row = index.row()
            return self.__downloads[row]
        
        return None
    
    def __contextMenuOpen(self):
        """
        Private method to open the downloaded file.
        """
        itm = self.__currentItem()
        if itm is not None:
            itm.openFile()
    
    def __contextMenuOpenFolder(self):
        """
        Private method to open the folder containing the downloaded file.
        """
        itm = self.__currentItem()
        if itm is not None:
            itm.openFolder()
    
    def __contextMenuCancel(self):
        """
        Private method to cancel the current download.
        """
        itm = self.__currentItem()
        if itm is not None:
            itm.cancelDownload()
    
    def __contextMenuGotoPage(self):
        """
        Private method to open the download page.
        """
        itm = self.__currentItem()
        if itm is not None:
            url = itm.getPageUrl()
            WebBrowserWindow.mainWindow().openUrl(url, "")
    
    def __contextMenuCopyLink(self):
        """
        Private method to copy the download link to the clipboard.
        """
        itm = self.__currentItem()
        if itm is not None:
            url = itm.getPageUrl().toDisplayString(QUrl.FullyDecoded)
            QApplication.clipboard().setText(url)
    
    def __contextMenuSelectAll(self):
        """
        Private method to select all downloads.
        """
        self.downloadsView.selectAll()
    
    def __contextMenuRemoveSelected(self):
        """
        Private method to remove the selected downloads from the list.
        """
        self.downloadsView.removeSelected()
