Helpviewer/Sync/FtpSyncHandler.py

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

# Copyright (c) 2012 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a synchronization handler using FTP.
"""

from PyQt4.QtCore import pyqtSignal, QUrl, QIODevice, QTime, QThread, QTimer, QBuffer, \
    QFileInfo
from PyQt4.QtNetwork import QFtp, QNetworkProxyQuery, QNetworkProxy, QNetworkProxyFactory

from .SyncHandler import SyncHandler

import Helpviewer.HelpWindow

import Preferences


class FtpSyncHandler(SyncHandler):
    """
    Class implementing a synchronization handler using FTP.
    
    @signal syncStatus(type_, done, message) emitted to indicate the synchronization
        status (string one of "bookmarks", "history", "passwords" or "useragents",
        boolean, string)
    @signal syncError(message) emitted for a general error with the error message (string)
    @signal syncMessage(message) emitted to send a message about synchronization (string)
    @signal syncFinished(type_, done, download) emitted after a synchronization has
        finished (string one of "bookmarks", "history", "passwords" or "useragents",
        boolean, boolean)
    """
    syncStatus = pyqtSignal(str, bool, str)
    syncError = pyqtSignal(str)
    syncMessage = pyqtSignal(str)
    syncFinished = pyqtSignal(str, bool, bool)
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent object (QObject)
        """
        super().__init__(parent)
        
        self.__state = "idle"
        self.__forceUpload = False
        
        self.__remoteFilesFound = {}
    
    def initialLoadAndCheck(self, forceUpload):
        """
        Public method to do the initial check.
        
        @keyparam forceUpload flag indicating a forced upload of the files (boolean)
        """
        if not Preferences.getHelp("SyncEnabled"):
            return
        
        self.__state = "initializing"
        self.__forceUpload = forceUpload
        
        self.__remoteFilesFound = {}
        self.__syncIDs = {}
        
        self.__idleTimer = QTimer(self)
        self.__idleTimer.setInterval(Preferences.getHelp("SyncFtpIdleTimeout") * 1000)
        self.__idleTimer.timeout.connect(self.__idleTimeout)
        
        self.__ftp = QFtp(self)
        self.__ftp.commandFinished.connect(self.__commandFinished)
        self.__ftp.listInfo.connect(self.__checkSyncFiles)
        
        # do proxy setup
        url = QUrl("ftp://{0}:{1}".format(
            Preferences.getHelp("SyncFtpServer"),
            Preferences.getHelp("SyncFtpPort")
        ))
        query = QNetworkProxyQuery(url)
        proxyList = QNetworkProxyFactory.proxyForQuery(query)
        ftpProxy = QNetworkProxy()
        for proxy in proxyList:
            if proxy.type() == QNetworkProxy.NoProxy or \
               proxy.type() == QNetworkProxy.FtpCachingProxy:
                ftpProxy = proxy
                break
        if ftpProxy.type() == QNetworkProxy.DefaultProxy:
            self.syncError.emit(self.trUtf8("No suitable proxy found."))
            return
        elif ftpProxy.type() == QNetworkProxy.FtpCachingProxy:
            self.__ftp.setProxy(ftpProxy.hostName(), ftpProxy.port())
        
        self.__ftp.connectToHost(Preferences.getHelp("SyncFtpServer"),
                                 Preferences.getHelp("SyncFtpPort"))
        self.__ftp.login(Preferences.getHelp("SyncFtpUser"),
                         Preferences.getHelp("SyncFtpPassword"))
    
    def __changeToStore(self):
        """
        Private slot to change to the storage directory.
        
        This action might cause the storage path to be created on the server.
        """
        self.__storePathList = \
            Preferences.getHelp("SyncFtpPath").replace("\\", "/").split("/")
        if self.__storePathList[0] == "":
            del self.__storePathList[0]
            self.__ftp.cd(self.__storePathList[0])
    
    def __commandFinished(self, id, error):
        """
        Private slot handling the end of a command.
        
        @param id id of the finished command (integer)
        @param error flag indicating an error situation (boolean)
        """
        if error:
            if self.__ftp.currentCommand() in [
                QFtp.ConnectToHost, QFtp.Login, QFtp.Mkdir, QFtp.List]:
                self.syncError.emit(self.__ftp.errorString())
            elif self.__ftp.currentCommand() == QFtp.Cd:
                self.__ftp.mkdir(self.__storePathList[0])
                self.__ftp.cd(self.__storePathList[0])
            else:
                if id in self.__syncIDs:
                    if self.__ftp.currentCommand() == QFtp.Get:
                        self.__syncIDs[id][1].close()
                    self.syncStatus.emit(self.__syncIDs[id][0], False,
                        self.__ftp.errorString())
                    self.syncFinished.emit(self.__syncIDs[id][0], False,
                        self.__syncIDs[id][2])
                    del self.__syncIDs[id]
                    if not self.__syncIDs:
                        self.__state = "idle"
                        self.syncMessage.emit(self.trUtf8("Synchronization finished"))
        else:
            if self.__ftp.currentCommand() == QFtp.Login:
                self.__changeToStore()
            elif self.__ftp.currentCommand() == QFtp.Cd:
                del self.__storePathList[0]
                if self.__storePathList:
                    self.__ftp.cd(self.__storePathList[0])
                else:
                    self.__storeReached()
            elif self.__ftp.currentCommand() == QFtp.List:
                self.__initialSync()
            else:
                if id in self.__syncIDs:
                    if self.__ftp.currentCommand() == QFtp.Get:
                        self.__syncIDs[id][1].close()
                        ok, error = self.writeFile(self.__syncIDs[id][1].buffer(),
                                                   self.__syncIDs[id][3],
                                                   self.__syncIDs[id][4])
                        if ok:
                            self.syncStatus.emit(self.__syncIDs[id][0], True,
                                self._messages[self.__syncIDs[id][0]]["RemoteExists"])
                        else:
                            self.syncStatus.emit(self.__syncIDs[id][0], False,
                                error)
                    self.syncFinished.emit(self.__syncIDs[id][0], True,
                        self.__syncIDs[id][2])
                    del self.__syncIDs[id]
                    if not self.__syncIDs:
                        self.__state = "idle"
                        self.syncMessage.emit(self.trUtf8("Synchronization finished"))
    
    def __storeReached(self):
        """
        Private slot executed, when the storage directory was reached.
        """
        if self.__state == "initializing":
            self.__ftp.list()
            self.__idleTimer.start()
    
    def __checkSyncFiles(self, info):
        """
        Private slot called for each entry sent by the FTP list command.
        
        @param info info about the entry (QUrlInfo)
        """
        if info.isValid() and info.isFile():
            if info.name() in self._remoteFiles.values():
                self.__remoteFilesFound[info.name()] = info.lastModified()
    
    def __downloadFile(self, type_, fileName, timestamp):
        """
        Private method to downlaod the given file.
        
        @param type_ type of the synchronization event (string one
            of "bookmarks", "history", "passwords" or "useragents")
        @param fileName name of the file to be downloaded (string)
        @param timestamp time stamp in seconds of the file to be downloaded (int)
        """
        buffer = QBuffer(self)
        buffer.open(QIODevice.WriteOnly)
        id = self.__ftp.get(self._remoteFiles[type_], buffer)
        self.__syncIDs[id] = (type_, buffer, True, fileName, timestamp)
    
    def __uploadFile(self, type_, fileName):
        """
        Private method to upload the given file.
        
        @param type_ type of the synchronization event (string one
            of "bookmarks", "history", "passwords" or "useragents")
        @param fileName name of the file to be uploaded (string)
        """
        data = self.readFile(fileName)
        if data.isEmpty():
            self.syncStatus.emit(type_, True,
                self._messages[type_]["LocalMissing"])
        else:
            id = self.__ftp.put(data, self._remoteFiles[type_])
            self.__syncIDs[id] = (type_, data, False)
    
    def __initialSyncFile(self, type_, fileName):
        """
        Private method to do the initial synchronization of the given file.
        
        @param type_ type of the synchronization event (string one
            of "bookmarks", "history", "passwords" or "useragents")
        @param fileName name of the file to be synchronized (string)
        """
        if not self.__forceUpload and \
           self._remoteFiles[type_] in self.__remoteFilesFound and \
           QFileInfo(fileName).lastModified() <= \
                self.__remoteFilesFound[self._remoteFiles[type_]]:
            self.__downloadFile(type_, fileName,
                self.__remoteFilesFound[self._remoteFiles[type_]].toTime_t())
        else:
            if self._remoteFiles[type_] not in self.__remoteFilesFound:
                self.syncStatus.emit(type_, True,
                    self._messages[type_]["RemoteMissing"])
            else:
                self.syncStatus.emit(type_, True,
                    self._messages[type_]["LocalNewer"])
            self.__uploadFile(type_, fileName)
    
    def __initialSync(self):
        """
        Private slot to do the initial synchronization.
        """
        # Bookmarks
        if Preferences.getHelp("SyncBookmarks"):
            self.__initialSyncFile("bookmarks",
                Helpviewer.HelpWindow.HelpWindow.bookmarksManager().getFileName())
        
        # History
        if Preferences.getHelp("SyncHistory"):
            self.__initialSyncFile("history",
                Helpviewer.HelpWindow.HelpWindow.historyManager().getFileName())
        
        # Passwords
        if Preferences.getHelp("SyncPasswords"):
            self.__initialSyncFile("passwords",
                Helpviewer.HelpWindow.HelpWindow.passwordManager().getFileName())
        
        # User Agent Settings
        if Preferences.getHelp("SyncUserAgents"):
            self.__initialSyncFile("useragents",
                Helpviewer.HelpWindow.HelpWindow.userAgentsManager().getFileName())
        
        self.__forceUpload = False
    
    def __syncFile(self, type_, fileName):
        """
        Private method to synchronize the given file.
        
        @param type_ type of the synchronization event (string one
            of "bookmarks", "history", "passwords" or "useragents")
        @param fileName name of the file to be synchronized (string)
        """
        if self.__state == "initializing":
            return
        
        self.__state = "uploading"
        self.syncStatus.emit(type_, True, self._messages[type_]["Uploading"])
        self.__uploadFile(type_, fileName)
    
    def syncBookmarks(self):
        """
        Public method to synchronize the bookmarks.
        """
        self.__syncFile("bookmarks",
            Helpviewer.HelpWindow.HelpWindow.bookmarksManager().getFileName())
    
    def syncHistory(self):
        """
        Public method to synchronize the history.
        """
        self.__syncFile("history",
            Helpviewer.HelpWindow.HelpWindow.historyManager().getFileName())
    
    def syncPasswords(self):
        """
        Public method to synchronize the passwords.
        """
        self.__syncFile("passwords",
            Helpviewer.HelpWindow.HelpWindow.passwordManager().getFileName())
    
    def syncUserAgents(self):
        """
        Public method to synchronize the user agents.
        """
        self.__syncFile("useragents",
            Helpviewer.HelpWindow.HelpWindow.userAgentsManager().getFileName())
    
    def shutdown(self):
        """
        Public method to shut down the handler.
        """
        if self.__idleTimer.isActive():
            self.__idleTimer.stop()
        
        t = QTime.currentTime()
        t.start()
        while t.elapsed() < 5000 and self.__ftp.hasPendingCommands():
            QThread.msleep(200)
        if self.__ftp.hasPendingCommands():
            self.__ftp.clearPendingCommands()
        if self.__ftp.currentCommand() != 0:
            self.__ftp.abort()
    
    def __idleTimeout(self):
        """
        Private slot to prevent a disconnect from the server.
        """
        self.__ftp.rawCommand("NOOP")