# -*- coding: utf-8 -*-
"""novelWriter GUI Main Window

 novelWriter – GUI Main Window
===============================
 Class holding the main window

 File History:
 Created: 2018-09-22 [0.0.1]

 This file is a part of novelWriter
 Copyright 2020, Veronica Berglyd Olsen

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program. If not, see <https://www.gnu.org/licenses/>.
"""

import logging
import nw

from os import path
from datetime import datetime
from time import time

from PyQt5.QtCore import Qt, QTimer
from PyQt5.QtGui import QIcon, QPixmap, QColor, QKeySequence, QCursor
from PyQt5.QtWidgets import (
    qApp, QMainWindow, QVBoxLayout, QFrame, QSplitter, QFileDialog, QShortcut,
    QMessageBox, QDialog, QTabWidget
)

from nw.gui import (
    GuiMainMenu, GuiMainStatus, GuiTheme, GuiDocTree, GuiDocEditor,
    GuiDocViewer, GuiDocDetails, GuiSearchBar, GuiNoticeBar, GuiDocViewDetails,
    GuiConfigEditor, GuiProjectEditor, GuiItemEditor, GuiProjectOutline,
    GuiSessionLogView, GuiDocMerge, GuiDocSplit, GuiProjectLoad, GuiBuildNovel
)
from nw.core import NWProject, NWDoc, NWIndex
from nw.constants import nwFiles, nwItemType, nwAlert

logger = logging.getLogger(__name__)

class GuiMain(QMainWindow):

    def __init__(self):
        QMainWindow.__init__(self)

        logger.info("Starting %s" % nw.__package__)
        logger.debug("Initialising GUI ...")
        self.mainConf   = nw.CONFIG

        # Some runtime info useful for debugging
        logger.info("OS: %s" % self.mainConf.osType)
        logger.info("Kernel: %s" % self.mainConf.kernelVer)
        logger.info("Host: %s" % self.mainConf.hostName)
        logger.info("Qt5 Version: %s (%d)" % (
            self.mainConf.verQtString, self.mainConf.verQtValue)
        )
        logger.info("PyQt5 Version: %s (%d)" % (
            self.mainConf.verPyQtString, self.mainConf.verPyQtValue)
        )
        logger.info("Python Version: %s (0x%x)" % (
            self.mainConf.verPyString, self.mainConf.verPyHexVal)
        )

        # Core Classes and settings
        self.theTheme   = GuiTheme(self)
        self.theProject = NWProject(self)
        self.theIndex   = NWIndex(self.theProject, self)
        self.hasProject = False
        self.isZenMode  = False

        # Prepare main window
        self.resize(*self.mainConf.winGeometry)
        self._setWindowTitle()
        self.setWindowIcon(QIcon(self.mainConf.appIcon))

        # Build the GUI
        ################

        # Main GUI Elements
        self.statusBar = GuiMainStatus(self)
        self.noticeBar = GuiNoticeBar(self)
        self.treeView  = GuiDocTree(self, self.theProject)
        self.docEditor = GuiDocEditor(self, self.theProject)
        self.docViewer = GuiDocViewer(self, self.theProject)
        self.viewMeta  = GuiDocViewDetails(self, self.theProject)
        self.searchBar = GuiSearchBar(self)
        self.treeMeta  = GuiDocDetails(self, self.theProject)
        self.projView  = GuiProjectOutline(self, self.theProject)
        self.mainMenu  = GuiMainMenu(self, self.theProject)

        # Minor Gui Elements
        self.statusIcons = []
        self.importIcons = []

        # Assemble Main Window
        self.treePane = QFrame()
        self.treeBox = QVBoxLayout()
        self.treeBox.setContentsMargins(0,0,0,0)
        self.treeBox.addWidget(self.treeView)
        self.treeBox.addWidget(self.treeMeta)
        self.treePane.setLayout(self.treeBox)

        self.editPane = QFrame()
        self.docEdit = QVBoxLayout()
        self.docEdit.setContentsMargins(0,0,0,0)
        self.docEdit.setSpacing(2)
        self.docEdit.addWidget(self.searchBar)
        self.docEdit.addWidget(self.noticeBar)
        self.docEdit.addWidget(self.docEditor)
        self.editPane.setLayout(self.docEdit)

        self.viewPane = QFrame()
        self.docView = QVBoxLayout()
        self.docView.setContentsMargins(0,0,0,0)
        self.docView.setSpacing(2)
        self.docView.addWidget(self.docViewer)
        self.docView.addWidget(self.viewMeta)
        self.docView.setStretch(0, 1)
        self.viewPane.setLayout(self.docView)

        self.splitView = QSplitter(Qt.Horizontal)
        self.splitView.setOpaqueResize(False)
        self.splitView.addWidget(self.editPane)
        self.splitView.addWidget(self.viewPane)

        self.splitOutline = QSplitter(Qt.Vertical)
        self.splitOutline.addWidget(self.projView)

        self.tabWidget = QTabWidget()
        self.tabWidget.setTabPosition(QTabWidget.East)
        self.tabWidget.setStyleSheet("QTabWidget::pane {border: 0;}")
        self.tabWidget.addTab(self.splitView,    "Editor")
        self.tabWidget.addTab(self.splitOutline, "Outline")
        self.tabWidget.currentChanged.connect(self._mainTabChanged)

        self.splitMain = QSplitter(Qt.Horizontal)
        self.splitMain.setContentsMargins(4,4,4,4)
        self.splitMain.setOpaqueResize(False)
        self.splitMain.addWidget(self.treePane)
        self.splitMain.addWidget(self.tabWidget)
        self.splitMain.setSizes(self.mainConf.mainPanePos)

        self.setCentralWidget(self.splitMain)

        self.idxTree   = self.splitMain.indexOf(self.treePane)
        self.idxMain   = self.splitMain.indexOf(self.tabWidget)
        self.idxEditor = self.splitView.indexOf(self.editPane)
        self.idxViewer = self.splitView.indexOf(self.viewPane)

        self.idxTabEdit = self.tabWidget.indexOf(self.splitView)
        self.idxTabProj = self.tabWidget.indexOf(self.splitOutline)

        self.splitMain.setCollapsible(self.idxTree, False)
        self.splitMain.setCollapsible(self.idxMain, False)
        self.splitView.setCollapsible(self.idxEditor, False)
        self.splitView.setCollapsible(self.idxViewer, True)

        self.viewPane.setVisible(False)
        self.searchBar.setVisible(False)

        # Build the Tree View
        self.treeView.itemSelectionChanged.connect(self._treeSingleClick)
        self.treeView.itemDoubleClicked.connect(self._treeDoubleClick)
        self.rebuildTree()

        # Set Main Window Elements
        self.setMenuBar(self.mainMenu)
        self.setStatusBar(self.statusBar)
        self.statusBar.setStatus("Ready")

        # Finalise Initialisation
        ##########################

        # Set Up Autosaving Project Timer
        self.asProjTimer = QTimer()
        self.asProjTimer.timeout.connect(self._autoSaveProject)

        # Set Up Autosaving Document Timer
        self.asDocTimer = QTimer()
        self.asDocTimer.timeout.connect(self._autoSaveDocument)

        # Shortcuts and Actions
        self._connectMenuActions()
        keyReturn = QShortcut(self.treeView)
        keyReturn.setKey(QKeySequence(Qt.Key_Return))
        keyReturn.activated.connect(self._treeKeyPressReturn)
        keyEscape = QShortcut(self)
        keyEscape.setKey(QKeySequence(Qt.Key_Escape))
        keyEscape.activated.connect(self._keyPressEscape)

        # Forward Functions
        self.setStatus = self.statusBar.setStatus
        self.setProjectStatus = self.statusBar.setProjectStatus

        if self.mainConf.showGUI:
            self.show()

        # Check that config loaded fine
        self.reportConfErr()

        self.initMain()
        self.asProjTimer.start()
        self.asDocTimer.start()
        self.statusBar.clearStatus()

        self.showNormal()
        if self.mainConf.isFullScreen:
            self.toggleFullScreenMode()

        logger.debug("GUI initialisation complete")

        # Check if a project path was provided at command line, and if
        # not, open the project manager instead.
        if self.mainConf.cmdOpen is not None:
            logger.debug("Opening project from additional command line option")
            self.openProject(self.mainConf.cmdOpen)
        else:
            self.manageProjects()

        return

    def clearGUI(self):
        """Wrapper function to clear all sub-elements of the main GUI.
        """
        self.treeView.clearTree()
        self.docEditor.clearEditor()
        self.closeDocViewer()
        self.statusBar.clearStatus()
        return True

    def initMain(self):
        """Initialise elements that depend on user settings.
        """
        self.asProjTimer.setInterval(int(self.mainConf.autoSaveProj*1000))
        self.asDocTimer.setInterval(int(self.mainConf.autoSaveDoc*1000))
        return True

    ##
    #  Project Actions
    ##

    def manageProjects(self):
        """Opens the projects dialog for selecting either existing
        projects from a cache of recently opened projects, or provide a
        browse button for projects not yet cached.
        """
        if not self.mainConf.showGUI:
            return False

        dlgProj = GuiProjectLoad(self)
        dlgProj.exec_()
        if dlgProj.result() == QDialog.Accepted:
            if dlgProj.openState == GuiProjectLoad.OPEN_STATE:
                self.openProject(dlgProj.openPath)
            elif dlgProj.openState == GuiProjectLoad.BROWSE_STATE:
                self.openProject(dlgProj.openPath)
            elif dlgProj.openState == GuiProjectLoad.NEW_STATE:
                self.newProject()

        return True

    def newProject(self, projPath=None, forceNew=False):
        """Create new project with a few default files and folders.
        """

        if self.hasProject:
            msgBox = QMessageBox()
            msgRes = msgBox.warning(
                self, "New Project",
                "Please close the current project before making a new one."
            )
            return False

        if projPath is None:
            projPath = self.newProjectDialog()
        if projPath is None:
            return False

        if path.isfile(path.join(projPath,self.theProject.projFile)) and not forceNew:
            msgBox = QMessageBox()
            msgRes = msgBox.critical(
                self, "New Project",
                "A project already exists in that location. Please choose another folder."
            )
            return False

        logger.info("Creating new project")
        self.theProject.newProject()
        self.theProject.setProjectPath(projPath)
        self.rebuildTree()
        self.saveProject()
        self.hasProject = True
        self.statusBar.setRefTime(self.theProject.projOpened)

        return True

    def closeProject(self, isYes=False):
        """Closes the project if one is open. isYes is passed on from
        the close application event so the user doesn't get prompted
        twice.
        """
        if not self.hasProject:
            # There is no project loaded, everything OK
            return True

        if self.mainConf.showGUI and not isYes:
            msgBox = QMessageBox()
            msgRes = msgBox.question(
                self, "Close Project", "Save changes and close current project?"
            )
            if msgRes != QMessageBox.Yes:
                return False

        if self.docEditor.docChanged:
            self.saveDocument()

        if self.theProject.projAltered:
            saveOK   = self.saveProject()
            doBackup = False
            if self.theProject.doBackup and self.mainConf.backupOnClose:
                doBackup = True
                if self.mainConf.showGUI and self.mainConf.askBeforeBackup:
                    msgBox = QMessageBox()
                    msgRes = msgBox.question(
                        self, "Backup Project", "Backup current project?"
                    )
                    if msgRes != QMessageBox.Yes:
                        doBackup = False
            if doBackup:
                self.theProject.zipIt(False)
        else:
            saveOK = True

        if saveOK:
            self.closeDocument()
            self.projView.closeOutline()
            self.theProject.closeProject()
            self.theIndex.clearIndex()
            self.clearGUI()
            self.hasProject = False
            self.tabWidget.setCurrentWidget(self.splitView)

        return saveOK

    def openProject(self, projFile=None):
        """Open a project. The parameter projFile is passed from the
        open recent projects menu, so it can be set. If not, we pop the
        dialog.
        """
        if projFile is None:
            projFile = self.openProjectDialog()
        if projFile is None:
            return False

        # Make sure any open project is cleared out first before we load
        # another one
        if not self.closeProject():
            return False

        # Switch main tab to editor view
        self.tabWidget.setCurrentWidget(self.splitView)

        # Try to open the project
        if not self.theProject.openProject(projFile):
            if self.theProject.lockedBy is not None:
                if self.mainConf.showGUI:
                    try:
                        lockDetails = (
                            "<br><br>The project was locked by the computer "
                            "'%s' (%s %s), last active on %s"
                        ) % (
                            self.theProject.lockedBy[0],
                            self.theProject.lockedBy[1],
                            self.theProject.lockedBy[2],
                            datetime.fromtimestamp(
                                int(self.theProject.lockedBy[3])
                            ).strftime("%x %X")
                        )
                    except:
                        lockDetails = ""

                    msgBox = QMessageBox()
                    msgRes = msgBox.warning(
                        self, "Project Locked", (
                            "The project is already open by another instance of %s, and is "
                            "therefore locked. Override lock and continue anyway?<br><br>"
                            "Note: If the program or the computer previously crashed, the lock "
                            "can safely be overridden. If, however, another instance of %s has "
                            "the project open, overriding the lock may corrupt the project, and "
                            "is not recommended.%s"
                        ) % (nw.__package__, nw.__package__, lockDetails),
                        QMessageBox.Yes | QMessageBox.No, QMessageBox.No
                    )
                    if msgRes == QMessageBox.Yes:
                        if not self.theProject.openProject(projFile, overrideLock=True):
                            return False
                    else:
                        return False
            else:
                return False

        # Project is loaded
        self.hasProject = True

        # Load the tag index
        self.theIndex.loadIndex()

        # Update GUI
        self._setWindowTitle(self.theProject.projName)
        self.rebuildTree()
        self.docEditor.setDictionaries()
        self.docEditor.setSpellCheck(self.theProject.spellCheck)
        self.mainMenu.setAutoOutline(self.theProject.autoOutline)
        self.statusBar.setRefTime(self.theProject.projOpened)

        # Restore previously open documents, if any
        if self.theProject.lastEdited is not None:
            self.openDocument(self.theProject.lastEdited)
        if self.theProject.lastViewed is not None:
            self.viewDocument(self.theProject.lastViewed)

        # Check if we need to rebuild the index
        if self.theIndex.indexBroken:
            self.rebuildIndex()

        return True

    def saveProject(self, autoSave=False):
        """Save the current project.
        """
        if not self.hasProject:
            return False

        # If the project is new, it may not have a path, so we need one
        if self.theProject.projPath is None:
            projPath = self.saveProjectDialog()
            self.theProject.setProjectPath(projPath)
        if self.theProject.projPath is None:
            return False

        self.treeView.saveTreeOrder()
        self.theProject.saveProject(autoSave)
        self.theIndex.saveIndex()

        return True

    ##
    #  Document Actions
    ##

    def closeDocument(self):
        """Close the document and clear the editor and title field.
        """
        if self.hasProject:
            if self.docEditor.docChanged:
                self.saveDocument()
            self.docEditor.clearEditor()
        return True

    def openDocument(self, tHandle, tLine=None):
        """Open a specific document, optionally at a given line.
        """
        if self.hasProject:
            self.closeDocument()
            self.tabWidget.setCurrentWidget(self.splitView)
            if self.docEditor.loadText(tHandle, tLine):
                self.docEditor.setFocus()
                self.theProject.setLastEdited(tHandle)
                self.treeView.setSelectedHandle(tHandle)
            else:
                return False
        return True

    def saveDocument(self):
        if self.hasProject:
            self.docEditor.saveText()
        return True

    def viewDocument(self, tHandle=None):
        """Load a document for viewing in the view panel.
        """

        if tHandle is None:
            tHandle = self.treeView.getSelectedHandle()
        if tHandle is None:
            logger.debug("No document selected, trying editor document")
            tHandle = self.docEditor.theHandle
        if tHandle is None:
            logger.debug("No document selected, trying last viewed")
            tHandle = self.theProject.lastViewed
        if tHandle is None:
            logger.debug("No document selected, giving up")
            return False

        # Make sure main tab is in Editor view
        self.tabWidget.setCurrentWidget(self.splitView)

        if self.docViewer.loadText(tHandle) and not self.viewPane.isVisible():
            bPos = self.splitMain.sizes()
            self.viewPane.setVisible(True)
            vPos = [0,0]
            vPos[0] = int(bPos[1]/2)
            vPos[1] = bPos[1]-vPos[0]
            self.splitView.setSizes(vPos)

        return True

    def importDocument(self):
        """Import the text contained in an out-of-project text file, and
        insert the text into the currently open document.
        """

        lastPath = self.mainConf.lastPath

        extFilter = [
            "Text files (*.txt)",
            "Markdown files (*.md)",
            "All files (*.*)",
        ]
        dlgOpt  = QFileDialog.Options()
        dlgOpt |= QFileDialog.DontUseNativeDialog
        inPath  = QFileDialog.getOpenFileName(
            self,"Import File",lastPath,options=dlgOpt,filter=";;".join(extFilter)
        )
        if inPath:
            loadFile = inPath[0]
        else:
            return False

        if loadFile.strip() == "":
            return False

        theText = None
        try:
            with open(loadFile,mode="rt",encoding="utf8") as inFile:
                theText = inFile.read()
            self.mainConf.setLastPath(loadFile)
        except Exception as e:
            self.makeAlert(
                ["Could not read file. The file must be an existing text file.",str(e)],
                nwAlert.ERROR
            )
            return False

        if self.docEditor.theHandle is None:
            self.makeAlert(
                ["Please open a document to import the text file into."],
                nwAlert.ERROR
            )
            return False

        if not self.docEditor.isEmpty():
            if self.mainConf.showGUI:
                msgBox = QMessageBox()
                msgRes = msgBox.question(self, "Import Document",(
                    "Importing the file will overwrite the current content of the document. "
                    "Do you want to proceed?"
                ))
                if msgRes != QMessageBox.Yes:
                    return False
            else:
                return False

        self.docEditor.replaceText(theText)

        return True

    def mergeDocuments(self):
        """Merge multiple documents to one single new document.
        """
        if self.mainConf.showGUI:
            dlgMerge = GuiDocMerge(self, self.theProject)
            dlgMerge.exec_()
        return True

    def splitDocument(self):
        """Split a single document into multiple documents.
        """
        if self.mainConf.showGUI:
            dlgSplit = GuiDocSplit(self, self.theProject)
            dlgSplit.exec_()
        return True

    def passDocumentAction(self, theAction):
        """Pass on document action theAction to whatever document has
        the focus. If no document has focus, the action is discarded.
        """
        if self.docEditor.hasFocus():
            self.docEditor.docAction(theAction)
        elif self.docViewer.hasFocus():
            self.docViewer.docAction(theAction)
        else:
            logger.debug("Document action requested, but no document has focus")
        return True

    ##
    #  Tree Item Actions
    ##

    def openSelectedItem(self):
        tHandle = self.treeView.getSelectedHandle()
        if tHandle is None:
            logger.warning("No item selected")
            return False

        logger.verbose("Opening item %s" % tHandle)
        nwItem = self.theProject.projTree[tHandle]
        if nwItem.itemType == nwItemType.FILE:
            logger.verbose("Requested item %s is a file" % tHandle)
            self.openDocument(tHandle)
        else:
            logger.verbose("Requested item %s is not a file" % tHandle)

        return True

    def editItem(self):
        tHandle = self.treeView.getSelectedHandle()
        if tHandle is None:
            logger.warning("No item selected")
            return

        logger.verbose("Requesting change to item %s" % tHandle)
        if self.mainConf.showGUI:
            dlgProj = GuiItemEditor(self, self.theProject, tHandle)
            if dlgProj.exec_():
                self.treeView.setTreeItemValues(tHandle)
                self.treeMeta.updateViewBox(tHandle)
                self.docEditor.updateDocTitle(tHandle)
                self.docViewer.updateDocTitle(tHandle)

        return

    def rebuildTree(self):
        """Rebuild the project tree.
        """
        self._makeStatusIcons()
        self._makeImportIcons()
        self.treeView.clearTree()
        self.treeView.buildTree()
        return

    def rebuildIndex(self):
        """Rebuild the entire index.
        """

        if not self.hasProject:
            return False

        logger.debug("Rebuilding index ...")
        qApp.setOverrideCursor(QCursor(Qt.WaitCursor))
        tStart = time()

        self.treeView.saveTreeOrder()
        self.theIndex.clearIndex()
        nItems = len(self.theProject.projTree)

        theDoc = NWDoc(self.theProject, self)
        for nDone, tItem in enumerate(self.theProject.projTree):
            if tItem is not None and tItem.itemType == nwItemType.FILE:
                logger.verbose("Scanning: %s" % tItem.itemName)
                theText = theDoc.openDocument(tItem.itemHandle, showStatus=False)

                # Build tag index
                self.theIndex.scanText(tItem.itemHandle, theText)

                # Get Word Counts
                cC, wC, pC = self.theIndex.getCounts(tItem.itemHandle)
                tItem.setCharCount(cC)
                tItem.setWordCount(wC)
                tItem.setParaCount(pC)
                self.treeView.propagateCount(tItem.itemHandle, wC)
                self.treeView.projectWordCount()

            self.statusBar.setStatus("Building index: %.2f%%" % (100.0*(nDone + 1)/nItems))

        self.docEditor.reloadText()
        qApp.restoreOverrideCursor()
        tEnd = time()

        if self.mainConf.showGUI:
            self.makeAlert(
                "Project index rebuilt in %.3f seconds." % (tEnd - tStart), nwAlert.INFO
            )

        return True

    def rebuildOutline(self):
        """Force a rebuild of the Outline view.
        """
        logger.verbose("Forcing a rebuild of the Project Outline")
        self.tabWidget.setCurrentWidget(self.splitOutline)
        self.projView.refreshTree(overRide=True)
        return True

    ##
    #  Main Dialogs
    ##

    def openProjectDialog(self):
        dlgOpt  = QFileDialog.Options()
        dlgOpt |= QFileDialog.DontUseNativeDialog
        projFile, _ = QFileDialog.getOpenFileName(
            self, "Open novelWriter Project", "",
            "novelWriter Project File (%s);;All Files (*)" % nwFiles.PROJ_FILE,
            options=dlgOpt
        )
        if projFile:
            return projFile
        return None

    def saveProjectDialog(self):
        dlgOpt  = QFileDialog.Options()
        dlgOpt |= QFileDialog.ShowDirsOnly
        dlgOpt |= QFileDialog.DontUseNativeDialog
        projPath = QFileDialog.getExistingDirectory(
            self, "Save novelWriter Project", "", options=dlgOpt
        )
        if projPath:
            return projPath
        return None

    def newProjectDialog(self):
        dlgOpt  = QFileDialog.Options()
        dlgOpt |= QFileDialog.ShowDirsOnly
        dlgOpt |= QFileDialog.DontUseNativeDialog
        projPath = QFileDialog.getExistingDirectory(
            self, "Select Location for New novelWriter Project", "", options=dlgOpt
        )
        if projPath:
            return projPath
        return None

    def editConfigDialog(self):
        dlgConf = GuiConfigEditor(self, self.theProject)
        if dlgConf.exec_() == QDialog.Accepted:
            logger.debug("Applying new preferences")
            self.initMain()
            self.theTheme.updateTheme()
            self.saveDocument()
            self.docEditor.initEditor()
            self.docViewer.initViewer()
        return True

    def editProjectDialog(self):
        if self.hasProject:
            dlgProj = GuiProjectEditor(self, self.theProject)
            dlgProj.exec_()
            self._setWindowTitle(self.theProject.projName)
        return True

    def buildProjectDialog(self):
        if self.hasProject:
            dlgExport = GuiBuildNovel(self, self.theProject)
            dlgExport.exec_()
        return True

    def showSessionLogDialog(self):
        if self.hasProject:
            dlgTLine = GuiSessionLogView(self, self.theProject)
            dlgTLine.exec_()
        return True

    def makeAlert(self, theMessage, theLevel=nwAlert.INFO):
        """Alert both the user and the logger at the same time. Message
        can be either a string or an array of strings. Severity level is
        0 = info, 1 = warning, and 2 = error.
        """

        if isinstance(theMessage, list):
            popMsg = " ".join(theMessage)
            logMsg = theMessage
        else:
            popMsg = theMessage
            logMsg = [theMessage]

        msgBox = QMessageBox()
        if theLevel == nwAlert.INFO:
            for msgLine in logMsg:
                logger.info(msgLine)
            msgBox.information(self, "Information", popMsg)
        elif theLevel == nwAlert.WARN:
            for msgLine in logMsg:
                logger.warning(msgLine)
            msgBox.warning(self, "Warning", popMsg)
        elif theLevel == nwAlert.ERROR:
            for msgLine in logMsg:
                logger.error(msgLine)
            msgBox.critical(self, "Error", popMsg)
        elif theLevel == nwAlert.BUG:
            for msgLine in logMsg:
                logger.error(msgLine)
            popMsg += "<br>This is a bug!"
            msgBox.critical(self, "Internal Error", popMsg)

        return

    def reportConfErr(self):
        """Checks if the Config module has any errors to report, and let
        the user know if this is the case. The Config module caches
        errors since it is initialised before the GUI itself.
        """
        if self.mainConf.hasError:
            self.makeAlert(self.mainConf.getErrData(), nwAlert.ERROR)
            return True
        return False

    ##
    #  Main Window Actions
    ##

    def closeMain(self):

        if self.mainConf.showGUI and self.hasProject:
            msgBox = QMessageBox()
            msgRes = msgBox.question(
                self, "Exit", "Do you want to save changes and exit?"
            )
            if msgRes != QMessageBox.Yes:
                return False

        logger.info("Exiting %s" % nw.__package__)
        if self.hasProject:
            self.closeProject(True)

        self.mainConf.setTreeColWidths(self.treeView.getColumnSizes())
        if not self.mainConf.isFullScreen:
            self.mainConf.setWinSize(self.width(), self.height())
        if not self.isZenMode:
            self.mainConf.setMainPanePos(self.splitMain.sizes())
            self.mainConf.setDocPanePos(self.splitView.sizes())
        self.mainConf.saveConfig()
        self.reportConfErr()

        qApp.quit()

        return True

    def setFocus(self, paneNo):
        if paneNo == 1:
            self.treeView.setFocus()
        elif paneNo == 2:
            self.docEditor.setFocus()
        elif paneNo == 3:
            self.docViewer.setFocus()
        return

    def closeDocEditor(self):
        self.closeDocument()
        self.theProject.setLastEdited(None)
        return

    def closeDocViewer(self):
        self.docViewer.clearViewer()
        self.theProject.setLastViewed(None)
        bPos = self.splitMain.sizes()
        self.viewPane.setVisible(False)
        vPos = [bPos[1],0]
        self.splitView.setSizes(vPos)
        return not self.viewPane.isVisible()

    def toggleZenMode(self):
        """Main GUI Zen Mode hides tree, view pane and optionally also
        statusbar and menu.
        """

        if self.docEditor.theHandle is None:
            logger.error("No document open, so not activating Zen Mode")
            return False

        self.isZenMode = not self.isZenMode
        if self.isZenMode:
            logger.debug("Activating Zen mode")
            self.tabWidget.setCurrentWidget(self.splitView)
        else:
            logger.debug("Deactivating Zen mode")

        isVisible = not self.isZenMode
        self.treePane.setVisible(isVisible)
        self.statusBar.setVisible(isVisible)
        self.mainMenu.setVisible(isVisible)
        self.tabWidget.tabBar().setVisible(isVisible)

        if self.viewPane.isVisible():
            self.viewPane.setVisible(False)
        elif self.docViewer.theHandle is not None:
            self.viewPane.setVisible(True)

        return True

    def toggleFullScreenMode(self):
        """Main GUI full screen mode. The mode is tracked by the flag
        in config. This only tracks whether the window has been
        maximised using the internal commands, and may not be correct
        if the user uses the system window manager. Currently, Qt
        doesn't have access to the exact state of the window.
        """

        self.setWindowState(self.windowState() ^ Qt.WindowFullScreen)

        winState = self.windowState() & Qt.WindowFullScreen == Qt.WindowFullScreen
        if winState:
            logger.debug("Activated full screen mode")
        else:
            logger.debug("Deactivated full screen mode")

        self.mainConf.isFullScreen = winState

        return

    ##
    #  Internal Functions
    ##

    def _connectMenuActions(self):
        """Connect to the main window all menu actions that need to be
        available also when the main menu is hidden.
        """
        self.addAction(self.mainMenu.aSaveProject)
        self.addAction(self.mainMenu.aExitNW)
        self.addAction(self.mainMenu.aSaveDoc)
        self.addAction(self.mainMenu.aFileDetails)
        self.addAction(self.mainMenu.aZenMode)
        self.addAction(self.mainMenu.aFullScreen)
        self.addAction(self.mainMenu.aEditUndo)
        self.addAction(self.mainMenu.aEditRedo)
        self.addAction(self.mainMenu.aEditCut)
        self.addAction(self.mainMenu.aEditCopy)
        self.addAction(self.mainMenu.aEditPaste)
        self.addAction(self.mainMenu.aSelectAll)
        self.addAction(self.mainMenu.aSelectPar)
        self.addAction(self.mainMenu.aFmtBold)
        self.addAction(self.mainMenu.aFmtItalic)
        self.addAction(self.mainMenu.aFmtULine)
        self.addAction(self.mainMenu.aFmtDQuote)
        self.addAction(self.mainMenu.aFmtSQuote)
        self.addAction(self.mainMenu.aFmtHead1)
        self.addAction(self.mainMenu.aFmtHead2)
        self.addAction(self.mainMenu.aFmtHead3)
        self.addAction(self.mainMenu.aFmtHead4)
        self.addAction(self.mainMenu.aFmtComment)
        self.addAction(self.mainMenu.aFmtNoFormat)
        self.addAction(self.mainMenu.aSpellCheck)
        self.addAction(self.mainMenu.aReRunSpell)
        self.addAction(self.mainMenu.aPreferences)
        self.addAction(self.mainMenu.aHelp)
        return True

    def _setWindowTitle(self, projName=None):
        winTitle = "%s" % nw.__package__
        if projName is not None:
            winTitle += " - %s" % projName
        self.setWindowTitle(winTitle)
        return True

    def _autoSaveProject(self):
        if (self.hasProject and self.theProject.projChanged and
            self.theProject.projPath is not None):
            logger.debug("Autosaving project")
            self.saveProject(autoSave=True)
        return

    def _autoSaveDocument(self):
        if self.hasProject and self.docEditor.docChanged:
            logger.debug("Autosaving document")
            self.saveDocument()
        return

    def _makeStatusIcons(self):
        self.statusIcons = {}
        for sLabel, sCol, _ in self.theProject.statusItems:
            theIcon = QPixmap(32,32)
            theIcon.fill(QColor(*sCol))
            self.statusIcons[sLabel] = QIcon(theIcon)
        return

    def _makeImportIcons(self):
        self.importIcons = {}
        for sLabel, sCol, _ in self.theProject.importItems:
            theIcon = QPixmap(32,32)
            theIcon.fill(QColor(*sCol))
            self.importIcons[sLabel] = QIcon(theIcon)
        return

    ##
    #  Events
    ##

    def closeEvent(self, theEvent):
        if self.closeMain():
            theEvent.accept()
        else:
            theEvent.ignore()
        return

    ##
    #  Signal Handlers
    ##

    def _treeSingleClick(self):
        sHandle = self.treeView.getSelectedHandle()
        if sHandle is not None:
            self.treeMeta.updateViewBox(sHandle)
        return

    def _treeDoubleClick(self, tItem, colNo):
        tHandle = tItem.text(3)
        logger.verbose("User double clicked tree item with handle %s" % tHandle)
        nwItem = self.theProject.projTree[tHandle]
        if nwItem.itemType == nwItemType.FILE:
            logger.verbose("Requested item %s is a file" % tHandle)
            self.openDocument(tHandle)
        else:
            logger.verbose("Requested item %s is a folder" % tHandle)
        return

    def _treeKeyPressReturn(self):
        tHandle = self.treeView.getSelectedHandle()
        logger.verbose("User pressed return on tree item with handle %s" % tHandle)
        nwItem = self.theProject.projTree[tHandle]
        if nwItem.itemType == nwItemType.FILE:
            logger.verbose("Requested item %s is a file" % tHandle)
            self.openDocument(tHandle)
        else:
            logger.verbose("Requested item %s is a folder" % tHandle)
        return

    def _keyPressEscape(self):
        """When the escape key is pressed somewhere in the main window,
        do the following, in order:
        """
        if self.searchBar.isVisible():
            self.searchBar.setVisible(False)
            return
        elif self.isZenMode:
            self.toggleZenMode()
        return

    def _mainTabChanged(self, tabIndex):
        """Activated when the main window tab is changed.
        """
        if tabIndex == self.idxTabEdit:
            logger.verbose("Editor tab activated")
        elif tabIndex == self.idxTabProj:
            logger.verbose("Project outline tab activated")
            if self.hasProject:
                self.projView.refreshTree()
        return

# END Class GuiMain
