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

# Copyright (c) 2016 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to select QtHelp documentation sets to be
installed.
"""


import os
import shutil

from PyQt5.QtCore import pyqtSlot, Qt
from PyQt5.QtWidgets import QDialog, QDialogButtonBox, QTreeWidgetItem

from E5Gui import E5MessageBox

from .Ui_QtHelpDocumentationSelectionDialog import (
    Ui_QtHelpDocumentationSelectionDialog
)


class QtHelpDocumentationSelectionDialog(
        QDialog, Ui_QtHelpDocumentationSelectionDialog):
    """
    Class implementing a dialog to select QtHelp documentation sets to be
    installed.
    """
    AddMode = "Add"
    ManageMode = "Manage"
    
    def __init__(self, helpDocuments, mode, parent=None):
        """
        Constructor
        
        @param helpDocuments dictionary containing the lists of help documents
            to be shown
        @type dict of lists of str
        @param mode mode of the dialog
        @type str
        @param parent reference to the parent widget
        @type QWidget
        """
        super(QtHelpDocumentationSelectionDialog, self).__init__(parent)
        self.setupUi(self)
        
        if mode == QtHelpDocumentationSelectionDialog.AddMode:
            self.buttonBox.button(QDialogButtonBox.Close).hide()
        else:
            self.buttonBox.button(QDialogButtonBox.Ok).hide()
            self.buttonBox.button(QDialogButtonBox.Cancel).hide()
        
        for category in helpDocuments:
            parentItem = QTreeWidgetItem(self.documentationList, [category])
            for document in helpDocuments[category]:
                item = QTreeWidgetItem(parentItem,
                                       [os.path.basename(document)])
                item.setData(0, Qt.UserRole, document)
                parentItem.setData(0, Qt.UserRole, os.path.dirname(document))
        self.documentationList.sortItems(0, Qt.AscendingOrder)
        
        self.on_documentationList_itemSelectionChanged()
    
    @pyqtSlot()
    def on_documentationList_itemSelectionChanged(self):
        """
        Private slot handling the selection of items.
        """
        selectedCategoriesCount = 0
        selectedDocumentSetCount = 0
        for itm in self.documentationList.selectedItems():
            if itm.parent() is None:
                selectedCategoriesCount += 1
            else:
                selectedDocumentSetCount += 1
        
        self.deleteButton.setEnabled(selectedDocumentSetCount > 0)
        self.deleteCategoryButton.setEnabled(selectedCategoriesCount > 0)
    
    @pyqtSlot()
    def on_deleteButton_clicked(self):
        """
        Private slot to delete the selected documentation sets.
        """
        yes = E5MessageBox.yesNo(
            self,
            self.tr("Delete Documentation Sets"),
            self.tr("""Shall the selected documentation sets really be"""
                    """ deleted?"""))
        if yes:
            for itm in self.documentationList.selectedItems():
                if itm.parent is None:
                    # it is a category item, skip it
                    continue
                
                category = itm.parent()
                fileName = itm.data(0, Qt.UserRole)
                try:
                    os.remove(fileName)
                except OSError as err:
                    E5MessageBox.warning(
                        self,
                        self.tr("Delete Documentation Sets"),
                        self.tr("""<p>The documentation set <b>{0}</b> could"""
                                """ not be deleted.</p><p>Reason: {1}</p>""")
                        .format(fileName, str(err)))
                    continue
                
                category.removeChild(itm)
                del itm
                
                if category.childCount() == 0:
                    self.__deleteCategory(category)
    
    @pyqtSlot()
    def on_deleteCategoryButton_clicked(self):
        """
        Private slot to delete the selected documentation set categories.
        """
        yes = E5MessageBox.yesNo(
            self,
            self.tr("Delete Documentation Sets"),
            self.tr("""Shall the selected documentation set categories"""
                    """ really be deleted?"""))
        if yes:
            categories = []
            for itm in self.documentationList.selectedItems():
                if itm.parent() is None:
                    categories.append(itm)
            for category in categories:
                self.__deleteCategory(category)
    
    @pyqtSlot()
    def on_deleteAllButton_clicked(self):
        """
        Private slot to delete all documentation sets.
        """
        yes = E5MessageBox.yesNo(
            self,
            self.tr("Delete Documentation Sets"),
            self.tr("""Shall all documentation sets really be deleted?"""))
        if yes:
            categories = []
            for index in range(self.documentationList.topLevelItemCount()):
                categories.append(
                    self.documentationList.topLevelItem(index))
            for category in categories:
                self.__deleteCategory(category)
    
    def __deleteCategory(self, category):
        """
        Private method to delete a category.
        
        @param category reference to the category item
        @type QTreeWidgetItem
        """
        categoryDir = category.data(0, Qt.UserRole)
        shutil.rmtree(categoryDir, True)
        
        self.documentationList.takeTopLevelItem(
            self.documentationList.indexOfTopLevelItem(category))
        del category
    
    def getData(self):
        """
        Public method to retrieve the selected help documents.
        
        @return list of QtHelp documentation sets to be installed
        @rtype list of str
        """
        documents = []
        for item in self.documentationList.selectedItems():
            fileName = item.data(0, Qt.UserRole)
            if fileName:
                documents.append(fileName)
        return documents
