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

# Copyright (c) 2004 - 2020 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog for entering character classes.
"""


from PyQt5.QtCore import QRegExp
from PyQt5.QtGui import QRegExpValidator
from PyQt5.QtWidgets import (
    QSizePolicy, QSpacerItem, QWidget, QHBoxLayout, QLineEdit, QPushButton,
    QDialog, QScrollArea, QComboBox, QVBoxLayout, QLabel
)

from .Ui_PyRegExpWizardCharactersDialog import (
    Ui_PyRegExpWizardCharactersDialog
)


class PyRegExpWizardCharactersDialog(
        QDialog, Ui_PyRegExpWizardCharactersDialog):
    """
    Class implementing a dialog for entering character classes.
    """
    specialChars = {
        4: "\\a",
        5: "\\f",
        6: "\\n",
        7: "\\r",
        8: "\\t",
        9: "\\v"
    }
    
    predefinedClasses = ["\\s", "\\S", "\\w", "\\W", "\\d", "\\D"]
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent parent widget (QWidget)
        """
        super(PyRegExpWizardCharactersDialog, self).__init__(parent)
        self.setupUi(self)
        
        self.comboItems = []
        self.singleComboItems = []      # these are in addition to the above
        self.comboItems.append(self.tr("Normal character"))
        self.comboItems.append(
            self.tr("Unicode character in hexadecimal notation"))
        self.comboItems.append(
            self.tr("Unicode character in octal notation"))
        self.singleComboItems.append(self.tr("---"))
        self.singleComboItems.append(self.tr("Bell character (\\a)"))
        self.singleComboItems.append(self.tr("Page break (\\f)"))
        self.singleComboItems.append(self.tr("Line feed (\\n)"))
        self.singleComboItems.append(self.tr("Carriage return (\\r)"))
        self.singleComboItems.append(self.tr("Horizontal tabulator (\\t)"))
        self.singleComboItems.append(self.tr("Vertical tabulator (\\v)"))
        
        self.charValidator = QRegExpValidator(QRegExp(".{0,1}"), self)
        self.hexValidator = QRegExpValidator(QRegExp("[0-9a-fA-F]{0,4}"), self)
        self.octValidator = QRegExpValidator(QRegExp("[0-3]?[0-7]{0,2}"), self)
        
        # generate dialog part for single characters
        self.singlesBoxLayout = QVBoxLayout(self.singlesBox)
        self.singlesBoxLayout.setObjectName("singlesBoxLayout")
        self.singlesBoxLayout.setSpacing(6)
        self.singlesBoxLayout.setContentsMargins(6, 6, 6, 6)
        self.singlesBox.setLayout(self.singlesBoxLayout)
        self.singlesView = QScrollArea(self.singlesBox)
        self.singlesView.setObjectName("singlesView")
        self.singlesBoxLayout.addWidget(self.singlesView)
        
        self.singlesItemsBox = QWidget(self)
        self.singlesView.setWidget(self.singlesItemsBox)
        self.singlesItemsBox.setObjectName("singlesItemsBox")
        self.singlesItemsBoxLayout = QVBoxLayout(self.singlesItemsBox)
        self.singlesItemsBoxLayout.setContentsMargins(6, 6, 6, 6)
        self.singlesItemsBoxLayout.setSpacing(6)
        self.singlesItemsBox.setLayout(self.singlesItemsBoxLayout)
        self.singlesEntries = []
        self.__addSinglesLine()
        
        hlayout0 = QHBoxLayout()
        hlayout0.setContentsMargins(0, 0, 0, 0)
        hlayout0.setSpacing(6)
        hlayout0.setObjectName("hlayout0")
        self.moreSinglesButton = QPushButton(
            self.tr("Additional Entries"), self.singlesBox)
        self.moreSinglesButton.setObjectName("moreSinglesButton")
        hlayout0.addWidget(self.moreSinglesButton)
        hspacer0 = QSpacerItem(
            30, 20, QSizePolicy.Expanding, QSizePolicy.Minimum)
        hlayout0.addItem(hspacer0)
        self.singlesBoxLayout.addLayout(hlayout0)
        self.moreSinglesButton.clicked.connect(self.__addSinglesLine)
        
        # generate dialog part for character ranges
        self.rangesBoxLayout = QVBoxLayout(self.rangesBox)
        self.rangesBoxLayout.setObjectName("rangesBoxLayout")
        self.rangesBoxLayout.setSpacing(6)
        self.rangesBoxLayout.setContentsMargins(6, 6, 6, 6)
        self.rangesBox.setLayout(self.rangesBoxLayout)
        self.rangesView = QScrollArea(self.rangesBox)
        self.rangesView.setObjectName("rangesView")
        self.rangesBoxLayout.addWidget(self.rangesView)
        
        self.rangesItemsBox = QWidget(self)
        self.rangesView.setWidget(self.rangesItemsBox)
        self.rangesItemsBox.setObjectName("rangesItemsBox")
        self.rangesItemsBoxLayout = QVBoxLayout(self.rangesItemsBox)
        self.rangesItemsBoxLayout.setContentsMargins(6, 6, 6, 6)
        self.rangesItemsBoxLayout.setSpacing(6)
        self.rangesItemsBox.setLayout(self.rangesItemsBoxLayout)
        self.rangesEntries = []
        self.__addRangesLine()
        
        hlayout1 = QHBoxLayout()
        hlayout1.setContentsMargins(0, 0, 0, 0)
        hlayout1.setSpacing(6)
        hlayout1.setObjectName("hlayout1")
        self.moreRangesButton = QPushButton(
            self.tr("Additional Entries"), self.rangesBox)
        self.moreSinglesButton.setObjectName("moreRangesButton")
        hlayout1.addWidget(self.moreRangesButton)
        hspacer1 = QSpacerItem(
            30, 20, QSizePolicy.Expanding, QSizePolicy.Minimum)
        hlayout1.addItem(hspacer1)
        self.rangesBoxLayout.addLayout(hlayout1)
        self.moreRangesButton.clicked.connect(self.__addRangesLine)
        
    def __addSinglesLine(self):
        """
        Private slot to add a line of entry widgets for single characters.
        """
        hbox = QWidget(self.singlesItemsBox)
        hboxLayout = QHBoxLayout(hbox)
        hboxLayout.setContentsMargins(0, 0, 0, 0)
        hboxLayout.setSpacing(6)
        hbox.setLayout(hboxLayout)
        cb1 = QComboBox(hbox)
        cb1.setEditable(False)
        cb1.addItems(self.comboItems)
        cb1.addItems(self.singleComboItems)
        hboxLayout.addWidget(cb1)
        le1 = QLineEdit(hbox)
        le1.setValidator(self.charValidator)
        hboxLayout.addWidget(le1)
        cb2 = QComboBox(hbox)
        cb2.setEditable(False)
        cb2.addItems(self.comboItems)
        cb2.addItems(self.singleComboItems)
        hboxLayout.addWidget(cb2)
        le2 = QLineEdit(hbox)
        le2.setValidator(self.charValidator)
        hboxLayout.addWidget(le2)
        self.singlesItemsBoxLayout.addWidget(hbox)
        
        cb1.activated[int].connect(
            lambda i: self.__singlesCharTypeSelected(i, cb1))
        cb2.activated[int].connect(
            lambda i: self.__singlesCharTypeSelected(i, cb2))
        hbox.show()
        
        self.singlesItemsBox.adjustSize()
        
        self.singlesEntries.append([cb1, le1])
        self.singlesEntries.append([cb2, le2])
        
    def __addRangesLine(self):
        """
        Private slot to add a line of entry widgets for character ranges.
        """
        hbox = QWidget(self.rangesItemsBox)
        hboxLayout = QHBoxLayout(hbox)
        hboxLayout.setContentsMargins(0, 0, 0, 0)
        hboxLayout.setSpacing(6)
        hbox.setLayout(hboxLayout)
        cb1 = QComboBox(hbox)
        cb1.setEditable(False)
        cb1.addItems(self.comboItems)
        hboxLayout.addWidget(cb1)
        l1 = QLabel(self.tr("Between:"), hbox)
        hboxLayout.addWidget(l1)
        le1 = QLineEdit(hbox)
        le1.setValidator(self.charValidator)
        hboxLayout.addWidget(le1)
        l2 = QLabel(self.tr("And:"), hbox)
        hboxLayout.addWidget(l2)
        le2 = QLineEdit(hbox)
        le2.setValidator(self.charValidator)
        hboxLayout.addWidget(le2)
        self.rangesItemsBoxLayout.addWidget(hbox)
        
        cb1.activated[int].connect(
            lambda i: self.__rangesCharTypeSelected(i, cb1))
        
        hbox.show()
        
        self.rangesItemsBox.adjustSize()
        
        self.rangesEntries.append([cb1, le1, le2])
        
    def __performSelectedAction(self, index, lineedit):
        """
        Private method performing some actions depending on the input.
        
        @param index selected list index (integer)
        @param lineedit line edit widget to act on (QLineEdit)
        """
        if index < 3:
            lineedit.setEnabled(True)
            if index == 0:
                lineedit.setValidator(self.charValidator)
            elif index == 1:
                lineedit.setValidator(self.hexValidator)
            elif index == 2:
                lineedit.setValidator(self.octValidator)
        elif index > 3:
            lineedit.setEnabled(False)
        lineedit.clear()
        
    def __singlesCharTypeSelected(self, index, combo):
        """
        Private slot to handle the activated(int) signal of the single chars
        combo boxes.
        
        @param index selected list index
        @type int
        @param combo reference to the combo box
        @type QComboBox
        """
        for entriesList in self.singlesEntries:
            if combo == entriesList[0]:
                self.__performSelectedAction(index, entriesList[1])
                break
        
    def __rangesCharTypeSelected(self, index, combo):
        """
        Private slot to handle the activated(int) signal of the char ranges
        combo boxes.
        
        @param index selected list index
        @type int
        @param combo reference to the combo box
        @type QComboBox
        """
        for entriesList in self.rangesEntries:
            if combo == entriesList[0]:
                self.__performSelectedAction(index, entriesList[1])
                self.__performSelectedAction(index, entriesList[2])
                break
        
    def __formatCharacter(self, index, char):
        """
        Private method to format the characters entered into the dialog.
        
        @param index selected list index (integer)
        @param char character string enetered into the dialog (string)
        @return formated character string (string)
        """
        if index == 0:
            return char
        elif index == 1:
            return "\\x{0}".format(char.lower())
        elif index == 2:
            return "\\0{0}".format(char)
        else:
            try:
                return self.specialChars[index]
            except KeyError:
                return ""
        
    def getCharacters(self):
        """
        Public method to return the character string assembled via the dialog.
        
        @return formatted string for character classes (string)
        """
        regexp = ""
        
        # negative character range
        if self.negativeCheckBox.isChecked():
            regexp += "^"
            
        # predefined character ranges
        if self.wordCharCheckBox.isChecked():
            regexp += "\\w"
        if self.nonWordCharCheckBox.isChecked():
            regexp += "\\W"
        if self.digitsCheckBox.isChecked():
            regexp += "\\d"
        if self.nonDigitsCheckBox.isChecked():
            regexp += "\\D"
        if self.whitespaceCheckBox.isChecked():
            regexp += "\\s"
        if self.nonWhitespaceCheckBox.isChecked():
            regexp += "\\S"
            
        # single characters
        for entrieslist in self.singlesEntries:
            index = entrieslist[0].currentIndex()
            char = entrieslist[1].text()
            regexp += self.__formatCharacter(index, char)
        
        # character ranges
        for entrieslist in self.rangesEntries:
            if (
                entrieslist[1].text() == "" or
                entrieslist[2].text() == ""
            ):
                continue
            index = entrieslist[0].currentIndex()
            char1 = entrieslist[1].text()
            char2 = entrieslist[2].text()
            regexp += "{0}-{1}".format(
                self.__formatCharacter(index, char1),
                self.__formatCharacter(index, char2))
        
        if regexp:
            if (
                (len(regexp) == 2 and
                 (regexp in self.predefinedClasses or
                  regexp in self.specialChars)) or
                len(regexp) == 1
            ):
                return regexp
            else:
                return "[{0}]".format(regexp)
        else:
            return ""
