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

# Copyright (c) 2010 - 2014 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing QMessageBox replacements and more convenience function.
"""

from __future__ import unicode_literals

from PyQt4.QtCore import Qt
from PyQt4.QtGui import QMessageBox, QApplication

###############################################################################
##  Mappings to standard QMessageBox                                         ##
###############################################################################

# QMessageBox.Icon
NoIcon = QMessageBox.NoIcon
Critical = QMessageBox.Critical
Information = QMessageBox.Information
Question = QMessageBox.Question
Warning = QMessageBox.Warning

StandardButtons = QMessageBox.StandardButtons

# QMessageBox.StandardButton
Abort = QMessageBox.Abort
Apply = QMessageBox.Apply
Cancel = QMessageBox.Cancel
Close = QMessageBox.Close
Discard = QMessageBox.Discard
Help = QMessageBox.Help
Ignore = QMessageBox.Ignore
No = QMessageBox.No
NoToAll = QMessageBox.NoToAll
Ok = QMessageBox.Ok
Open = QMessageBox.Open
Reset = QMessageBox.Reset
RestoreDefaults = QMessageBox.RestoreDefaults
Retry = QMessageBox.Retry
Save = QMessageBox.Save
SaveAll = QMessageBox.SaveAll
Yes = QMessageBox.Yes
YesToAll = QMessageBox.YesToAll
NoButton = QMessageBox.NoButton

# QMessageBox.ButtonRole
AcceptRole = QMessageBox.AcceptRole
ActionRole = QMessageBox.ActionRole
ApplyRole = QMessageBox.ApplyRole
DestructiveRole = QMessageBox.DestructiveRole
InvalidRole = QMessageBox.InvalidRole
HelpRole = QMessageBox.HelpRole
NoRole = QMessageBox.NoRole
RejectRole = QMessageBox.RejectRole
ResetRole = QMessageBox.ResetRole
YesRole = QMessageBox.YesRole

###############################################################################
##  Replacement for the QMessageBox class                                    ##
###############################################################################


class E5MessageBox(QMessageBox):
    """
    Class implementing a replacement for QMessageBox.
    """
    def __init__(self, icon, title, text, modal=False,
                 buttons=QMessageBox.StandardButtons(QMessageBox.NoButton),
                 parent=None):
        """
        Constructor
        
        @param icon type of icon to be shown (QMessageBox.Icon)
        @param title caption of the message box (string)
        @param text text to be shown by the message box (string)
        @keyparam modal flag indicating a modal dialog (boolean)
        @keyparam buttons set of standard buttons to generate (StandardButtons)
        @keyparam parent parent widget of the message box (QWidget)
        """
        super(E5MessageBox, self).__init__(parent)
        self.setIcon(icon)
        if modal:
            if parent is not None:
                self.setWindowModality(Qt.WindowModal)
            else:
                self.setWindowModality(Qt.ApplicationModal)
        else:
            self.setWindowModality(Qt.NonModal)
        if title == "":
            self.setWindowTitle("{0}".format(
                QApplication.applicationName()))
        else:
            self.setWindowTitle("{0} - {1}".format(
                QApplication.applicationName(), title))
        self.setText(text)
        self.setStandardButtons(buttons)

###############################################################################
##  Replacements for QMessageBox static methods                              ##
###############################################################################


def __messageBox(parent, title, text, icon,
                 buttons=QMessageBox.Ok, defaultButton=QMessageBox.NoButton,
                 textFormat=Qt.AutoText):
    """
    Private module function to show a modal message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param icon type of icon to be shown (QMessageBox.Icon)
    @param buttons flags indicating which buttons to show
        (QMessageBox.StandardButtons)
    @param defaultButton flag indicating the default button
        (QMessageBox.StandardButton)
    @param textFormat format of the text (Qt.TextFormat)
    @return button pressed by the user (QMessageBox.StandardButton)
    """
    messageBox = QMessageBox(parent)
    messageBox.setIcon(icon)
    if parent is not None:
        messageBox.setWindowModality(Qt.WindowModal)
    if title == "":
        messageBox.setWindowTitle("{0}".format(
            QApplication.applicationName()))
    else:
        messageBox.setWindowTitle("{0} - {1}".format(
            QApplication.applicationName(), title))
    messageBox.setTextFormat(textFormat)
    messageBox.setText(text)
    messageBox.setStandardButtons(buttons)
    messageBox.setDefaultButton(defaultButton)
    messageBox.exec_()
    clickedButton = messageBox.clickedButton()
    if clickedButton is None:
        return QMessageBox.NoButton
    else:
        return messageBox.standardButton(clickedButton)

# the about functions are here for consistancy
about = QMessageBox.about
aboutQt = QMessageBox.aboutQt


def critical(parent, title, text,
             buttons=QMessageBox.Ok, defaultButton=QMessageBox.NoButton):
    """
    Function to show a modal critical message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param buttons flags indicating which buttons to show
        (QMessageBox.StandardButtons)
    @param defaultButton flag indicating the default button
        (QMessageBox.StandardButton)
    @return button pressed by the user (QMessageBox.StandardButton)
    """
    return __messageBox(parent, title, text, QMessageBox.Critical,
                        buttons, defaultButton)


def information(parent, title, text,
                buttons=QMessageBox.Ok, defaultButton=QMessageBox.NoButton):
    """
    Function to show a modal information message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param buttons flags indicating which buttons to show
        (QMessageBox.StandardButtons)
    @param defaultButton flag indicating the default button
        (QMessageBox.StandardButton)
    @return button pressed by the user (QMessageBox.StandardButton)
    """
    return __messageBox(parent, title, text, QMessageBox.Information,
                        buttons, defaultButton)


def question(parent, title, text,
             buttons=QMessageBox.Ok, defaultButton=QMessageBox.NoButton):
    """
    Function to show a modal question message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param buttons flags indicating which buttons to show
        (QMessageBox.StandardButtons)
    @param defaultButton flag indicating the default button
        (QMessageBox.StandardButton)
    @return button pressed by the user (QMessageBox.StandardButton)
    """
    return __messageBox(parent, title, text, QMessageBox.Question,
                        buttons, defaultButton)


def warning(parent, title, text,
            buttons=QMessageBox.Ok, defaultButton=QMessageBox.NoButton):
    """
    Function to show a modal warning message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param buttons flags indicating which buttons to show
        (QMessageBox.StandardButtons)
    @param defaultButton flag indicating the default button
        (QMessageBox.StandardButton)
    @return button pressed by the user (QMessageBox.StandardButton)
    """
    return __messageBox(parent, title, text, QMessageBox.Warning,
                        buttons, defaultButton)

###############################################################################
##  Additional convenience functions                                         ##
###############################################################################


def yesNo(parent, title, text, icon=Question, yesDefault=False,
          textFormat=Qt.AutoText):
    """
    Function to show a model yes/no message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @keyparam icon icon for the dialog (Critical, Information, Question or
        Warning)
    @keyparam yesDefault flag indicating that the Yes button should be the
        default button (boolean)
    @param textFormat format of the text (Qt.TextFormat)
    @return flag indicating the selection of the Yes button (boolean)
    """
    assert icon in [Critical, Information, Question, Warning]
    
    res = __messageBox(
        parent, title, text, icon,
        QMessageBox.StandardButtons(QMessageBox.Yes | QMessageBox.No),
        yesDefault and QMessageBox.Yes or QMessageBox.No,
        textFormat)
    return res == QMessageBox.Yes


def retryAbort(parent, title, text, icon=Question, textFormat=Qt.AutoText):
    """
    Function to show a model abort/retry message box.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @keyparam icon icon for the dialog (Critical, Information, Question or
        Warning)
    @param textFormat format of the text (Qt.TextFormat)
    @return flag indicating the selection of the Retry button (boolean)
    """
    assert icon in [Critical, Information, Question, Warning]
    
    res = __messageBox(
        parent, title, text, icon,
        QMessageBox.StandardButtons(QMessageBox.Retry | QMessageBox.Abort),
        QMessageBox.Retry,
        textFormat)
    return res == QMessageBox.Retry


def okToClearData(parent, title, text, saveFunc, textFormat=Qt.AutoText):
    """
    Function to show a model message box to ask for clearing the data.
    
    @param parent parent widget of the message box (QWidget)
    @param title caption of the message box (string)
    @param text text to be shown by the message box (string)
    @param saveFunc reference to a function performing the save action. It
        must be a parameterless function returning a flag indicating success.
    @param textFormat format of the text (Qt.TextFormat)
    @return flag indicating that it is ok to clear the data (boolean)
    """
    res = __messageBox(
        parent, title, text, QMessageBox.Warning,
        QMessageBox.StandardButtons(
            QMessageBox.Abort | QMessageBox.Discard | QMessageBox.Save),
        QMessageBox.Save,
        textFormat)
    if res == QMessageBox.Abort:
        return False
    if res == QMessageBox.Save:
        return saveFunc()
    return True
