#!/usr/bin/env python
# -*- coding: UTF-8 -*-

""" Module mainWindow: This module contains classes for creating a standard PySide Qt QMainWindow instance. """
import traceback

from PySide.QtGui import QDialog, QMainWindow
import logging


class _GCProtector(object):
    """
    This class acts as a holder for a static class var in order to
    prevent Qt _widgets from being garbage-collected
    """

    # declare static class var
    widgets = []


class MainWindow(QMainWindow):
    """
    This class creates a new QMainWindow and setups widgets onto it.
    """

    logger = logging.getLogger( __name__ )


    def __init__( self, qmainwindow, parent=None, *args, **kwargs ):
        """
        The constructor. Creates an instance of QMainWindow and handles order of
        data population along with connecting signals/slots.

        :param parent:
        :return:
        """

        # call base class constructor
        super( MainWindow, self ).__init__( *args, **kwargs )

        # setup UI widgets to the QMainWindow
        qmainwindow.setupUi(self)

        # add to garbage collection protection
        _GCProtector.widgets.append(self)

        # create reference to the qmainwindow widget
        self.ui = qmainwindow
        try: self.populateData()
        except Exception:
            self.logger.error('### Could not populate data to widget!!! \n {0}'
                         .format(traceback.print_exc()))
            raise Exception

        self.logger.debug('Data successfully populated to widget!')

        try: self.makeConnections()
        except Exception:
            self.logger.error('### Could not make connections to signals/slots!!! \n {0}'
                         .format(traceback.print_exc()))
            raise Exception

        self.logger.debug('Connections successfully made for widget!')

        self.show()


    def makeConnections(self, *args, **kwargs):
        """
        This method handles making connections from the
        Qt widgets to corresponding signals/slots.

        :return:
        """
        pass


    def populateData(self, *args, **kwargs ):
        """
        This method populates the widget with data.

        :return:
        """
        pass


    def closeEvent(self, *args, **kwargs):
        """
        This overrides the base event in ``QDialog``.

        :param args:
        :param kwargs:
        :return:
        """

        # Remove widget objects from GC protection
        if self in _GCProtector.widgets:
            _GCProtector.widgets.remove(self)


    def cancelAction(self):
        """
        This method is run when the user chooses to close the widget via the UI.

        :return:
        """

        self.close()


class MainDialog(QDialog):
    """
    This class creates a new QDialog and setups widgets onto it.
    """

    logger = logging.getLogger( __name__ )

    def __init__( self, qform, parent=None, title=None,
                  flags=None, modal=False, *args, **kwargs ):
        """
        The constructor.

        :param qform:
        :param parent: ``QObject`` instance that will act as the parent widget for this dialog.
        :param title: ``str`` indicating the title that the dialog should have.
        :param flags:
        :param modal: ``bool`` determining if the dialog being created should be modal
                    application-wide. (i.e. Other widgets have interaction disabled)
        :param args:
        :param kwargs:
        :return:
        """

        # call base class constructor
        super( MainDialog, self ).__init__( *args, **kwargs )

        # create reference to the qmainwindow widget
        self.ui = qform
        self._instance = None

        # setup widgets to the QDialog
        qform.setupUi(self)

        # add to garbage collection protection
        _GCProtector.widgets.append(self)

        if title:
            self.setWindowTitle(title)
        if flags:
            self.setWindowFlags(flags)
        if modal:
            self.setModal(True)

        self.populateData()

        self.logger.debug('Data successfully populated to widget!')

        self.makeConnections()

        self.logger.debug('Connections successfully made for widget!')

        self.show()


    def makeConnections(self, *args, **kwargs):
        """
        This method handles making connections from the
        Qt widgets to corresponding signals/slots.

        :return:
        """
        pass


    def populateData(self, *args, **kwargs ):
        """
        This method populates the widget with data.

        :return:
        """
        pass


    def closeEvent(self, *args, **kwargs):
        """
        This overrides the base event in ``QDialog``.

        :param args:
        :param kwargs:
        :return:
        """

        # Remove widget objects from GC protection
        if self in _GCProtector.widgets:
            _GCProtector.widgets.remove(self)


    def cancelAction(self):
        """
        This method is run when the user chooses to close the widget via the UI.

        :return:
        """

        self.close()