"""
Opens up a 2nd window for docking mobu and R* widgets to
"""
import sys

from PySide import QtGui, QtCore

from RS.Tools import UI
from RS.Tools.UI import Application, QPrint


class SecondDockableWindow(UI.QtMainWindowBase):
    """
    Singleton class

    Do not instance more than one of this class!!

    This is the window for the second dockable window for motion builder
    """
    def __init__(self, parent=None):
        """
        Constructor
        """
        super(SecondDockableWindow, self).__init__(parent=parent, title='Secondary Dockable Window')
        self._mobuWindow = Application.GetMainWindow()

        self._mouseReleaseEventCalls = [
                        (QtCore.QEvent.Type.Move, QtCore.QEvent.Type.NonClientAreaMouseMove),
                        (QtCore.QEvent.Type.Move, QtCore.QEvent.Type.MouseButtonRelease)
                        ]
        self._lastEvent = None
        self._dockWidge = []
        self._dockWidgetLastEventDict = {}
        self.updateDockWidgets()

    def updateDockWidgets(self):
        """
        Update the widgets which can dock with it from the list of motion builder child dock widgets
        """
        dockWindows = {wid.windowTitle():wid for wid in self._mobuWindow.children() if isinstance(wid, QtGui.QDockWidget)}
        dockWindows.pop("Viewer") # Remove the viewer at all costs!!
        for win in dockWindows.itervalues():
            if win not in self._dockWidge:
                self._setupMobuDockWidget(win)

    def _setupMobuDockWidget(self, dockWidget):
        """
        Internal Method

        Setup a given dockwidget to work with the secondary dock

        Args:
            dockWidget (QDockWidget): A dock widget to dock with the secondary dock
        """
        QPrint(dockWidget.windowTitle())
        dockWidget.setAllowedAreas(QtCore.Qt.AllDockWidgetAreas)
        dockWidget.installEventFilter(self)
        self._dockWidge.append(dockWidget)

    def eventFilter(self, target, event):
        """
        Reimplemeted

        Qt's Event filter method for filtering out event methods which get triggered

        Args:
            target (QObject): The object which the filter is installed on
            event (QEvent): The triggering event

        Returns:
            bool
        """
        returnVal = None
        if (self._dockWidgetLastEventDict.get(target, None), event.type()) in self._mouseReleaseEventCalls:
            self._reparent(target)
            returnVal = True
        self._dockWidgetLastEventDict[target] = event.type()

        if returnVal  is not None:
            return returnVal

        return super(QtGui.QDockWidget, target).eventFilter(target, event)

    def _reparent(self, dockWidget):
        """
        Reparents the given dock widget based off its over the secondary dock widget or not

        Args:
            dockWidget (QDockWidget): The dock widget to re-parent if needed
        """
        currentParent = dockWidget.parent()
        parent = (self._mobuWindow, self)[self._isUnderCursor(self)]

        # The instance of the mobu QMainWindow never seems to be
        # the same, so a safer approach is to compare window titles
        if currentParent.windowTitle() != parent.windowTitle():
            # We set floating to True to cancel out any docking
            # Changing the parent when docking results in crashes
            dockWidget.setFloating(True)
            dockWidget.setParent(parent)
            # We call show and setFloating to True to make sure
            # the widget is visible
            dockWidget.show()
            dockWidget.setFloating(True)

    def _isUnderCursor(self, widget):
        """
        Checks if the mouse is under the given widget

        Arguments:
            widget (QWidget): widget to check
        """
        pos = QtGui.QCursor.pos()
        corner = widget.pos()
        size = widget.size()
        isInHorizontalBoundary = corner.x() <= pos.x() <= (corner.x() + size.width())
        isInVerticalBoundary = corner.y() <= pos.y() <= (corner.y() + size.height())
        return isInHorizontalBoundary and isInVerticalBoundary


# Make sure there is only one instance of the widget open
thisModule = sys.modules[__name__]
if not hasattr(thisModule, "_secondaryDockableWindow"):
    setattr(thisModule, "_secondaryDockableWindow", None)

def Run(show=True):
    thisModule = sys.modules[__name__]
    win = getattr(thisModule, "_secondaryDockableWindow")
    if _secondaryDockableWindow is None:
        win = SecondDockableWindow()
        setattr(thisModule, "_secondaryDockableWindow", win)
    else:
        win.updateDockWidgets()

    if show:
        win.show()

    return win