# Copyright (C) 2009, Tutorius.org
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
"""
This module defines Actions that can be done and undone on a state
"""
from gettext import gettext as _

from sugar.tutorius import gtkutils
from dialog import TutoriusDialog
import overlayer
from sugar.tutorius.editor import WidgetIdentifier
from sugar.tutorius.services import ObjectStore


class Action(object):
    """Base class for Actions"""
    def __init__(self):
        object.__init__(self)

    def do(self, **kwargs):
        """
        Perform the action
        """
        raise NotImplementedError("Not implemented")

    def undo(self):
        """
        Revert anything the action has changed
        """
        pass #Should raise NotImplemented?


class OnceWrapper(object):
    """
    Wraps a class to perform an action once only

    This ConcreteActions's do() method will only be called on the first do()
    and the undo() will be callable after do() has been called
    """
    def __init__(self, action):
        self._action = action
        self._called = False
        self._need_undo = False

    def do(self):
        """
        Do the action only on the first time
        """
        if not self._called:
            self._called = True
            self._action.do()
            self._need_undo = True

    def undo(self):
        """
        Undo the action if it's been done
        """
        if self._need_undo:
            self._action.undo()
            self._need_undo = False

class DialogMessage(Action):
    """
    Shows a dialog with a given text, at the given position on the screen.

    @param message A string to display to the user
    @param pos A list of the form [x, y]
    """
    def __init__(self, message, pos=[0,0]):
        super(DialogMessage, self).__init__()
        self._message = message
        self.position = pos
        self._dialog = None

    def do(self):
        """
            Show the dialog
        """
        self._dialog = TutoriusDialog(self._message)
        self._dialog.set_button_clicked_cb(self._dialog.close_self)
        self._dialog.set_modal(False)
        self._dialog.move(self.position[0], self.position[1])
        self._dialog.show()

    def undo(self):
        """
            Destroy the dialog
        """
        if self._dialog:
            self._dialog.destroy()
            self._dialog = None


class BubbleMessage(Action):
    """
    Shows a dialog with a given text, at the given position on the screen.

    @param message A string to display to the user
    @param pos A list of the form [x, y]
    @param speaker treeish representation of the speaking widget
    """
    def __init__(self, message, pos=[0,0], speaker=None, tailpos=None):
        Action.__init__(self)
        self._message = message
        self.position = pos

        self.overlay = None
        self._bubble = None
        self._speaker = None
        self._tailpos = tailpos


    def do(self):
        """
            Show the dialog
        """
        # get or inject overlayer
        self.overlay = ObjectStore().activity._overlayer
        # FIXME: subwindows, are left to overlap this. This behaviour is
        # undesirable. subwindows (i.e. child of top level windows) should be
        # handled either by rendering over them, or by finding different way to
        # draw the overlay.

        if not self._bubble:
            x, y = self.position
            # TODO: tails are relative to tailpos. They should be relative to
            # the speaking widget. Same of the bubble position.
            self._bubble = overlayer.TextBubble(text=self._message,
                tailpos=self._tailpos)
            self._bubble.show()
            self.overlay.put(self._bubble, x, y)
            self.overlay.queue_draw()

    def undo(self):
        """
            Destroy the dialog
        """
        if self._bubble:
            self._bubble.destroy()
            self._bubble = None
        
class WidgetIdentifyAction(Action):
    def __init__(self):
        self.activity = None
        self._dialog = None

    def do(self):
        os = ObjectStore()
        if os.activity:
            self.activity = os.activity

            self._dialog = WidgetIdentifier(self.activity)
            self._dialog.show()


    def undo(self):
        if self._dialog:
            self._dialog.destroy()