#------------------------------------------------------------------------------
#
#  Copyright (c) 2005, Enthought, Inc.
#  All rights reserved.
#
#  This software is provided without warranty under the terms of the BSD
#  license included in enthought/LICENSE.txt and may be redistributed only
#  under the conditions described in the aforementioned license.  The license
#  is also available online at http://www.enthought.com/licenses/BSD.txt
#
#  Thanks for using Enthought open source!
#
#  Author: David C. Morrill
#  Date:   10/21/2004
#
#------------------------------------------------------------------------------

""" Defines the various editors for single-selection enumerations, for the
wxPython user interface toolkit.
"""

#-------------------------------------------------------------------------
#  Imports:
#-------------------------------------------------------------------------

from __future__ import absolute_import
import wx

from traits.api \
    import Property

# FIXME: ToolkitEditorFactory is a proxy class defined here just for backward
# compatibility. The class has been moved to the
# traitsui.editors.drop_editor file.
from traitsui.editors.enum_editor \
    import ToolkitEditorFactory

from .editor \
    import Editor

from .constants \
    import OKColor, ErrorColor

from .helper \
    import enum_values_changed, TraitsUIPanel, disconnect, disconnect_no_id
from functools import reduce


# default formatting function (would import from string, but not in Python 3)
capitalize = lambda s: s.capitalize()


#-------------------------------------------------------------------------
#  'BaseEditor' class:
#-------------------------------------------------------------------------

class BaseEditor(Editor):
    """ Base class for enumeration editors.
    """

    #-------------------------------------------------------------------------
    #  Trait definitions:
    #-------------------------------------------------------------------------

    # Current set of enumeration names:
    names = Property

    # Current mapping from names to values:
    mapping = Property

    # Current inverse mapping from values to names:
    inverse_mapping = Property

    #-------------------------------------------------------------------------
    #  Finishes initializing the editor by creating the underlying toolkit
    #  widget:
    #-------------------------------------------------------------------------

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        factory = self.factory
        if factory.name != '':
            self._object, self._name, self._value = \
                self.parse_extended_name(factory.name)
            self.values_changed()
            self._object.on_trait_change(self._values_changed,
                                         ' ' + self._name, dispatch='ui')
        else:
            factory.on_trait_change(self.rebuild_editor, 'values_modified',
                                    dispatch='ui')

    #-------------------------------------------------------------------------
    #  Gets the current set of enumeration names:
    #-------------------------------------------------------------------------

    def _get_names(self):
        """ Gets the current set of enumeration names.
        """
        if self._object is None:
            return self.factory._names

        return self._names

    #-------------------------------------------------------------------------
    #  Gets the current mapping:
    #-------------------------------------------------------------------------

    def _get_mapping(self):
        """ Gets the current mapping.
        """
        if self._object is None:
            return self.factory._mapping

        return self._mapping

    #-------------------------------------------------------------------------
    #  Gets the current inverse mapping:
    #-------------------------------------------------------------------------

    def _get_inverse_mapping(self):
        """ Gets the current inverse mapping.
        """
        if self._object is None:
            return self.factory._inverse_mapping

        return self._inverse_mapping

    #-------------------------------------------------------------------------
    #  Rebuilds the contents of the editor whenever the original factory
    #  object's 'values' trait changes:
    #-------------------------------------------------------------------------

    def rebuild_editor(self):
        """ Rebuilds the contents of the editor whenever the original factory
            object's **values** trait changes.
        """
        raise NotImplementedError

    #-------------------------------------------------------------------------
    #  Recomputes the cached data based on the underlying enumeration model:
    #-------------------------------------------------------------------------

    def values_changed(self):
        """ Recomputes the cached data based on the underlying enumeration model.
        """
        self._names, self._mapping, self._inverse_mapping = \
            enum_values_changed(self._value())

    #-------------------------------------------------------------------------
    #  Handles the underlying object model's enumeration set being changed:
    #-------------------------------------------------------------------------

    def _values_changed(self):
        """ Handles the underlying object model's enumeration set being changed.
        """
        self.values_changed()
        self.rebuild_editor()

    #-------------------------------------------------------------------------
    #  Disposes of the contents of an editor:
    #-------------------------------------------------------------------------

    def dispose(self):
        """ Disposes of the contents of an editor.
        """
        if self._object is not None:
            self._object.on_trait_change(self._values_changed,
                                         ' ' + self._name, remove=True)
        else:
            self.factory.on_trait_change(self.rebuild_editor,
                                         'values_modified', remove=True)

        super(BaseEditor, self).dispose()

#-------------------------------------------------------------------------
#  'SimpleEditor' class:
#-------------------------------------------------------------------------


class SimpleEditor(BaseEditor):
    """ Simple style of enumeration editor, which displays a combo box.
    """

    #-------------------------------------------------------------------------
    #  Finishes initializing the editor by creating the underlying toolkit
    #  widget:
    #-------------------------------------------------------------------------

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        super(SimpleEditor, self).init(parent)

        factory = self.factory

        if factory.evaluate is None:
            self.control = control = wx.Choice(parent, -1, wx.Point(0, 0),
                                               wx.Size(-1, -1), self.names)
            wx.EVT_CHOICE(parent, self.control.GetId(), self.update_object)
        else:
            self.control = control = wx.ComboBox(parent, -1, '',
                                                 wx.Point(0, 0), wx.Size(-1, -1), self.names,
                                                 style=wx.CB_DROPDOWN)
            wx.EVT_COMBOBOX(parent, control.GetId(), self.update_object)
            wx.EVT_TEXT_ENTER(parent, control.GetId(),
                              self.update_text_object)
            wx.EVT_KILL_FOCUS(control, self.on_kill_focus)

            if (not factory.is_grid_cell) and factory.auto_set:
                wx.EVT_TEXT(parent, control.GetId(), self.update_text_object)

        self._no_enum_update = 0
        self.set_tooltip()

    def dispose(self):
        """ Disposes of the contents of an editor.
        """
        disconnect(self.control,
                   wx.EVT_COMBOBOX, wx.EVT_TEXT_ENTER, wx.EVT_TEXT)

        disconnect_no_id(self.control, wx.EVT_KILL_FOCUS)

        super(SimpleEditor, self).dispose()

    #-------------------------------------------------------------------------
    #  Handles the user selecting a new value from the combo box:
    #-------------------------------------------------------------------------

    def update_object(self, event):
        """ Handles the user selecting a new value from the combo box.
        """
        self._no_enum_update += 1
        try:
            new_value = self.mapping[event.GetString()]
            if new_value == self.value and self.factory.is_grid_cell:
                # If the enum editor is in a grid cell and the value did not
                # change, we want the enum editor to go away, reverting back to
                # the normal cell appearance. This is for 2 reasons:
                #  1. it looks nicer
                #  2. if the grid id suddenly closed, wx freaks & causes a
                #     segfault

                grid = self.control.Parent.Parent
                grid.EnableEditing(False)
                grid.EnableEditing(True)

            self.value = new_value

        except:
            from traitsui.api import raise_to_debug
            raise_to_debug()

        self._no_enum_update -= 1

    #-------------------------------------------------------------------------
    #  Handles the user typing text into the combo box text entry field:
    #-------------------------------------------------------------------------

    def update_text_object(self, event):
        """ Handles the user typing text into the combo box text entry field.
        """
        if self._no_enum_update == 0:
            value = self.control.GetValue()
            try:
                value = self.mapping[value]
            except:
                try:
                    value = self.factory.evaluate(value)
                except Exception as excp:
                    self.error(excp)
                    return

            self._no_enum_update += 1
            try:
                self.value = value
                self.control.SetBackgroundColour(OKColor)
                self.control.Refresh()
            except:
                pass
            self._no_enum_update -= 1

    #-------------------------------------------------------------------------
    #  Handles the control losing the keyboard focus:
    #-------------------------------------------------------------------------

    def on_kill_focus(self, event):
        """ Handles the control losing the keyboard focus.
        """
        self.update_text_object(event)
        event.Skip()

    #-------------------------------------------------------------------------
    #  Updates the editor when the object trait changes external to the editor:
    #-------------------------------------------------------------------------

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        if self._no_enum_update == 0:
            if self.factory.evaluate is None:
                try:
                    self.control.SetStringSelection(
                        self.inverse_mapping[self.value])
                except:
                    pass
            else:
                try:
                    self.control.SetValue(self.str_value)
                except:
                    pass

    #-------------------------------------------------------------------------
    #  Handles an error that occurs while setting the object's trait value:
    #-------------------------------------------------------------------------

    def error(self, excp):
        """ Handles an error that occurs while setting the object's trait value.
        """
        self.control.SetBackgroundColour(ErrorColor)
        self.control.Refresh()

    #-------------------------------------------------------------------------
    #  Rebuilds the contents of the editor whenever the original factory
    #  object's 'values' trait changes:
    #-------------------------------------------------------------------------

    def rebuild_editor(self):
        """ Rebuilds the contents of the editor whenever the original factory
            object's **values** trait changes.
        """
        # Note: This code is unnecessarily complex due to a strange bug in
        # wxWidgets implementation of the wx.Combobox control that has strange
        # behavior when the current text field value is one of the selection
        # values when 'Clear' is called. In this case, even saving and
        # restoring the text field value does not work, so we go to great
        # lengths to detect this case and avoid using 'Clear', but still get
        # the equivalent visual results. Modify this code at your own risk...

        control = self.control
        clear = True
        cur_name = None
        if self.factory.evaluate is not None:
            n = control.GetCount()
            cur_names = [control.GetString(i) for i in range(n)]
            cur_name = control.GetValue()
            if cur_name in self.names:
                clear = False
                include = True
                for i in range(n - 1, -1, -1):
                    if cur_name == cur_names[i]:
                        include = False
                    else:
                        control.Delete(i)
                for name in self.names:
                    if include or (name != cur_name):
                        control.Append(name)
                cur_name = None
            else:
                point = control.GetInsertionPoint()

        if clear:
            control.Clear()
            control.AppendItems(self.names)

        if cur_name is not None:
            self._no_enum_update += 1
            control.SetValue(cur_name)
            control.SetInsertionPoint(point)
            self._no_enum_update -= 1

        self.update_editor()

#-------------------------------------------------------------------------
#  'RadioEditor' class:
#-------------------------------------------------------------------------


class RadioEditor(BaseEditor):
    """ Enumeration editor, used for the "custom" style, that displays radio
        buttons.
    """

    #-------------------------------------------------------------------------
    #  Finishes initializing the editor by creating the underlying toolkit
    #  widget:
    #-------------------------------------------------------------------------

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        super(RadioEditor, self).init(parent)

        # Create a panel to hold all of the radio buttons:
        self.control = TraitsUIPanel(parent, -1)
        self.rebuild_editor()

    #-------------------------------------------------------------------------
    #  Handles the user clicking one of the 'custom' radio buttons:
    #-------------------------------------------------------------------------

    def update_object(self, event):
        """ Handles the user clicking one of the custom radio buttons.
        """
        try:
            self.value = event.GetEventObject().value
        except:
            pass

    #-------------------------------------------------------------------------
    #  Updates the editor when the object trait changes external to the editor:
    #-------------------------------------------------------------------------

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        value = self.value
        for button in self.control.GetChildren():
            state = (button.value == value)
            button.SetValue(state)
            if state:
                button.SetFocus()

    #-------------------------------------------------------------------------
    #  Rebuilds the contents of the editor whenever the original factory
    #  object's 'values' trait changes:
    #-------------------------------------------------------------------------

    def rebuild_editor(self):
        """ Rebuilds the contents of the editor whenever the original factory
            object's **values** trait changes.
        """
        # Clear any existing content:
        panel = self.control
        panel.SetSizer(None)
        panel.DestroyChildren()

        # Get the current trait value:
        cur_name = self.str_value

        # Create a sizer to manage the radio buttons:
        names = self.names
        mapping = self.mapping
        n = len(names)
        cols = self.factory.cols
        rows = (n + cols - 1) / cols
        incr = [n / cols] * cols
        rem = n % cols
        for i in range(cols):
            incr[i] += (rem > i)
        incr[-1] = -(reduce(lambda x, y: x + y, incr[:-1], 0) - 1)
        if cols > 1:
            sizer = wx.GridSizer(0, cols, 2, 4)
        else:
            sizer = wx.BoxSizer(wx.VERTICAL)

        # Add the set of all possible choices:
        style = wx.RB_GROUP
        index = 0
        for i in range(rows):
            for j in range(cols):
                if n > 0:
                    name = label = names[index]
                    label = self.string_value(label, capitalize)
                    control = wx.RadioButton(panel, -1, label, style=style)
                    control.value = mapping[name]
                    style = 0
                    control.SetValue(name == cur_name)
                    wx.EVT_RADIOBUTTON(panel, control.GetId(),
                                       self.update_object)
                    self.set_tooltip(control)
                    index += incr[j]
                    n -= 1
                else:
                    control = wx.RadioButton(panel, -1, '')
                    control.value = ''
                    control.Show(False)
                sizer.Add(control, 0, wx.NORTH, 5)

        # Set-up the layout:
        panel.SetSizerAndFit(sizer)

#-------------------------------------------------------------------------
#  'ListEditor' class:
#-------------------------------------------------------------------------


class ListEditor(BaseEditor):
    """ Enumeration editor, used for the "custom" style, that displays a list
        box.
    """

    #-------------------------------------------------------------------------
    #  Finishes initializing the editor by creating the underlying toolkit
    #  widget:
    #-------------------------------------------------------------------------

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        super(ListEditor, self).init(parent)

        # Create a panel to hold all of the radio buttons:
        self.control = wx.ListBox(parent, -1, wx.Point(0, 0),
                                  wx.Size(-1, -1), self.names,
                                  style=wx.LB_SINGLE | wx.LB_NEEDED_SB)
        wx.EVT_LISTBOX(parent, self.control.GetId(), self.update_object)
        self.set_tooltip()

    def dispose(self):
        """ Disposes of the contents of an editor.
        """
        disconnect(self.control, wx.EVT_LISTBOX)

        super(ListEditor, self).dispose()

    #-------------------------------------------------------------------------
    #  Handles the user selecting a list box item:
    #-------------------------------------------------------------------------

    def update_object(self, event):
        """ Handles the user selecting a list box item.
        """
        if not self._ignore_update:
            value = self.control.GetStringSelection()
            try:
                value = self.mapping[value]
            except:
                try:
                    value = self.factory.evaluate(value)
                except:
                    pass
            try:
                self.value = value
            except:
                pass

    #-------------------------------------------------------------------------
    #  Updates the editor when the object trait changes external to the editor:
    #-------------------------------------------------------------------------

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        control = self.control
        try:
            index = control.FindString(self.inverse_mapping[self.value])
            if index >= 0:
                control.SetSelection(index)
        except:
            pass

    #-------------------------------------------------------------------------
    #  Rebuilds the contents of the editor whenever the original factory
    #  object's 'values' trait changes:
    #-------------------------------------------------------------------------

    def rebuild_editor(self):
        """ Rebuilds the contents of the editor whenever the original factory
            object's **values** trait changes.
        """
        self._ignore_update = True
        self.control.Clear()
        self.control.AppendItems(self.names)
        self._ignore_update = False

        # fixme: Is this line necessary?
        self.update_editor()

### EOF #######################################################################