#------------------------------------------------------------------------------
#  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:   01/24/2002
#
#------------------------------------------------------------------------------

""" Dynamically construct wxPython Menus or MenuBars from a supplied string
    description of the menu.

Menu Description Syntax::

    submenu_label {help_string}
        menuitem_label | accelerator {help_string} [~/-name]: code

*submenu_label*
    Label of a sub menu
*menuitem_label*
    Label of a menu item
{*help_string*}
    Help string to display on the status line (optional)
*accelerator*
    Accelerator key (e.g., Ctrl-C) (The '|' and keyname are optional, but must
    be used together.)
[~]
    The menu item is checkable, but is not checked initially (optional)
[/]
    The menu item is checkable, and is checked initially (optional)
[-]
    The menu item disabled initially (optional)
[*name*]
    Symbolic name used to refer to menu item (optional)
*code*
    Python code invoked when menu item is selected

A line beginning with a hyphen (-) is interpreted as a menu separator.
"""

#=========================================================================
#  Imports:
#=========================================================================

from __future__ import absolute_import, print_function

import wx
import re
import string
import six

#=========================================================================
#  Constants:
#=========================================================================

help_pat = re.compile(r'(.*){(.*)}(.*)')
options_pat = re.compile(r'(.*)\[(.*)\](.*)')

# Mapping of key name strings to wxPython key codes
key_map = {
    'F1': wx.WXK_F1,
    'F2': wx.WXK_F2,
    'F3': wx.WXK_F3,
    'F4': wx.WXK_F4,
    'F5': wx.WXK_F5,
    'F6': wx.WXK_F6,
    'F7': wx.WXK_F7,
    'F8': wx.WXK_F8,
    'F9': wx.WXK_F9,
    'F10': wx.WXK_F10,
    'F11': wx.WXK_F11,
    'F12': wx.WXK_F12
}

#-------------------------------------------------------------------------
#  'MakeMenu' class:
#-------------------------------------------------------------------------


class MakeMenu:
    """ Manages creation of menus.
    """
    # Initialize the globally unique menu ID:
    cur_id = 1000

    #-------------------------------------------------------------------------
    #  Initializes the object:
    #-------------------------------------------------------------------------

    def __init__(self, desc, owner, popup=False, window=None):
        """ Initializes the object.
        """
        self.owner = owner
        if window is None:
            window = owner
        self.window = window
        self.indirect = getattr(owner, 'call_menu', None)
        self.names = {}
        self.desc = desc.split('\n')
        self.index = 0
        self.keys = []
        if popup:
            self.menu = menu = wx.Menu()
            self.parse(menu, -1)
        else:
            self.menu = menu = wx.MenuBar()
            self.parse(menu, -1)
            window.SetMenuBar(menu)
            if len(self.keys) > 0:
                window.SetAcceleratorTable(wx.AcceleratorTable(self.keys))

    #-------------------------------------------------------------------------
    #  Recursively parses menu items from the description:
    #-------------------------------------------------------------------------

    def parse(self, menu, indent):
        """ Recursively parses menu items from the description.
        """

        while True:

            # Make sure we have not reached the end of the menu description
            # yet:
            if self.index >= len(self.desc):
                return

            # Get the next menu description line and check its indentation:
            dline = self.desc[self.index]
            line = dline.lstrip()
            indented = len(dline) - len(line)
            if indented <= indent:
                return

            # Indicate that the current line has been processed:
            self.index += 1

            # Check for a blank or comment line:
            if (line == '') or (line[0:1] == '#'):
                continue

            # Check for a menu separator:
            if line[0:1] == '-':
                menu.AppendSeparator()
                continue

            # Allocate a new menu ID:
            MakeMenu.cur_id += 1
            cur_id = MakeMenu.cur_id

            # Extract the help string (if any):
            help = ''
            match = help_pat.search(line)
            if match:
                help = ' ' + match.group(2).strip()
                line = match.group(1) + match.group(3)

            # Check for a menu item:
            col = line.find(':')
            if col >= 0:
                handler = line[col + 1:].strip()
                if handler != '':
                    if self.indirect:
                        self.indirect(cur_id, handler)
                        handler = self.indirect
                    else:
                        try:
                            exec (
                                'def handler(event,self=self.owner):\n %s\n' %
                                handler)
                        except:
                            handler = null_handler
                else:
                    try:
                        exec('def handler(event,self=self.owner):\n%s\n' % (
                            self.get_body(indented), ), globals())
                    except:
                        handler = null_handler
                wx.EVT_MENU(self.window, cur_id, handler)
                not_checked = checked = disabled = False
                line = line[: col]
                match = options_pat.search(line)
                if match:
                    line = match.group(1) + match.group(3)
                    not_checked, checked, disabled, name = option_check(
                        '~/-', match.group(2).strip())
                    if name != '':
                        self.names[name] = cur_id
                        setattr(self.owner, name, MakeMenuItem(self, cur_id))
                label = line.strip()
                col = label.find('|')
                if col >= 0:
                    key = label[col + 1:].strip()
                    label = '%s%s%s' % (label[: col].strip(), '\t', key)
                    key = key.upper()
                    flag = wx.ACCEL_NORMAL
                    col = key.find('-')
                    if col >= 0:
                        flag = {'CTRL': wx.ACCEL_CTRL,
                                'SHIFT': wx.ACCEL_SHIFT,
                                'ALT': wx.ACCEL_ALT
                                }.get(key[: col].strip(), wx.ACCEL_CTRL)
                        key = key[col + 1:].strip()
                    code = key_map.get(key, None)
                    try:
                        if code is None:
                            code = ord(key)
                        self.keys.append(
                            wx.AcceleratorEntry(flag, code, cur_id))
                    except:
                        pass
                menu.Append(cur_id, label, help, not_checked or checked)
                if checked:
                    menu.Check(cur_id, True)
                if disabled:
                    menu.Enable(cur_id, False)
                continue

            # Else must be the start of a sub menu:
            submenu = wx.Menu()
            label = line.strip()

            # Recursively parse the sub-menu:
            self.parse(submenu, indented)

            # Add the menu to its parent:
            try:
                menu.AppendMenu(cur_id, label, submenu, help)
            except:
                # Handle the case where 'menu' is really a 'MenuBar' (which does
                # not understand 'MenuAppend'):
                menu.Append(submenu, label)

    #-------------------------------------------------------------------------
    #  Returns the body of an inline method:
    #-------------------------------------------------------------------------

    def get_body(self, indent):
        """ Returns the body of an inline method.
        """
        result = []
        while self.index < len(self.desc):
            line = self.desc[self.index]
            if (len(line) - len(line.lstrip())) <= indent:
                break
            result.append(line)
            self.index += 1
        result = '\n'.join(result).rstrip()
        if result != '':
            return result
        return '  pass'

    #-------------------------------------------------------------------------
    #  Returns the id associated with a specified name:
    #-------------------------------------------------------------------------

    def get_id(self, name):
        """ Returns the ID associated with a specified name.
        """
        if isinstance(name, six.string_types):
            return self.names[name]
        return name

    #-------------------------------------------------------------------------
    #  Checks (or unchecks) a menu item specified by name:
    #-------------------------------------------------------------------------

    def checked(self, name, check=None):
        """ Checks (or unchecks) a menu item specified by name.
        """
        if check is None:
            return self.menu.IsChecked(self.get_id(name))
        self.menu.Check(self.get_id(name), check)

    #-------------------------------------------------------------------------
    #  Enables (or disables) a menu item specified by name:
    #-------------------------------------------------------------------------

    def enabled(self, name, enable=None):
        """ Enables (or disables) a menu item specified by name.
        """
        if enable is None:
            return self.menu.IsEnabled(self.get_id(name))
        self.menu.Enable(self.get_id(name), enable)

    #-------------------------------------------------------------------------
    #  Gets/Sets the label for a menu item:
    #-------------------------------------------------------------------------

    def label(self, name, label=None):
        """ Gets or sets the label for a menu item.
        """
        if label is None:
            return self.menu.GetLabel(self.get_id(name))
        self.menu.SetLabel(self.get_id(name), label)

#-------------------------------------------------------------------------
#  'MakeMenuItem' class:
#-------------------------------------------------------------------------


class MakeMenuItem:
    """ A menu item for a menu managed by MakeMenu.
    """

    def __init__(self, menu, id):
        self.menu = menu
        self.id = id

    def checked(self, check=None):
        return self.menu.checked(self.id, check)

    def toggle(self):
        checked = not self.checked()
        self.checked(checked)
        return checked

    def enabled(self, enable=None):
        return self.menu.enabled(self.id, enable)

    def label(self, label=None):
        return self.menu.label(self.id, label)

#-------------------------------------------------------------------------
#  Determine whether a string contains any specified option characters, and
#  remove them if it does:
#-------------------------------------------------------------------------


def option_check(test, string):
    """ Determines whether a string contains any specified option characters,
    and removes them if it does.
    """
    result = []
    for char in test:
        col = string.find(char)
        result.append(col >= 0)
        if col >= 0:
            string = string[: col] + string[col + 1:]
    return result + [string.strip()]

#-------------------------------------------------------------------------
#  Null menu option selection handler:
#-------------------------------------------------------------------------


def null_handler(event):
    print('null_handler invoked')
