########################################################################################################################
#    File: menus.py
# Purpose: Creates a menubar with submenus for Tkinter GUI
#  Author: Dan Huckson, https://github.com/unodan
#    Date: 2018-05-21
########################################################################################################################
from tkinter import *


def label_underline(label):
    position = label.find('&')
    if position >= 0:
        label = label[:position] + label[position + 1:]

    return label, position


class MenuItem:
    def __init__(self, menu, item, **kwargs):
        self.__parent = menu
        self.__attributes = {}

        fg = self.__attributes['fg'] = kwargs.pop('fg', None)
        bg = self.__attributes['bg'] = kwargs.pop('bg', None)
        font = self.__attributes['font'] = kwargs.pop('font', None)
        activeforeground = self.__attributes['activeforeground'] = kwargs.pop('activeforeground', None)
        activebackground = self.__attributes['activebackground'] = kwargs.pop('activebackground', None)

        index = kwargs.pop('index', None)
        image = self.__attributes['image'] = item[1]
        accelerator = self.__attributes['accelerator'] = item[2]
        command = self.__attributes['command'] = None if len(item) < 4 and not len(item) > 4 else item[3]
        state = self.__attributes['state'] = 'normal' if len(item) < 5 else item[4]

        label, underline = label_underline(item[0])
        self.__attributes['label'] = self.__index = label

        if label == '--sep--':
            menu.add_separator()
        else:
            menu_command = menu.insert if isinstance(item[2], tuple) else menu.add_command
            menu_command(
                index=index,
                state=state,
                command=command,
                font=font,
                label=label,
                image=image,
                compound='left',
                foreground=fg,
                background=bg,
                underline=underline,
                accelerator=accelerator,
                activeforeground=activeforeground,
                activebackground=activebackground,
            )

    def cget(self, index):
        return self.__attributes.get(index, None)

    def config(self, **kwargs):
        fg = kwargs.pop('fg', None)
        if fg:
            self.__attributes['fg'] = fg

        bg = kwargs.pop('bg', None)
        if bg:
            self.__attributes['bg'] = bg

        font = kwargs.pop('font', None)
        if font:
            self.__attributes['font'] = font

        label = kwargs.pop('label', None)
        if label:
            self.__index = label
            self.__attributes['label'] = label

        image = kwargs.pop('image', None)
        if image:
            self.__attributes['image'] = image

        state = kwargs.pop('state', None)
        if state:
            self.__attributes['state'] = state

        underline = kwargs.pop('underline', None)
        if underline:
            self.__attributes['underline'] = underline

        accelerator = kwargs.pop('accelerator', None)
        if accelerator:
            self.__attributes['accelerator'] = accelerator

        activeforeground = kwargs.pop('activeforeground', None)
        if activeforeground:
            self.__attributes['activeforeground'] = activeforeground

        activebackground = kwargs.pop('activebackground', None)
        if activebackground:
            self.__attributes['activebackground'] = activebackground

        self.__parent.entryconfig(
            self.__index,
            font=font,
            label=label,
            image=image,
            state=state,
            compound='left',
            foreground=fg,
            background=bg,
            underline=underline,
            accelerator=accelerator,
            activeforeground=activeforeground,
            activebackground=activebackground,
        )


class Menus(Menu):
    def __init__(self, parent, *args, **kwargs):
        super(Menus, self).__init__(parent, *args, **kwargs)

        self.__items = {}
        self.__parent = parent
        self.__index = kwargs.pop('index', None)

    def get(self, path):
        path = path.replace('\\', '/')

        if '/' in path:
            return self.item(self, path)

        return self.__items.get(path, None)

    def item(self, menu, path):
        parts = path.split('/', 1)
        member = menu.get(parts[0])

        if len(parts) > 1:
            member = self.item(member, parts[1])

        return member

    def set(self, index, value):
        if index in self.__items:
            self.__items[index] = value

    def get_items(self):
        return self.__items

    def add_items(self, item, **kwargs):

        label, underline = label_underline(item[0])

        if label in self.__items and label != '--sep--':
            return

        bd = kwargs.pop('bd', self.cget('bd'))
        fg = kwargs.pop('fg', self.cget('fg'))
        bg = kwargs.pop('bg', self.cget('bg'))
        font = kwargs.pop('font', self.cget('font'))
        tearoff = kwargs.pop('tearoff', self.cget('tearoff'))
        activeforeground = kwargs.pop('activeforeground', self.cget('activeforeground'))
        activebackground = kwargs.pop('activebackground', self.cget('activebackground'))

        index = kwargs.pop('index', self.__index)

        menu_command = SubMenu if isinstance(item[2], tuple) else MenuItem
        self.__items[label] = menu_command(
            self,
            item,
            bd=bd,
            fg=fg,
            bg=bg,
            font=font,
            index=index,
            tearoff=tearoff,
            activeforeground=activeforeground,
            activebackground=activebackground,
        )

    def populate(self, menus):
        if menus:
            for item in menus:
                self.add_items(item)


class SubMenu(Menus):
    def __init__(self, parent, menu, *args, **kwargs):
        index = kwargs.pop('index', None)
        super().__init__(parent, *args, **kwargs)

        bd = kwargs.pop('bd', self.cget('bd'))
        fg = kwargs.pop('fg', self.cget('fg'))
        bg = kwargs.pop('bg', self.cget('bg'))
        font = kwargs.pop('font', self.cget('font'))
        tearoff = kwargs.pop('tearoff', self.cget('tearoff'))
        activeforeground = kwargs.pop('activeforeground', self.cget('activeforeground'))
        activebackground = kwargs.pop('activebackground', self.cget('activebackground'))

        image = menu[1]
        items = None if len(menu) < 3 and not len(menu) > 3 else menu[2]
        state = 'normal' if len(menu) < 4 else menu[3]

        self.__items = {}
        label, underline = label_underline(menu[0])

        menu_command = parent.add_cascade if index is None else parent.insert_cascade
        menu_command(index, label=label, image=image, compound='left', menu=self, state=state, underline=underline)

        item_names = []
        for item in items:
            if item[0] in item_names and item[0] != '--sep--':
                continue

            label = item[0]
            position = label.find('&')
            if position != -1:
                label = label[:position] + label[position + 1:]

            menu_command = SubMenu if isinstance(item[2], tuple) else MenuItem

            item_names.append(label)
            self.__items[label] = menu_command(
                self,
                item,
                bd=bd,
                fg=fg,
                bg=bg,
                font=font,
                tearoff=tearoff,
                activeforeground=activeforeground,
                activebackground=activebackground,
            )

    def get(self, path):
        path = path.replace('\\', '/')

        if '/' in path:
            return self.item(self, path)

        return self.__items.get(path, None)


class MenuBar(Menus):
    def __init__(self, parent, *args, **kwargs):
        super().__init__(parent, *args, **kwargs)

        self.__items = {}


class PopupMenu(Menus):
    def __init__(self, parent, *args, **kwargs):
        super().__init__(parent, *args, **kwargs)

        self.__items = {}
        self.__leave = False
        self.__delay_destroy = 1000
        self.bind("<Enter>", self.on_enter)
        self.bind("<Leave>", self.on_leave)
        self.bind("<Escape>", self.on_escape)

    def on_enter(self, event):
        self.__leave = False

    def on_leave(self, event):
        self.__leave = True

        def leave():
            if self.__leave:
                self.on_escape(event)

        self.after(self.__delay_destroy, leave)

    def on_escape(self, event):
        self.unpost()
        self.__leave = False