# -*- coding: utf-8 -*-
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.metrics import dp
from kivy.properties import ListProperty, StringProperty, OptionProperty
from kivy.uix.boxlayout import BoxLayout
from kivymd.backgroundcolorbehavior import BackgroundColorBehavior
from kivymd.button import MDIconButton
from kivymd.theming import ThemableBehavior
from kivymd.elevationbehavior import ElevationBehavior

Builder.load_string('''
#:import m_res kivymd.material_resources
<Toolbar>
    size_hint_y: None
    height: root.theme_cls.standard_increment
    background_color: root.background_color
    padding: [root.theme_cls.horizontal_margins - dp(12), 0]
    opposite_colors: True
    elevation: 6
    BoxLayout:
        id: left_actions
        orientation: 'horizontal'
        size_hint_x: None
        padding: [0, (self.height - dp(48))/2]
    BoxLayout:
        padding: dp(12), 0
        MDLabel:
            font_style: 'Title'
            opposite_colors: root.opposite_colors
            theme_text_color: root.title_theme_color
            text_color: root.title_color
            text: root.title
            shorten: True
            shorten_from: 'right'
    BoxLayout:
        id: right_actions
        orientation: 'horizontal'
        size_hint_x: None
        padding: [0, (self.height - dp(48))/2]
''')


class Toolbar(ThemableBehavior, ElevationBehavior, BackgroundColorBehavior,
              BoxLayout):
    left_action_items = ListProperty()
    """The icons on the left of the Toolbar.

    To add one, append a list like the following:

        ['icon_name', callback]

    where 'icon_name' is a string that corresponds to an icon definition and
     callback is the function called on a touch release event.
    """

    right_action_items = ListProperty()
    """The icons on the left of the Toolbar.

    Works the same way as :attr:`left_action_items`
    """

    title = StringProperty()
    """The text displayed on the Toolbar."""

    title_theme_color = OptionProperty(None, allownone=True,
                                       options=['Primary', 'Secondary', 'Hint',
                                                'Error', 'Custom'])

    title_color = ListProperty(None, allownone=True)

    background_color = ListProperty([0, 0, 0, 1])

    def __init__(self, **kwargs):
        super(Toolbar, self).__init__(**kwargs)
        Clock.schedule_once(
            lambda x: self.on_left_action_items(0, self.left_action_items))
        Clock.schedule_once(
            lambda x: self.on_right_action_items(0,
                                                 self.right_action_items))

    def on_left_action_items(self, instance, value):
        self.update_action_bar(self.ids['left_actions'], value)

    def on_right_action_items(self, instance, value):
        self.update_action_bar(self.ids['right_actions'], value)

    def update_action_bar(self, action_bar, action_bar_items):
        action_bar.clear_widgets()
        new_width = 0
        for item in action_bar_items:
            new_width += dp(48)
            action_bar.add_widget(MDIconButton(icon=item[0],
                                               on_release=item[1],
                                               opposite_colors=True,
                                               text_color=self.title_color,
                                               theme_text_color=self.title_theme_color))
        action_bar.width = new_width