import kivy
kivy.require('2.0.0')
import kivymd

from kivymd.uix.screen import MDScreen
from kivymd.app import MDApp
from kivy.uix.image import Image
from kivymd.uix.button import MDFillRoundFlatIconButton, MDFillRoundFlatButton
from kivymd.uix.textfield import MDTextField
from kivymd.uix.label import MDLabel
from kivymd.uix.toolbar import MDToolbar

class ConverterApp(MDApp):

    def flip(self):
        # hide labels until needed
        self.converted.text = ""
        self.label.text = ""
        self.input.text = ""
        # a method for the "flip" icon
        # changes the state of the app
        if self.state == 0:
            self.state = 1
            self.toolbar.title = "Decimal to Binary"
            self.input.hint_text = "enter a decimal number"
        else:
            self.state = 0
            self.toolbar.title = "Binary to Decimal"
            self.input.hint_text = "enter a binary number"

    def convert(self, args):
        # a method to find the decimal/binary equivallent
        try:
            if "." not in self.input.text:
                # if the user-provided number is not a fraction
                if self.state == 0:
                    # binary to decimal
                    val = str(int(self.input.text,2))
                    self.label.text = "in decimal is:"
                else:
                    # decimal to binary
                    val = bin(int(self.input.text))[2:]
                    self.label.text = "in binary is:"
                self.converted.text = val
            else:
                #if the user provided number is a fraction
                whole, fract = self.input.text.split(".")

                if self.state == 0:
                    #convert binary to decimal
                    whole = int(whole, 2)
                    floating = 0
                    for idx, digit in enumerate(fract):
                        floating += int(digit)*2**(-(idx+1))
                    self.label.text = "in decimal is:"
                    self.converted.text = str(whole + floating)
                else:
                    #convert decimal to binary
                    decimal_places = 10
                    whole = bin(int(whole))[2:]
                    fract = float("0."+fract)
                    floating = []
                    for i in range(decimal_places):
                        if fract*2 < 1:
                            floating.append("0")
                            fract *= 2
                        elif fract*2 > 1:
                            floating.append("1")
                            fract = fract*2 - 1
                        elif fract*2 == 1.0:
                            floating.append("1")
                            break
                    self.label.text = "in binary is:"
                    self.converted.text = whole + "." + "".join(floating)
        except ValueError:
            #if the user-provided value is invalid
            self.converted.text = ""
            if self.state == 0:
                #binary to decimal
                self.label.text = "please enter a valid binary number"

            else:
                #decimal to binary
                self.label.text = "please enter a valid decimal number"

    def build(self):
        self.state = 0 #initial state
        self.theme_cls.primary_palette = "Blue"
        screen = MDScreen()

        # top toolbar
        self.toolbar = MDToolbar(title="Binary to Decimal")
        self.toolbar.pos_hint = {"top": 1}
        self.toolbar.right_action_items = [
            ["rotate-3d-variant", lambda x: self.flip()]]
        screen.add_widget(self.toolbar)

        # logo
        screen.add_widget(Image(
            source="logo.png",
            pos_hint = {"center_x": 0.5, "center_y":0.7}
            ))

        #collect user input
        self.input = MDTextField(
            size_hint = (0.8,1),
            pos_hint = {"center_x": 0.5, "center_y":0.5},
            on_text_validate = self.convert
        )
        self.input.hint_text ="enter a binary number"
        screen.add_widget(self.input)

        #secondary + primary labels
        self.label = MDLabel(
            halign="center",
            pos_hint = {"center_x": 0.5, "center_y":0.35},
            theme_text_color = "Secondary"
        )

        self.converted = MDLabel(
            halign="center",
            pos_hint = {"center_x": 0.5, "center_y":0.3},
            theme_text_color = "Primary",
            font_style = "H5"
        )
        screen.add_widget(self.label)
        screen.add_widget(self.converted)

        # "CONVERT" button
        screen.add_widget(MDFillRoundFlatButton(
            text="    CONVERT    ",
            font_size = 25,
            pos_hint = {"center_x": 0.5, "center_y":0.15},
            on_press = self.convert
        ))

        return screen

if __name__ == '__main__':
    ConverterApp().run()