from tkinter import ttk, Frame, Canvas
from PIL import Image, ImageDraw
from tkinter import PhotoImage
import io

class View(Frame):

    def __init__(self, *args, tare_command=None, calibrate_command=None, **kwargs):
        super().__init__(*args, **kwargs)

        self.actions = Frame(self)
        self.actions.pack()
        self.calibrate_button = ttk.Button(self.actions, text="Calibrate", command=calibrate_command)
        self.calibrate_button.pack()
        self.tare_button = ttk.Button(self.actions, text="Tare", command=tare_command)
        self.tare_button.pack()
        
        self.size = (168, 144)
        self.center = (168 // 2, 144 // 2)
        self.bkg_im = self._init_im()
        self._init_ui()

        self.canvas = Canvas(self, width=168, height=144, background='white',
                             highlightthickness=1, highlightbackground="black")
        self.canvas.pack()

        self.refresh(0.0)
    
    def _init_ui(self):
        pass

    def _init_im(self):
        return Image.new('1', self.size, 'white')
    
    def update_weight(self,
                      weight: float) -> None:
        raise NotImplementedError()
    
    def refresh(self, weight: float):
        # draw weight on bkg_im
        im = self.update_weight(weight)

        # Convert PIL image to bytes
        buffer = io.BytesIO()
        im.save(buffer, format='PNG')
        buffer.seek(0)
        
        # Load into PhotoImage and display on canvas
        self.photo = PhotoImage(data=buffer.getvalue())
        self.canvas.delete("all")
        self.canvas.create_image(0, 0, anchor="nw", image=self.photo)