import argparse
import pymupdf

import tkinter
from tkinter import ttk
from PIL import Image, ImageTk

CURRENT_PAGE = 0

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("file")
    args = parser.parse_args()

    doc: pymupdf.Document
    with pymupdf.open(args.file) as doc:
        root = tkinter.Tk()
        frm = ttk.Frame(root, padding=10)
        frm.grid()

        label = ttk.Label(frm)
        label.grid(column=1, row=0)

        def load_page(i: int):
            page = doc[i]
            pix = page.get_pixmap()

            mode = "RGBA" if pix.alpha else "RGB"
            img = Image.frombytes(mode, [pix.width, pix.height], pix.samples)
            img = ImageTk.PhotoImage(img)
            label.configure(image=img)
            label.image = img

        def next_page():
            global CURRENT_PAGE
            CURRENT_PAGE += 1
            load_page(CURRENT_PAGE)

        def previous_page():
            global CURRENT_PAGE
            CURRENT_PAGE -= 1
            load_page(CURRENT_PAGE)

        ttk.Button(frm, text="Previous", command=previous_page).grid(column=0, row=0)
        ttk.Button(frm, text="Next", command=next_page).grid(column=2, row=0)

        load_page(CURRENT_PAGE)

        root.mainloop()


if __name__ == "__main__":
    main()