import traceback

from collections import namedtuple
from collections.abc import Callable
from tkinter import *
import tkinter.messagebox as messagebox
import tkinter.filedialog as filedialog
from tkinter.ttk import *

from functools import wraps
from pathlib import Path
from platform import system

from PIL import ImageOps 
from PIL.ImagePalette import ImagePalette
from PIL.ImageTk import Image, PhotoImage
from serial import Serial

Resolution = namedtuple("Resolution", ("height", "width"))
IWII_RESOLUTION = Resolution(576, 720)

SUPPORTED_IMAGE_TYPES = sorted("*"+ext for ext, type_ in Image.registered_extensions().items() if type_ in ("PNG", "GIF", "JPEG", "WEBP", "BMP"))

IWII_PALETTE = ImagePalette(
    "P",
    [
        255, 255, 255, #white
        0, 255, 255, #cyan
        255, 0, 255, #magenta
        255, 255, 0, #yellow
        0, 0, 0, #black
    ]
)

def widget_action(func: Callable[[Event], None]) -> Callable[[Event], None]:
    # decorator to wrap widget actions in an error handler that displays exceptions in error message windows
    @wraps(func)
    def wrapper(event: Event):
        try:
            func(event)
        except NotImplementedError as e:
            messagebox.showwarning(
                title="Warning",
                message=f"{func.__name__} not implemented",
                parent=event.widget.master
            )
        except SystemExit:
            # probably unnecessary, but we don't want to accidentally intercept requests to exit
            raise
        except Exception as e:
            messagebox.showerror(
                title="Error",
                message=str(e),
                detail=traceback.format_exc(),
                parent=event.widget.master
            )
            
            quit_photobooth(event)
            exit(1)
    
    return wrapper


@widget_action
def open_preview(event: Event) -> None:
    file = filedialog.askopenfilename(
        parent=event.widget.master,
        title="Open Image",
        initialdir=Path.home(),
        filetypes=[
            ("Supported Image Files", " ".join(SUPPORTED_IMAGE_TYPES))
        ]
    )

    if not file:
        return
    elif Path(file).exists() and Path(file).is_file():
        # load image data and resize to fit the IWII resolution preserving aspect ratio
        image_data = ImageOps.contain(Image.open(file), IWII_RESOLUTION)

        p_img = Image.new('P', image_data.size)
        p_img.putpalette(IWII_PALETTE)

        conv = image_data.quantize(palette=p_img).convert("RGB")

        photo = PhotoImage(conv, size=IWII_RESOLUTION)
        event.widget.create_image(0,0, anchor=CENTER, image=photo)
        # tkinter does not maintain a reference to the local variables of this function upon return
        # without references, the photo and its data get garbage collected and nothing is display
        # therefore we must create references to them to keep them around
        event.widget._displayed_photo=photo
        event.widget.master.photobooth_image = conv

@widget_action
def send_to_printer(event: Event) -> None:
    if not event.widget.master.photobooth_image:
        messagebox.showwarning(
            title="Warning",
            message="Nothing to print. Please take a picture first.",
            parent=event.widget.master
        )
    else:
        with Serial(
            "/dev/ttyUSB0",
            baudrate=9600,
            xonxoff=True,
            rtscts=False
        ) as printer:
            printer.write(event.widget.master.photobooth_image.tobytes())


@widget_action
def clear_preview(event: Event) -> None:
    if event.widget.master.photobooth_image:
        # remove the image data
        event.widget.master.photobooth_image = None
        # clear the canvas
        event.widget.delete("all")
        # remove the reference to the data formerly displayed on the canvas so it gets GC'd
        del event.widget._displayed_photo


@widget_action
def quit_photobooth(event: Event) -> None:
    event.widget.master.destroy()
    event.widget.master.quit()


def photobooth():
    app = Tk()
    app.photobooth_image = None
    app.title("PhotoBooth")

    style = Style()

    match system():
        case "Windows":
            try:
                style.theme_use("winnative")
            except TclError:
                style.theme_use("vista")
        case "Darwin":
            style.theme_use("aqua")
        case "Linux":
            style.theme_use("alt")
            # https://python-forum.io/thread-31235.html
            try:
                # this is so stupid! you have to intentionally do this just to initialize the
                # required namespace to set variables to hide hidden files by default
                app.tk.call("tk_getOpenFile", "-intentionalnonsense")
            except TclError:
                app.setvar("::tk::dialog::file::showHiddenBtn", 1)
                app.setvar("::tk::dialog::file::showHiddenVar", 0)
        case _:
            style.theme_use("default")

    preview = Canvas(master=app, height=IWII_RESOLUTION.height, width=IWII_RESOLUTION.width)
    preview.bind("<space>", open_preview)
    preview.bind("<Return>", send_to_printer)
    preview.bind("c", clear_preview)
    preview.bind("q", quit_photobooth)
    preview.focus_set()
    preview.pack(side="top")
    app.mainloop()

if __name__ == "__main__":
    photobooth()