"""
Native Windows file/folder picker, used by the Kivy GUI.

Kivy's built-in FileChooserListView has no address bar, no Quick Access and
awkward keyboard navigation, which makes finding a file on a real PC painful.
This shells out to the standard Windows dialog instead.

It runs in a **separate process** on purpose: Tk wants to own the main event
loop, and Kivy's SDL2 loop is already running in the parent. Isolating Tk in a
child process avoids that conflict entirely, and the result comes back on stdout.

Usage:
    python native_file_dialog.py [--dir START_DIR] [--save] [--folder] [--title T]

Output (one line on stdout):
    SELECTED:<abs path>   on success
    CANCELLED             if the user dismissed the dialog
"""

from __future__ import annotations

import argparse
import os
import sys

IMAGE_TYPES = [
    ("Image files", "*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.tif;*.tiff;*.webp"),
    ("PNG", "*.png"),
    ("JPEG", "*.jpg;*.jpeg"),
    ("Bitmap", "*.bmp"),
    ("All files", "*.*"),
]


def _default_dir(start: str | None) -> str:
    """Pick a sensible starting folder."""
    if start and os.path.isdir(start):
        return start
    if start and os.path.isfile(start):
        return os.path.dirname(start)

    # Prefer the user's Pictures folder, then their home directory.
    home = os.path.expanduser("~")
    pictures = os.path.join(home, "Pictures")
    if os.path.isdir(pictures):
        return pictures
    return home if os.path.isdir(home) else os.getcwd()


def main() -> int:
    parser = argparse.ArgumentParser(description="Native file picker")
    parser.add_argument("--dir", default=None, help="initial directory or file")
    parser.add_argument("--title", default="Select a file")
    parser.add_argument(
        "--folder", action="store_true", help="pick a folder instead of a file"
    )
    parser.add_argument(
        "--save", action="store_true", help="use the save-as dialog"
    )
    args = parser.parse_args()

    try:
        import tkinter
        from tkinter import filedialog
    except ImportError:
        print("ERROR:tkinter is not available in this Python installation", file=sys.stderr)
        return 2

    root = tkinter.Tk()
    root.withdraw()
    # Keep the dialog on top of the Kivy window rather than behind it.
    root.attributes("-topmost", True)
    root.update()

    start = _default_dir(args.dir)
    try:
        if args.folder:
            result = filedialog.askdirectory(
                title=args.title, initialdir=start, mustexist=True
            )
        elif args.save:
            result = filedialog.asksaveasfilename(
                title=args.title,
                initialdir=start,
                defaultextension=".png",
                filetypes=IMAGE_TYPES,
            )
        else:
            result = filedialog.askopenfilename(
                title=args.title, initialdir=start, filetypes=IMAGE_TYPES
            )
    finally:
        try:
            root.destroy()
        except tkinter.TclError:
            pass

    if result:
        print(f"SELECTED:{os.path.normpath(result)}")
    else:
        print("CANCELLED")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())