from __future__ import annotations

from typing import Iterable

import gi

gi.require_version("Gtk", "3.0")
gi.require_version("Gdk", "3.0")

from gi.repository import Gdk, Gtk
from Xlib import X, XK, display
from Xlib.ext import xtest


def write_clipboard(text: str) -> None:
    Gtk.init([])
    clipboard = Gtk.Clipboard.get(Gdk.SELECTION_CLIPBOARD)
    clipboard.set_text(text, -1)
    clipboard.store()
    while Gtk.events_pending():
        Gtk.main_iteration()


def paste_clipboard() -> None:
    dpy = display.Display()
    _send_combo(dpy, ["Control_L", "Shift_L", "v"])


def type_text(text: str) -> None:
    if not text:
        return
    dpy = display.Display()
    for ch in text:
        if ch == "\n":
            _send_combo(dpy, ["Return"])
            continue
        keysym, needs_shift = _keysym_for_char(ch)
        if keysym is None:
            continue
        if needs_shift:
            _send_combo(dpy, ["Shift_L", keysym], already_keysym=True)
        else:
            _send_combo(dpy, [keysym], already_keysym=True)


def inject(text: str, backend: str) -> None:
    backend = (backend or "").strip().lower()
    if backend in ("", "clipboard"):
        write_clipboard(text)
        paste_clipboard()
        return
    if backend == "injection":
        type_text(text)
        return
    raise ValueError(f"unknown injection backend: {backend}")


def _send_combo(dpy: display.Display, keys: Iterable[str], already_keysym: bool = False) -> None:
    keycodes: list[int] = []
    for key in keys:
        keysym = key if already_keysym else XK.string_to_keysym(key)
        if keysym == 0:
            continue
        keycode = dpy.keysym_to_keycode(keysym)
        if keycode == 0:
            continue
        keycodes.append(keycode)
    for code in keycodes:
        xtest.fake_input(dpy, X.KeyPress, code)
    for code in reversed(keycodes):
        xtest.fake_input(dpy, X.KeyRelease, code)
    dpy.flush()


_SHIFTED = {
    "!": "1",
    "@": "2",
    "#": "3",
    "$": "4",
    "%": "5",
    "^": "6",
    "&": "7",
    "*": "8",
    "(": "9",
    ")": "0",
    "_": "-",
    "+": "=",
    "{": "[",
    "}": "]",
    "|": "\\",
    ":": ";",
    "\"": "'",
    "<": ",",
    ">": ".",
    "?": "/",
}


def _keysym_for_char(ch: str) -> tuple[int | None, bool]:
    if ch.isupper():
        base = ch.lower()
        keysym = XK.string_to_keysym(base)
        return (keysym if keysym != 0 else None, True)
    if ch in _SHIFTED:
        keysym = XK.string_to_keysym(_SHIFTED[ch])
        return (keysym if keysym != 0 else None, True)
    if ch == " ":
        return (XK.string_to_keysym("space"), False)
    keysym = XK.string_to_keysym(ch)
    return (keysym if keysym != 0 else None, False)