# srec: A simple GUI for screen recording
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation, version 3.

from dataclasses import dataclass
from datetime import datetime
import os
import subprocess
from typing import Callable

import gi
gi.require_version("Gtk", "4.0")
from gi.repository import Gtk  # nopep8 pylint: disable=wrong-import-position


@dataclass
class Recording:
    filename: str
    process: subprocess.Popen[bytes]


recording: Recording | None = None


def make_filename() -> str:
    directory = os.environ.get(
        'XDG_VIDEOS_DIR',
        os.path.expanduser('~/Videos'))
    os.makedirs(directory, exist_ok=True)
    timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    return os.path.join(directory, f'srec {timestamp}.mkv')


def video_source(stack: Gtk.Stack) -> list[str]:
    if stack.get_child_by_name('not_recording').get_first_child().get_active():
        return ['-f', 'v4l2', '-i', '/dev/video0']
    return ['-f', 'x11grab', '-i', ':0.0+0,0']


def on_start_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:
    global recording  # pylint: disable=global-statement
    assert recording is None
    filename = make_filename()
    command = (['ffmpeg', '-framerate', '25'] + video_source(stack) +
               ['-f', 'pulse', '-ac', '2', '-i', 'default', filename])
    # pylint: disable=consider-using-with
    recording = Recording(
        filename=filename,
        process=subprocess.Popen(command, stdin=subprocess.PIPE))
    stack.set_visible_child_name("recording")


def on_stop_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:
    global recording  # pylint: disable=global-statement
    assert recording is not None
    stdin = recording.process.stdin
    assert stdin is not None
    stdin.write(b'q')
    stdin.flush()
    recording.process.wait()
    recording = None
    stack.set_visible_child_name("not_recording")


def make_button(label: str, action: Callable[[
                Gtk.Button, Gtk.Stack], None], stack: Gtk.Stack) -> Gtk.Button:
    button = Gtk.Button(label=label)
    button.connect('clicked', action, stack)
    button.set_margin_top(10)
    button.set_margin_start(10)
    button.set_margin_end(10)
    button.set_margin_bottom(10)
    return button


def on_activate(app: Gtk.Application) -> None:
    win = Gtk.ApplicationWindow(application=app)
    win.set_title('SRec')
    stack = Gtk.Stack()

    nr_box = Gtk.Box()
    nr_box.set_orientation(Gtk.Orientation.VERTICAL)
    webcam = Gtk.CheckButton(label='Webcam', active=True)
    nr_box.append(webcam)
    nr_box.append(Gtk.CheckButton(label='Screen', group=webcam))
    nr_box.append(make_button("Start Recording", on_start_recording, stack))
    stack.add_named(nr_box, "not_recording")

    r_box = Gtk.Box()
    r_box.set_orientation(Gtk.Orientation.VERTICAL)
    r_box.append(make_button("Stop Recording", on_stop_recording, stack))
    stack.add_named(r_box, "recording")

    win.set_child(stack)
    win.present()


def main() -> None:
    app = Gtk.Application(application_id='net.chkno.srec')
    app.connect('activate', on_activate)
    app.run(None)


if __name__ == '__main__':
    main()