#!/usr/bin/env python3
"""Drive the desktop build from outside, for the manual's screenshots.

    drive.py launch [args...]   start the app on the private X server
    drive.py stop
    drive.py shot OUT.png
    drive.py click X Y [button]
    drive.py move X Y
    drive.py drag X1 Y1 X2 Y2 [steps]
    drive.py type TEXT
    drive.py key KEYSYM...
    drive.py rec OUT.mp4 / cut  start and stop a recording of the window
    drive.py where              the pointer, in window coordinates

Everything is in *window* pixels, at scale 1, with the window at the origin
of a 1920×1200 Xvfb on `DR_DISPLAY` (`:7`). The app gets its own XDG
profile under `DR_HOME` (`/var/tmp/dr-manual`), so nothing here touches the
library or settings of whoever is logged in; `DR_BIN` names the binary.

Two things that cost an afternoon, kept here so they cost nobody else one:
a Slint `TouchArea` wants a *held* press (`mousedown`, a beat, `mouseup`) —
xdotool's `click` is sometimes dropped; and under XWayland at scale 2 a
pointer warp lands at twice the coordinate asked for, which is why this runs
on Xvfb rather than the desktop.
"""
import os
import subprocess
import sys
import time

HOME = os.environ.get('DR_HOME', '/var/tmp/dr-manual')
DISPLAY = os.environ.get('DR_DISPLAY', ':7')
BIN = os.environ.get('DR_BIN', 'target/release/darkroom-desktop')
ENV = dict(
    os.environ,
    XDG_CONFIG_HOME=f'{HOME}/xdg/config',
    XDG_DATA_HOME=f'{HOME}/xdg/data',
    XDG_STATE_HOME=f'{HOME}/xdg/state',
    RUST_LOG='info',
    WINIT_X11_SCALE_FACTOR='1',
    DISPLAY=DISPLAY,
)
ENV.pop('WAYLAND_DISPLAY', None)
os.environ['DISPLAY'] = DISPLAY


def x(*args, check=True):
    return subprocess.run(
        ['xdotool', *map(str, args)], capture_output=True, text=True, check=check
    ).stdout.strip()


def win():
    return open(f'{HOME}/app.win').read().strip()


def geometry():
    out = x('getwindowgeometry', win())
    pos = out.split('Position: ')[1].split(' ')[0]
    px, py = map(int, pos.split(','))
    return px, py


def launch(args):
    os.makedirs(HOME, exist_ok=True)
    log = open(f'{HOME}/app.log', 'w')
    p = subprocess.Popen([BIN, *args], env=ENV, stdout=log, stderr=subprocess.STDOUT)
    open(f'{HOME}/app.pid', 'w').write(str(p.pid))
    w = ''
    for _ in range(120):
        w = x('search', '--pid', p.pid, '--name', 'DarkRoom', check=False).split('\n')[-1]
        if w:
            break
        time.sleep(0.5)
    time.sleep(1.5)
    W, H = os.environ.get('WIDTH', '1600'), os.environ.get('HEIGHT', '1100')
    x('windowsize', '--sync', w, W, H)
    time.sleep(0.5)
    x('windowmove', '--sync', w, 0, 0)
    x('windowfocus', '--sync', w, check=False)
    open(f'{HOME}/app.win', 'w').write(w)
    print(f'pid {p.pid} win {w}')


def stop():
    try:
        os.kill(int(open(f'{HOME}/app.pid').read()), 15)
    except (OSError, ValueError) as e:
        print(e)
    time.sleep(1)


def shot(out):
    subprocess.run(['import', '-window', win(), out], check=True)


def move(px, py):
    ox, oy = geometry()
    x('mousemove', '--sync', ox + int(px), oy + int(py))


def click(px, py, button=1):
    x('windowfocus', '--sync', win(), check=False)
    move(px, py)
    time.sleep(0.15)
    x('mousedown', button)
    time.sleep(0.12)
    x('mouseup', button)


def drag(x1, y1, x2, y2, steps=20):
    x('windowfocus', '--sync', win(), check=False)
    move(x1, y1)
    time.sleep(0.15)
    x('mousedown', 1)
    time.sleep(0.15)
    for i in range(1, int(steps) + 1):
        t = i / int(steps)
        move(int(x1) + (int(x2) - int(x1)) * t, int(y1) + (int(y2) - int(y1)) * t)
        time.sleep(0.03)
    time.sleep(0.15)
    x('mouseup', 1)


def drag_path(points, steps=20):
    """A drag through several points: out of the grid sideways first, then
    to the row. A diagonal with much vertical in it is taken by the grid's
    Flickable as a scroll before the DragArea can claim it."""
    x('windowfocus', '--sync', win(), check=False)
    (x1, y1), rest = points[0], points[1:]
    move(x1, y1)
    time.sleep(0.15)
    x('mousedown', 1)
    time.sleep(0.15)
    for x2, y2 in rest:
        for i in range(1, int(steps) + 1):
            t = i / int(steps)
            move(int(x1 + (x2 - x1) * t), int(y1 + (y2 - y1) * t))
            time.sleep(0.03)
        x1, y1 = x2, y2
    time.sleep(0.4)
    x('mouseup', 1)


def rec_start(out):
    size = x('getwindowgeometry', win()).split('Geometry: ')[1].strip()
    ox, oy = geometry()
    p = subprocess.Popen([
        'ffmpeg', '-hide_banner', '-loglevel', 'error', '-f', 'x11grab',
        '-framerate', '15', '-video_size', size, '-i', f'{DISPLAY}+{ox},{oy}',
        '-c:v', 'libx264', '-preset', 'ultrafast', '-qp', '0', '-y', out,
    ])
    open(f'{HOME}/rec.pid', 'w').write(str(p.pid))
    time.sleep(0.5)


def rec_stop():
    pid = int(open(f'{HOME}/rec.pid').read())
    os.kill(pid, 2)
    for _ in range(50):
        try:
            os.kill(pid, 0)
            time.sleep(0.1)
        except OSError:
            break


def where():
    out = x('getmouselocation')
    mx, my = [int(v.split(':')[1]) for v in out.split()[:2]]
    ox, oy = geometry()
    print(mx - ox, my - oy)


if __name__ == '__main__':
    cmd, *a = sys.argv[1:]
    if cmd == 'launch':
        launch(a)
    elif cmd == 'stop':
        stop()
    elif cmd == 'shot':
        shot(a[0])
    elif cmd == 'click':
        click(*a)
    elif cmd == 'move':
        move(*a)
    elif cmd == 'drag':
        drag(*a)
    elif cmd == 'type':
        x('windowfocus', '--sync', win(), check=False)
        x('type', '--delay', '120', a[0])
    elif cmd == 'key':
        x('windowfocus', '--sync', win(), check=False)
        x('key', '--delay', '80', *a)
    elif cmd == 'rec':
        rec_start(a[0])
    elif cmd == 'cut':
        rec_stop()
    elif cmd == 'where':
        where()
    else:
        sys.exit(__doc__)