#!/bin/env python3

import argparse
import logging
import sys
import signal
import subprocess
import datetime
import os.path
import time
import urllib.request, urllib.parse
from goprocam import GoProCamera, constants

# setup logging facilities
logging.basicConfig(level=logging.INFO)


def setup_cam(dev='gp0'):
    logging.info(f"Connecting to gopro camera at {dev}")
    return GoProCamera.GoPro(ip_address=GoProCamera.GoPro.getWebcamIP(dev),
                             mac_address='0e:7c:80:b5:82:0e',
                             camera=constants.gpcontrol,
                             webcam_device=dev)


def configure_cam(gp,
                  resolution="720p",
                  fps="60",
                  fov="0",
                  autooff=constants.Setup.AutoOff.Never):
    gp.video_settings(resolution, fps)
    gp.gpControlSet(constants.Setup.AUTO_OFF, autooff)


def take_photo(gp, outdir='.'):
    logging.info('Snapping picture!')
    mediauri = gp.take_photo()
    medianame = os.path.basename(urllib.parse.urlparse(mediauri).path)
    outpath = os.path.join(outdir, medianame)
    logging.info(f"Saving to {outpath}")
    urllib.request.urlretrieve(mediauri, filename=outpath)


def webcam(gp,
           resolution=constants.Webcam.Resolution.R720p,
           fov=constants.Webcam.FOV.Wide):
    # prepare v4l2 device
    logging.info('Creating v4l2 device node')
    v4l2p = subprocess.run([
        'doas -n modprobe v4l2loopback && doas -n v4l2loopback-ctl add -n GoPro -x 1 || true'
    ],
                           shell=True,
                           check=True,
                           capture_output=True)
    vnode = v4l2p.stdout.decode('utf-8').strip()

    logging.info(f'Starting webcam mode ({vnode})')
    gp.webcamFOV(fov=fov)
    gp.startWebcam(resolution=resolution)

    try:
        # gracefull handle sigterm
        def sigterm_handler(sig, frame):
            raise SystemExit('SIGTERM')

        signal.signal(signal.SIGTERM, sigterm_handler)
        # pipe video from camera to v4l2 device
        udp_stream = f"udp://{gp.getWebcamIP()}:8554"
        ffmpeg_args = [
            f"ffmpeg -hide_banner -loglevel warning -vsync 2 -fflags nobuffer -flags low_delay -probesize 3072 -nostdin -i {udp_stream} -ar 44100 -f v4l2 -vcodec rawvideo -pix_fmt yuv420p {vnode}"
        ]
        logging.info('Running ffmpeg')
        subprocess.run(ffmpeg_args, shell=True, check=True)
    except (KeyboardInterrupt, SystemExit, Exception):
        # allow camera to shut down
        time.sleep(1)
        # stop webcam mode
        logging.info('Stopping webcam mode')
        gp.stopWebcam()
        subprocess.run([f"doas -n v4l2loopback-ctl del {vnode}"],
                       shell=True,
                       check=True)
        # done
        logging.info('Exiting...')


parser = argparse.ArgumentParser(description='gopro cli utility')
parser.add_argument('-o',
                    '--output-directory',
                    type=str,
                    default=['.'],
                    help='Directory to save files to.')
parser.add_argument('-r',
                    '--resolution',
                    nargs=1,
                    type=str,
                    choices=('1080p', '720p', '420p'),
                    default='1080p',
                    help='Video resolution')
# parser.add_argument('-f',
#                     '--fps',
#                     type=str,
#                     default=['60'],
#                     help='Video frame rate')
parser.add_argument('-v',
                    '--fov',
                    type=str,
                    choices=('wide', 'linear', 'narrow'),
                    default=['wide'],
                    help='Video field of view')

group = parser.add_mutually_exclusive_group()
group.add_argument('--take-photo',
                   action='store_true',
                   help='Take a photo and save it to OUTPUT.')
group.add_argument('--webcam',
                   action='store_true',
                   help='Start webcam mode and register as v4l2 device')

args = parser.parse_args()

res = constants.Webcam.Resolution.R720p
if args.resolution:
    if args.resolution == '1080p':
        res = constants.Webcam.Resolution.R1080p
    elif args.resolution == '720p':
        res = constants.Webcam.Resolution.R720p
    elif args.resolution == '480p':
        res = constants.Webcam.Resolution.R480p

fov = constants.Webcam.FOV.Wide
if args.fov:
    if args.fov == 'wide':
        fov = constants.Webcam.FOV.Wide
    elif args.fov == 'linear':
        fov = constants.Webcam.FOV.Linear
    elif args.fov == 'narrow':
        fov = constants.Webcam.FOV.Narrow

# get camera network device from environment
# should be up and connected (with an ip address assigned)
gp = setup_cam(os.getenv('GOPRO_DEVICE', 'gp0'))
# configure_cam(gp, resolution=args.resolution, fps=args.fps, fov=args.fov)

try:
    if args.take_photo:
        take_photo(gp, outdir=args.output_directory[0])
    if args.webcam:
        webcam(gp, resolution=res, fov=fov)

except Exception as err:
    logging.error(f"error: {err}")
    exit(1)