import argparse
import gym_remote.exceptions as gre
import gym_remote.client as grc
import os
import sys
import traceback
from pkg_resources import EntryPoint


def make(socketdir='tmp/sock'):
    env = grc.RemoteEnv(socketdir)
    return env


def run(agent=None, socketdir='tmp/sock', daemonize=False, args=[]):
    if daemonize:
        pid = os.fork()
        if pid > 0:
            return

    if agent is None:
        print('Running agent: random_agent')
        agent = random_agent
    elif not callable(agent):
        print('Running agent: %s' % agent)
        entrypoint = EntryPoint.parse('entry=' + agent)
        agent = entrypoint.load(False)
    else:
        print('Running agent: %r' % agent)
    env = make(socketdir)
    try:
        agent(env, *args)
    except gre.GymRemoteError:
        pass


def random_agent(env, *args):
    env.reset()
    while True:
        action = env.action_space.sample()
        try:
            ob, reward, done, _ = env.step(action)
        except gre.ResetError:
            done = True
        if done:
            env.reset()


def main(argv=sys.argv[1:]):
    parser = argparse.ArgumentParser(description='Run support code for OpenAI Retro Contest remote environment')
    parser.add_argument('--daemonize', '-d', action='store_true', default=False, help='Daemonize (background) the process')
    parser.add_argument('entry', type=str, nargs='?', help='Entry point to create an agent')
    parser.add_argument('args', nargs='*', help='Optional arguments to the agent')

    args = parser.parse_args(argv)
    run(agent=args.entry, daemonize=args.daemonize, args=args.args)


if __name__ == '__main__':
    main()