#!/usr/bin/env python3

import asyncio
import random


async def fetch_aio(i):
    await asyncio.sleep(random.randint(1, 5) / 5.0)
    return {'aio_arg': str(i)}


def aio_map(coro, iterable, loop=None):
    if loop is None:
        loop = asyncio.get_event_loop()

    async def wrapped_coro(coro, value):
        return await coro(value)

    coroutines = (wrapped_coro(coro, v) for v in iterable)
    coros = asyncio.gather(*coroutines, return_exceptions=True, loop=loop)

    if not loop.is_running():
        loop.run_until_complete(coros)
    else:  # problem starts here
        # If we run loop.run_until_complete(coros) as well,
        # we get 'RuntimeError: Event loop is running.'
        asyncio.wait(coros)
        # But this way, we get 'asyncio.futures.InvalidStateError: Result is not ready.'
    return coros.result()


def run_aio_map_fron_non_async():
    results = list(aio_map(fetch_aio, range(5)))
    assert(results == [{'aio_arg': '0'}, {'aio_arg': '1'}, {'aio_arg': '2'}, {'aio_arg': '3'}, {'aio_arg': '4'}]), results
    print('Assert ok!')


async def main_loop(loop):
    results = list(aio_map(fetch_aio, range(5)))
    assert(results == [{'aio_arg': '0'}, {'aio_arg': '1'}, {'aio_arg': '2'}, {'aio_arg': '3'}, {'aio_arg': '4'}]), results
    print('Assert ok!')


def run_aio_map_fron_async():
    loop = asyncio.get_event_loop()
    close_after_run = not loop.is_running()

    loop.run_until_complete(main_loop(loop))
    if close_after_run:
        loop.close()

if __name__ == '__main__':
    print('run_aio_map_fron_non_async:')
    run_aio_map_fron_non_async()
    print('run_aio_map_fron_async:')
    run_aio_map_fron_async()
    print('done.')