"""Logic for executing functions in parallel using flask-executor.

Basically it's a ThreadPoolExecutor, but with g object available.
"""

import concurrent.futures

from analytics.api import executor


def execute_in_parallel(requests):
    """Execute requests in parallel.

    Provided a dict of requests, execute them with the provided id and kwargs.
    Return the results of these requests in a dict keyed by keys in the
    requests parameter.
    """
    futures = {
        executor.submit(
            request['func'],
            *request['args'],
            **request['kwargs']
        ): key for (key, request) in requests.items()
    }
    concurrent.futures.wait(futures)
    output = dict(map(lambda f: (futures[f], f.result()), futures))

    return output