from time import sleep

from celery import Celery
from celery import group


class Config:
    accept_content = ['pickle', 'json']
    result_serializer = 'pickle'


app = Celery('tasks', backend='redis://localhost', broker='redis://localhost',
             config_source=Config)


@app.task
def add(x, y):
    return x + y


@app.task
def bad_add(x, y):
    raise Exception('Some exception')


def print_result(result):
    print("Result id: {}".format(result.id))
    try:
        msg = result.ready()
    except Exception as e:
        msg = str(e)

    print("Result ready: {}".format(msg))

    print("Parent id: {}".format(result.parent.id))

    try:
        msg = result.parent.ready()
        info = result.parent.info
    except Exception as e:
        msg = str(e)
        info = 'N/A'

    print("Parent ready: {}".format(msg))
    print("Parent info: {}".format(info))

    counter = 1
    for c in result.children:
        print("Child {} id: {}".format(counter, c.id))

        try:
            msg = c.ready()
            info = c.info
        except Exception as e:
            msg = str(e)
            info = 'N/A'

        print("Child {} ready: {}".format(counter, msg))
        print("Child {} info: {}".format(counter, info))
        counter += 1


if __name__ == "__main__":
    print("Everything is ok")
    result = (add.si(1, 2) | group(add.si(3, 4), add.si(5, 6))).delay()
    # delay + sleep instead of get, because get fails saying it needs an argument
    sleep(1)
    print_result(result)
    result.save()

    print("\nOne of the group tasks fail")
    result = (add.si(1, 2) | group(bad_add.si(3, 4), add.si(5, 6))).delay()
    sleep(1)
    print_result(result)
    result.save()

    print("\nThe first task fails")
    result = (bad_add.si(1, 2) | group(add.si(3, 4), add.si(5, 6))).delay()
    sleep(1)
    print_result(result)
    result.save()