#!/usr/bin/env python3
#
# An easy Trello integration for Zulip.


import argparse
import sys

try:
    import requests
except ImportError:
    print("Error: Please install the python requests library before running this script:")
    print("http://docs.python-requests.org/en/master/user/install/")
    sys.exit(1)


def get_model_id(options):
    """get_model_id

    Get Model Id from Trello API

    :options: argparse.Namespace arguments

    :returns: str id_model Trello board idModel

    """

    trello_api_url = 'https://api.trello.com/1/board/{}'.format(options.trello_board_id)

    params = {
        'key': options.trello_api_key,
        'token': options.trello_token,
    }

    trello_response = requests.get(trello_api_url, params=params)

    if trello_response.status_code != 200:
        print('Error: Can\'t get the idModel. Please check the configuration')
        sys.exit(1)

    board_info_json = trello_response.json()

    return board_info_json['id']


def get_webhook_id(options, id_model):
    """get_webhook_id

    Get webhook id from Trello API

    :options: argparse.Namespace arguments
    :id_model: str Trello board idModel

    :returns: str id_webhook Trello webhook id

    """

    trello_api_url = 'https://api.trello.com/1/webhooks/'

    data = {
        'key': options.trello_api_key,
        'token': options.trello_token,
        'description': 'Webhook for Zulip integration (From Trello {} to Zulip)'.format(
            options.trello_board_name,
        ),
        'callbackURL': options.zulip_webhook_url,
        'idModel': id_model,
    }

    trello_response = requests.post(trello_api_url, data=data)

    if trello_response.status_code != 200:
        print('Error: Can\'t create the Webhook:', trello_response.text)
        sys.exit(1)

    webhook_info_json = trello_response.json()

    return webhook_info_json['id']


def create_webhook(options):
    """create_webhook

    Create Trello webhook

    :options: argparse.Namespace arguments

    """

    # first, we need to get the idModel
    print('Getting Trello idModel for the {} board...'.format(options.trello_board_name))

    id_model = get_model_id(options)

    if id_model:
        print('Success! The idModel is', id_model)

    id_webhook = get_webhook_id(options, id_model)

    if id_webhook:
        print('Success! The webhook ID is', id_webhook)

    print(
        'Success! The webhook for the {} Trello board was successfully created.'.format(
            options.trello_board_name
        )
    )


def main():
    description = """
zulip_trello.py is a handy little script that allows Zulip users to
quickly set up a Trello webhook.

Note: The Trello webhook instructions available on your Zulip server
may be outdated. Please make sure you follow the updated instructions
at <https://zulip.com/integrations/doc/trello>.
"""

    parser = argparse.ArgumentParser(description=description)
    parser.add_argument('--trello-board-name', required=True, help='The Trello board name.')
    parser.add_argument(
        '--trello-board-id',
        required=True,
        help=('The Trello board short ID. Can usually be found ' 'in the URL of the Trello board.'),
    )
    parser.add_argument(
        '--trello-api-key',
        required=True,
        help=(
            'Visit https://trello.com/1/appkey/generate to generate '
            'an APPLICATION_KEY (need to be logged into Trello).'
        ),
    )
    parser.add_argument(
        '--trello-token',
        required=True,
        help=(
            'Visit https://trello.com/1/appkey/generate and under '
            '`Developer API Keys`, click on `Token` and generate '
            'a Trello access token.'
        ),
    )
    parser.add_argument(
        '--zulip-webhook-url', required=True, help='The webhook URL that Trello will query.'
    )

    options = parser.parse_args()
    create_webhook(options)


if __name__ == '__main__':
    main()