#
# Copyright (c) 2022 ZettaScale Technology
#
# This program and the accompanying materials are made available under the
# terms of the Eclipse Public License 2.0 which is available at
# http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
# which is available at https://www.apache.org/licenses/LICENSE-2.0.
#
# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
#
# Contributors:
#   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
#

import itertools
import sys
import time
from datetime import datetime
import argparse
import json
import zenoh
from zenoh import Reliability

# --- Command line argument parsing --- --- --- --- --- ---
parser = argparse.ArgumentParser(
    prog='z_pull',
    description='zenoh pull example')
parser.add_argument('--mode', '-m', dest='mode',
                    choices=['peer', 'client'],
                    type=str,
                    help='The zenoh session mode.')
parser.add_argument('--connect', '-e', dest='connect',
                    metavar='ENDPOINT',
                    action='append',
                    type=str,
                    help='Endpoints to connect to.')
parser.add_argument('--listen', '-l', dest='listen',
                    metavar='ENDPOINT',
                    action='append',
                    type=str,
                    help='Endpoints to listen on.')
parser.add_argument('--key', '-k', dest='key',
                    default='demo/example/**',
                    type=str,
                    help='The key expression matching resources to pull.')
parser.add_argument('--config', '-c', dest='config',
                    metavar='FILE',
                    type=str,
                    help='A configuration file.')

args = parser.parse_args()
conf = zenoh.Config.from_file(
    args.config) if args.config is not None else zenoh.Config()
if args.mode is not None:
    conf.insert_json5(zenoh.config.MODE_KEY, json.dumps(args.mode))
if args.connect is not None:
    conf.insert_json5(zenoh.config.CONNECT_KEY, json.dumps(args.connect))
if args.listen is not None:
    conf.insert_json5(zenoh.config.LISTEN_KEY, json.dumps(args.listen))
key = args.key

# Zenoh code  --- --- --- --- --- --- --- --- --- --- ---


def listen(sample):
    print(f">> [Subscriber] Received {sample.kind} ('{sample.key_expr}': '{sample.payload.decode('utf-8')}')")


def main():
    # initiate logging
    zenoh.init_logger()

    print("Opening session...")
    session = zenoh.open(conf)

    print("Declaring Subscriber on '{}'...".format(key))
    sub = session.declare_pull_subscriber(key, listen, reliability=Reliability.RELIABLE())

    print("Press CTRL-C to quit...")
    for idx in itertools.count():
        time.sleep(1)
        print(f"[{idx:4d}] Pulling...")
        sub.pull()

    sub.undeclare()
    session.close()

main()
