#!/usr/bin/env python3
import argparse
import configparser
import logging
import os
import sys
import time

sys.path.append(os.path.join(os.path.dirname(__file__), ".."))
from scripts.lib.setup_path import setup_path

setup_path()

import requests
from requests.adapters import HTTPAdapter
from urllib3.util import Retry

from scripts.lib.zulip_tools import get_config, get_config_file, get_tornado_ports

config_file = get_config_file()
reload_rate = int(
    get_config(
        config_file,
        "application_server",
        "client_reload_rate",
        "50",
    )
)

parser = argparse.ArgumentParser()
parser.add_argument(
    "--rate", type=int, help="Number of clients to reload per second", default=reload_rate
)

args = parser.parse_args()
reload_rate = args.rate

secret_config_file = configparser.RawConfigParser()
secret_config_file.read("/etc/zulip/zulip-secrets.conf")
shared_secret = get_config(secret_config_file, "secrets", "shared_secret")
assert shared_secret

# Perform relatively slow retries (2s, 4s, 8s) with backoff, including
# on POST requests.  Failure to send this request successfully means
# that clients may fail to reload, so we want to be somewhat resilient
# to failures.  Since we are on localhost, we do not expect network
# failures, only Tornado restarts, to cause failures here.
retry = Retry(total=3, backoff_factor=1, allowed_methods=Retry.DEFAULT_ALLOWED_METHODS | {"POST"})
c = requests.Session()
c.mount("http://", HTTPAdapter(max_retries=retry))

logging.Formatter.converter = time.gmtime
logging.basicConfig(format="%(asctime)s reload-clients: %(message)s", level=logging.INFO)

first = True
server_total = 0
for port in get_tornado_ports(config_file):
    logging.info("Starting to send client reload events to Tornado port %d", port)
    try:
        shard_total = 0
        complete = False
        # Rather than make a sustained one request per second, we batch
        # into 5-second chunks of 5 times the client_reload_rate
        SECONDS_PER_BATCH = 5
        while not complete:
            if not first:
                time.sleep(SECONDS_PER_BATCH)
            first = False

            logging.info("Sending reload events to %d clients", reload_rate * SECONDS_PER_BATCH)
            resp = c.post(
                f"http://127.0.0.1:{port}/api/internal/web_reload_clients",
                data={"client_count": reload_rate * SECONDS_PER_BATCH, "secret": shared_secret},
                timeout=5,
            )
            resp.raise_for_status()
            shard_total += resp.json()["sent_events"]
            complete = resp.json()["complete"]
        logging.info("Sent %d reload events to Tornado port %d", shard_total, port)
        server_total += shard_total
    except requests.exceptions.HTTPError:
        # Failures in one shard likely won't affect other shards --
        # give up on this shard, and try the next one,
        logging.exception("Failed to send web_reload_clients request to Tornado port %d", port)

if len(get_tornado_ports(config_file)) > 1:
    logging.info("Sent total of %d reload events, across all Tornado instances", server_total)