#!/usr/bin/env python3
# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
from __future__ import absolute_import, division, print_function, unicode_literals

import argparse
import random

import subprocess
import sys
import time


def generate_runtimes(total_runtime):
    # combination of short runtimes and long runtimes, with heavier
    # weight on short runtimes
    possible_runtimes_sec = list(range(1, 10)) + list(range(1, 20)) + [100, 1000]
    runtimes = []
    while total_runtime > 0:
        chosen = random.choice(possible_runtimes_sec)
        chosen = min(chosen, total_runtime)
        runtimes.append(chosen)
        total_runtime -= chosen
    return runtimes


def main(args):
    runtimes = generate_runtimes(int(args.runtime_sec))
    print(
        "Going to execute write stress for " + str(runtimes)
    )  # noqa: E999 T25377293 Grandfathered in
    first_time = True

    for runtime in runtimes:
        kill = random.choice([False, True])

        cmd = "./write_stress --runtime_sec=" + ("-1" if kill else str(runtime))

        if len(args.db) > 0:
            cmd = cmd + " --db=" + args.db

        if first_time:
            first_time = False
        else:
            # use current db
            cmd = cmd + " --destroy_db=false"
        if random.choice([False, True]):
            cmd = cmd + " --delete_obsolete_files_with_fullscan=true"
        if random.choice([False, True]):
            cmd = cmd + " --low_open_files_mode=true"

        print(
            "Running write_stress for %d seconds (%s): %s"
            % (runtime, ("kill-mode" if kill else "clean-shutdown-mode"), cmd)
        )

        child = subprocess.Popen([cmd], shell=True)
        killtime = time.time() + runtime
        while not kill or time.time() < killtime:
            time.sleep(1)
            if child.poll() is not None:
                if child.returncode == 0:
                    break
                else:
                    print(
                        "ERROR: write_stress died with exitcode=%d\n" % child.returncode
                    )
                    sys.exit(1)
        if kill:
            child.kill()
        # breathe
        time.sleep(3)


if __name__ == "__main__":
    random.seed(time.time())
    parser = argparse.ArgumentParser(
        description="This script runs and kills \
        write_stress multiple times"
    )
    parser.add_argument("--runtime_sec", default="1000")
    parser.add_argument("--db", default="")
    args = parser.parse_args()
    main(args)
