from typing import Optional
import time
import pycurl
import itertools
import argparse
import multiprocessing
import paho.mqtt.client
from datetime import datetime
from blist import blist
from dataclasses import dataclass
import threading
import queue
import sys
import csv
import random
import textwrap


@dataclass(frozen=False, init=True)
class UploadRequest:
    id: int
    upload_started: float = None
    upload_finished: float = None
    upload_status_code: bool = False
    alert_arrived: float = None


@dataclass(frozen=False, init=True)
class ReturnedRequest:
    id: int
    arrived: float


def independent_worker(result_queue, filename: str, timeout: float, target_url: str):
    prepared_curl = pycurl.Curl()
    prepared_curl.setopt(pycurl.URL, target_url)
    prepared_curl.setopt(pycurl.SSL_VERIFYPEER, 0)
    prepared_curl.setopt(pycurl.SSL_VERIFYHOST, 0)
    # prepared_curl.setopt(pycurl.FORBID_REUSE, 0)
    prepared_curl.setopt(pycurl.HTTP_VERSION, pycurl.CURL_HTTP_VERSION_2_0)
    prepared_curl.setopt(pycurl.WRITEFUNCTION, lambda _: None)

    completed_jobs_list = blist()  # O(log n) insert instead of python's O(n)

    worker_stop_time = 0
    worker_completed_job_count = 0

    # Start working!!
    worker_start_time = time.time()
    while True:
        jobid = random.randint(0, 2147483647)
        prepared_curl.setopt(pycurl.HTTPPOST, [
            ('file', (
                pycurl.FORM_FILE, filename  # Copying buffers from Python memory would be even slower... trust me
            )),
            ('description', (
                pycurl.FORM_BUFFERPTR, f'{{"date": "{datetime.now().isoformat()}", "device_id" : "{jobid}"}}',
                pycurl.FORM_CONTENTTYPE, 'application/json',
            ))
        ])

        job_start_time = time.time()
        prepared_curl.perform()
        job_stop_time = time.time()
        status_code = prepared_curl.getinfo(pycurl.HTTP_CODE)

        worker_completed_job_count += 1

        completed_jobs_list.append(UploadRequest(
            id=jobid,
            upload_started=job_start_time,
            upload_finished=job_stop_time,
            upload_status_code=status_code
        ))

        if (job_stop_time - worker_start_time) >= timeout:
            worker_stop_time = job_stop_time
            break

    # end of loop
    runtime = worker_stop_time - worker_start_time
    prepared_curl.close()

    result_queue.put(
        (runtime, worker_completed_job_count, completed_jobs_list)
    )


def mqtt_on_connect(client, userdata, flags, rc):
    client.subscribe(f"command/#")


def mqtt_on_command(client, userdata, message):
    # msg = json.loads(message.payload.decode())
    # if msg['command'] == 'doAlert':
    _id = int(message.topic[8:])  # len('command/') = 8
    userdata.put(ReturnedRequest(id=_id, arrived=time.time()))


def mqtt_on_subscribe(client, userdata, mid, granted_qos):
    userdata.set()


def run_benchmark(num_workers: int, timeout: float, filename: str, target_url: str):
    result_queue = multiprocessing.Queue()

    workers = []
    for _ in range(num_workers):
        workers.append(multiprocessing.Process(
            target=independent_worker,
            args=(result_queue, filename, timeout, target_url)
        ))

    for w in workers:
        w.start()

    completed_workers = 0
    all_requests_completed = {}
    count_requests_completed = 0
    while completed_workers < num_workers:
        results = result_queue.get()
        count_requests_completed += results[1]
        for result in results[2]:
            all_requests_completed[result.id] = result

        completed_workers += 1

    for w in workers:
        w.join()

    assert count_requests_completed == len(all_requests_completed)

    final_sorted_results = list(all_requests_completed.values())
    final_sorted_results.sort(key=lambda a: a.upload_started)  # sort by upload start time

    return final_sorted_results


def csv_time_format(timestamp: Optional[float]) -> Optional[str]:
    if timestamp:
        return datetime.fromtimestamp(timestamp).isoformat()
    else:
        return None


def write_results(results, file_handle):
    writer = csv.writer(file_handle)
    # Latency and rtt are in ms

    writer.writerow(
        ['id', 'http_start_time', 'http_complete_time', 'http_time', 'status_code', 'mqtt_arrive_time', 'latency',
         'rtt']
    )

    for result in results:
        http_time = (result.upload_finished - result.upload_started) * 1000 if result.upload_finished else None
        latency = (result.alert_arrived - result.upload_finished) * 1000 if result.alert_arrived else None
        rtt = (result.alert_arrived - result.upload_started) * 1000 if result.alert_arrived else None

        row = [
            result.id,
            csv_time_format(result.upload_started),
            csv_time_format(result.upload_finished),
            http_time,
            result.upload_status_code,
            csv_time_format(result.alert_arrived),
            latency,
            rtt
        ]
        writer.writerow(row)


def main():
    help_epilog = textwrap.dedent('''\
    CSV Columns meaning:
        id - Unique ID of a request (not sequential but at least unique)
        http_start_time - Timestamp of when the HTTP request is started
        http_complete_time - Timestamp of when the HTTP request is completed
        http_time - Time it took to perform the HTTP request (i.e. Uploading) in milliseconds
        status_code - Status code of the HTTP request
        mqtt_arrive_time - Timestamp of when the corresponding MQTT message arrived
        latency - Latency of the system (http_complete_time - mqtt_arrive_time) in milliseconds
        rtt - Total round trip time (http_start_time - mqtt_arrive_time) in milliseconds
    ''')

    parser = argparse.ArgumentParser(
        description='Birbnetes Benchmarker 3',
        epilog=help_epilog,
        formatter_class=argparse.RawTextHelpFormatter
    )
    parser.add_argument('--workers', type=int, required=False, default=1, help='Number of workers (or threads)')
    parser.add_argument('--timeout', type=int, required=False, default=10,
                        help='Maximum time for request sending (0 for unlimited)')

    parser.add_argument('--file', type=str, required=True, help='Name of the sound file to upload')
    parser.add_argument('--target-url', type=str, required=False, default="https://birb.k8s.kmlabz.com/benchmark",
                        help='The target endpoint')

    parser.add_argument('--inflight-timeout', type=int, required=False, default=30,
                        help='Number of seconds to wait for MQTT messages to arrive after uploading finished (not very precise) (0 for not waiting)')

    parser.add_argument('--output', type=str, required=True, help='name of the file to write results to (- for stdout)')

    parser.add_argument('--mqtt-username', type=str, required=False, default="birbnetes",
                        help="Username for the MQTT server")
    parser.add_argument('--mqtt-port', type=int, required=False, default=1883, help="Port for the MQTT server")
    parser.add_argument('--mqtt-host', type=str, required=False, default="mqtt.kmlabz.com",
                        help="Hostname for the MQTT server")
    parser.add_argument('--mqtt-password', type=str, required=False, default=None, help="Username for the MQTT server")

    args = parser.parse_args()

    print("Workers:", args.workers)
    print("Timeout:", args.timeout, "sec")

    alerts_arrived_queue = queue.Queue()

    print(f"Preparing MQTT (host: {args.mqtt_host}:{args.mqtt_port}, login: {bool(args.mqtt_password)})")
    subscription_waiter = threading.Event()
    # Preparing connection
    mqtt_client = paho.mqtt.client.Client(client_id="10")
    mqtt_client.on_connect = mqtt_on_connect
    mqtt_client.on_subscribe = mqtt_on_subscribe
    mqtt_client.user_data_set(subscription_waiter)
    if args.mqtt_password:
        mqtt_client.username_pw_set(args.mqtt_username, args.mqtt_password)
    # this is a blocking call, will wait until connecion is complete
    mqtt_client.connect(args.mqtt_host, args.mqtt_port, 60)
    # Start loop in background
    mqtt_client.loop_start()
    # Wait for subscription to be made
    subscription_waiter.wait()
    # Set final command reciever
    mqtt_client.user_data_set(alerts_arrived_queue)
    mqtt_client.on_message = mqtt_on_command
    print("MQTT Complete!")

    print("Running benchmark...")
    benchmark_results = run_benchmark(args.workers, args.timeout, args.file, args.target_url)

    # Wait for inflight messages for a little
    total_successful_uploads = len([req for req in benchmark_results if req.upload_status_code == 200])
    all_arrived = alerts_arrived_queue.qsize() >= total_successful_uploads

    if (not all_arrived) and (args.inflight_timeout > 0):
        print("Waiting for inflight MQTT messages to arrive...")

        waiting_started = time.time()
        for _ in range(int(args.inflight_timeout * 1000)):
            if alerts_arrived_queue.qsize() >= total_successful_uploads:
                all_arrived = True
                break

            time.sleep(0.001)
        waited_for_inflight = time.time() - waiting_started
        print(f"Waited a total {waited_for_inflight} seconds")

    if not all_arrived:
        print("WARNING: Not all MQTT Messages arrived!")

    # Disconnectiong MQTT
    mqtt_client.disconnect()
    mqtt_client.loop_stop()  # This stops further recieving MQTT messages

    # Aggregate results
    total_answered = 0
    while True:
        try:
            returned_job = alerts_arrived_queue.get_nowait()
        except queue.Empty:
            break

        # super ghetto pairing
        paired = False
        for benchmark_result in benchmark_results:
            if benchmark_result.id == returned_job.id:
                benchmark_result.alert_arrived = returned_job.arrived
                paired = True
                break

        if not paired:
            print("Bruh moment: Alert arrived with an id that's not sent", returned_job.id)

        total_answered += 1

    # print some mini statistics
    total_runtime = max(benchmark_results, key=lambda a: a.upload_finished).upload_finished - \
                    min(benchmark_results, key=lambda a: a.upload_started).upload_started

    print(
        f"{len(benchmark_results)} requests completed: {total_successful_uploads} successfully uploaded and {total_answered} answered"
    )
    print(f"Test total runtime was {total_runtime} seconds")
    print("HTTP Request/sec:", len(benchmark_results) / total_runtime)

    if args.output == '-':
        print("Writing results to STDOUT")
        print("\n---------- CUT HERE ----------\n")
        write_results(benchmark_results, sys.stdout)
    else:
        print("Writing results to", args.output)
        with open(args.output, 'w') as f:
            write_results(benchmark_results, f)


if __name__ == '__main__':
    main()