#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# BITE - A Basic/IoT/Example
# Copyright (C) 2020-2021 Daniele Viganò <daniele@vigano.me>
#
# BITE is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# BITE is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import json
import string
import random
import datetime
import urllib3
import argparse

from time import sleep
import paho.mqtt.publish as publish

DEBUG = bool(os.environ.get("IOT_DEBUG", False))
http = urllib3.PoolManager()


def post_json(endpoint, url, data):
    json_data = json.dumps(data)

    if DEBUG:
        print(json_data)

    encoded_data = json_data.encode("utf8")

    while True:
        try:
            r = http.request(
                "POST",
                endpoint + url,
                body=encoded_data,
                headers={"content-type": "application/json"},
            )
            return r
        except urllib3.exceptions.MaxRetryError:
            pass

        sleep(10)  # retry in 10 seconds


def publish_json(transport, endpoint, data):
    json_data = json.dumps(data)
    serial = data["device"]

    if DEBUG:
        print(json_data)

    encoded_data = json_data.encode("utf8")

    publish.single(
        topic=serial,
        payload=encoded_data,
        hostname=endpoint.split(":")[0],
        port=int(endpoint.split(":")[1]),
        client_id=serial,
        transport=("websockets" if transport == "ws" else "tcp"),
        # auth=auth FIXME
    )


def main():
    parser = argparse.ArgumentParser(description="IoT simulator oprions")

    parser.add_argument(
        "-e",
        "--endpoint",
        default=os.environ.get("IOT_HTTP", "http://127.0.0.1:8000"),
        help="IoT HTTP endpoint",
    )
    parser.add_argument(
        "-m",
        "--mqtt",
        default=os.environ.get("IOT_MQTT", "127.0.0.1:1883"),
        help="IoT MQTT endpoint",
    )
    parser.add_argument(
        "-t",
        "--transport",
        choices=["mqtt", "ws", "http"],
        default=os.environ.get("IOT_TL", "http"),
        help="IoT transport layer",
    )
    parser.add_argument(
        "-s",
        "--serial",
        default=os.environ.get("IOT_SERIAL"),
        help="IoT device serial number",
    )
    parser.add_argument(
        "-d",
        "--delay",
        metavar="s",
        type=float,
        default=os.environ.get("IOT_DELAY", 10),
        help="Delay between requests",
    )
    args = parser.parse_args()

    subscribe = "/api/device/subscribe/"
    telemetry = "/telemetry/"

    if args.serial is None:
        args.serial = "".join(
            random.choices(string.ascii_lowercase + string.digits, k=8)
        )

    data = {"serial": args.serial}
    post_json(args.endpoint, subscribe, data)

    while True:
        data = {
            "device": args.serial,
            "clock": int(datetime.datetime.now().timestamp()),
        }
        payload = {
            "id": "device_simulator",
            "light": random.randint(300, 500),
            "temperature": {"celsius": round(random.uniform(20, 28), 1)},
        }
        if args.transport == "http":
            post_json(args.endpoint, telemetry, {**data, "payload": payload})
        elif args.transport in ("mqtt", "ws"):
            publish_json(
                args.transport, args.mqtt, {**data, "payload": payload}
            )
        else:
            raise NotImplementedError
        sleep(args.delay)


if __name__ == "__main__":
    main()