main.py

import json
import random
from paho.mqtt.client import *
from dotenv import load_dotenv
from src.gps.GPSDataReader import read_satellite_data
import os
import ssl

UPDATE_INTERVAL = 60
satellites = {}


def update_position(msg):
    current_prns = set()

    for sat in msg.get("satellites", []):
        prn = sat.get("PRN")
        if prn is None:
            continue

        current_prns.add(prn)

        azimuth = sat.get("az", random.uniform(0, 360))
        elevation = max(0, min(90, sat.get("el", random.uniform(0, 10))))

        if prn in satellites:
            satellites[prn]["azimuth"] = azimuth % 360
            satellites[prn]["elevation"] = elevation
            satellites[prn]["signal"] = sat.get("ss", 0)
            satellites[prn]["used"] = sat.get("used", False)
            satellites[prn]["fading"] = False
        else:
            satellites[prn] = {
                "id": prn,
                "azimuth": azimuth % 360,
                "elevation": elevation,
                "signal": sat.get("ss", 0),
                "used": sat.get("used", False),
                "fading": False,
            }

    for prn in list(satellites.keys()):
        if prn not in current_prns:
            satellites[prn]["fading"] = True


def simulate_movement():
    to_remove = []

    for prn, sat in satellites.items():
        if sat["fading"]:
            sat["elevation"] -= 2
            if sat["elevation"] <= 0:
                to_remove.append(prn)
        else:
            sat["azimuth"] = (sat["azimuth"] + random.uniform(-3, 3)) % 360
            sat["elevation"] = max(0, min(90, sat["elevation"] + random.uniform(-1, 1)))

    for prn in to_remove:
        del satellites[prn]


def get_public_payload():
    return {
        "visibleCount": len(satellites),
        "usedCount": sum(1 for sat in satellites.values() if sat.get("used", False)),
        "hdop": round(random.uniform(0.8, 2.5), 2),
        "satellites": list(satellites.values()),
    }


def main():
    last_update = time.time()
    print("Starting simulation...")
    load_dotenv()

    user = os.getenv("MQTT_USER")
    password = os.getenv("MQTT_PASSWORD")
    host = os.getenv("MQTT_HOST")
    port = os.getenv("MQTT_PORT", "8883")

    if not host:
        raise ValueError("MQTT_HOST is required")

    client = Client(client_id="", userdata=None, protocol=MQTTv5)
    client.tls_set(tls_version=ssl.PROTOCOL_TLS_CLIENT)
    client.username_pw_set(user, password)
    client.connect(host, int(port))
    client.loop_start()

    try:
        for msg in read_satellite_data():
            if msg is None:
                continue

            update_position(msg)

            now = time.time()
            if now - last_update >= UPDATE_INTERVAL:
                simulate_movement()
                payload = get_public_payload()
                client.publish("gps/satellites", json.dumps(payload))

                last_update = now
    except KeyboardInterrupt:
        print("Stopped by user.")
        client.loop_stop()
        client.disconnect()



if __name__ == "__main__":
    main()