# examples/meshcore_simulator.py
"""
Simple Meshcore Serial Device Simulator.
"""

import serial
import time
import json
import threading
import random

SIMULATOR_PORT = "/dev/ttyS1"
BAUD_RATE = 9600
SEND_PERIODIC_SENSOR_DATA = True
SENSOR_INTERVAL_S = 15

shutdown_event = threading.Event()
serial_port = None

def serial_reader():
    print("[Reader] Serial reader thread started.")
    while not shutdown_event.is_set():
        if serial_port and serial_port.is_open:
            try:
                if serial_port.in_waiting > 0:
                    line = serial_port.readline()
                    if line:
                        try:
                            decoded_line = line.decode('utf-8').strip()
                            print(f"\n[Reader] <<< Received: {decoded_line}")
                        except UnicodeDecodeError:
                            print(f"\n[Reader] <<< Received non-UTF8 data: {line!r}")
                else:
                    time.sleep(0.1)
            except Exception as e:
                print(f"\n[Reader] Error: {e}")
                time.sleep(1)
        else:
            time.sleep(1)

def periodic_sender():
    print("[Periodic Sender] Started.")
    while not shutdown_event.is_set():
        if serial_port and serial_port.is_open:
            try:
                sensor_value = round(20 + random.uniform(-2, 2), 2)
                message = {
                    "destination_meshtastic_id": "!aabbccdd",
                    "payload_json": {"type": "temp", "val": sensor_value}
                }
                message_str = json.dumps(message) + '\n'
                print(f"\n[Sender] >>> {message_str.strip()}")
                serial_port.write(message_str.encode('utf-8'))
            except Exception as e:
                 print(f"\n[Sender] Error: {e}")
        shutdown_event.wait(SENSOR_INTERVAL_S)

def main():
    global serial_port
    print("--- Meshcore Simulator ---")
    reader = threading.Thread(target=serial_reader, daemon=True)
    reader.start()
    if SEND_PERIODIC_SENSOR_DATA:
         sender = threading.Thread(target=periodic_sender, daemon=True)
         sender.start()

    while not shutdown_event.is_set():
        if not serial_port or not serial_port.is_open:
            try:
                serial_port = serial.Serial(SIMULATOR_PORT, BAUD_RATE, timeout=0.5)
                print(f"[Main] Opened {SIMULATOR_PORT}")
            except Exception:
                time.sleep(5)
                continue
        try:
            user_input = input()
            if user_input:
                msg = user_input.encode('utf-8') + b'\n'
                serial_port.write(msg)
        except KeyboardInterrupt:
             break

    shutdown_event.set()
    if serial_port: serial_port.close()

if __name__ == "__main__":
    main()