from fastapi import FastAPI
from pymodbus.client import ModbusSerialClient as ModbusClient
import uvicorn
import threading
import time

app = FastAPI()

# Create a Modbus client instance
client = ModbusClient(method='rtu', port='COM4', baudrate=9600, timeout=1)
client.connect()

# Shared variable to store the Modbus register value
line = '0'

def read_modbus_value():
    global line
    while True:
        # Read holding register (adjust the register address as needed)
        result = client.read_holding_registers(address=1, count=1, unit=1)
        if not result.isError():
            line = str(result.registers[0])
        time.sleep(1)  # Poll every 1 second

# Start the Modbus reading in a separate thread
threading.Thread(target=read_modbus_value, daemon=True).start()

@app.get("/stat")
async def get_stat():
    return {'state': line}

@app.get("/")
async def root():
    return {'message': 'hello world'}

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=12346)