import serial
import sys
import time

PORT = "/dev/ttyUSB0"
BAUDRATE = 115200
TIMEOUT = 2
MAX_WAIT = 10

COMMAND = "bdinfo"

try:
    with serial.Serial(
        port=PORT,
        baudrate=BAUDRATE,
        timeout=0.2,
        write_timeout=TIMEOUT
    ) as ser:

        print(f"Connected to {PORT}", flush=True)

        # Clear old serial data
        ser.reset_input_buffer()

        # Send command to U-Boot
        ser.write((COMMAND + "\r").encode())
        ser.flush()

        print(f"Command sent: {COMMAND}", flush=True)
        print("------ U-Boot Response ------", flush=True)

        response = bytearray()
        start_time = time.monotonic()
        last_data_time = start_time

        while time.monotonic() - start_time < MAX_WAIT:

            if ser.in_waiting:
                data = ser.read(ser.in_waiting)
                response.extend(data)

                # Print response in real time
                print(
                    data.decode("utf-8", errors="replace"),
                    end="",
                    flush=True
                )

                last_data_time = time.monotonic()

            # Stop when no new data arrives for 2 seconds
            if response and time.monotonic() - last_data_time > TIMEOUT:
                break

            time.sleep(0.05)

        print("\n-----------------------------")

        if not response:
            print("ERROR: No response from U-Boot")
            sys.exit(1)

        print("Command completed successfully")

except serial.SerialException as e:
    print(f"Serial error: {e}")
    sys.exit(1)