import serial
import time
import os
import sys

PORT = '/dev/cu.usbmodem101'
print("=== MicroPython Boot Interrupter & Recovery Tool ===")
print(f"Waiting for {PORT} to appear. Please press the RESET button on the board...")

while True:
    try:
        ser = serial.Serial(PORT, 115200, timeout=1.0)
        print("\n[+] Port opened successfully!")
        break
    except Exception as e:
        # Port not present or busy
        time.sleep(0.01)

print("[*] Sending Ctrl-C storm to halt boot sequence...")
# Send 100 Ctrl-C interrupts in rapid succession
for _ in range(100):
    try:
        ser.write(b'\x03')
        time.sleep(0.005)
    except Exception as e:
        print(f"Write error during storm: {e}")
        break

time.sleep(0.1)
ser.reset_input_buffer()

# Check if we have REPL access by sending a newline and expecting a prompt
print("[*] Verifying REPL responsiveness...")
ser.write(b'\r\n')
time.sleep(0.2)

if ser.in_waiting:
    resp = ser.read(ser.in_waiting)
    print(f"REPL Response:\n{resp.decode('utf-8', errors='ignore')}")
else:
    print("[-] No response to newline, trying to force it...")
    ser.write(b'\x03\r\n')
    time.sleep(0.2)
    resp = ser.read(ser.in_waiting)
    print(f"REPL Response:\n{resp.decode('utf-8', errors='ignore')}")

# Try to rename main.py to stop it from running on subsequent boots
print("[*] Attempting to disable main.py...")
rename_code = b"""
import os
try:
    os.rename('main.py', 'main_bad.py')
    print('RENAME:OK')
except Exception as e:
    print('RENAME:ERROR:', e)
"""
ser.write(rename_code + b'\r\n')
time.sleep(0.5)

if ser.in_waiting:
    result = ser.read(ser.in_waiting).decode('utf-8', errors='ignore')
    print(f"Execution Output:\n{result}")
    if "RENAME:OK" in result:
        print("[+] SUCCESS! main.py has been disabled.")
        print("[+] You can now safely upload files or reboot.")
    else:
        print("[-] Rename failed or returned unexpected output.")
else:
    print("[-] No response to rename command.")

ser.close()