import runpy
import os
import sys
import time
import threading


# in milliseconds
SAMPLE_INTERVAL = 10


def die(message):
    print(message, file=sys.stderr)
    # use 'os' over 'sys', since we are calling from a child thread
    os._exit(1)


def get_main_thread_id():
    for thread_id, frame in sys._current_frames().items():
        if threading.main_thread().ident == thread_id:
            return thread_id
    die("[mini-scalene] Couldn't find main thread--likely an unimplemented feature.")


def sample_running_function():
    main_thread_id = get_main_thread_id()

    frame = sys._current_frames()[main_thread_id]
    code = frame.f_code
    print(f"[mini-scalene] Currently executing: {code.co_name} in {code.co_filename}:{frame.f_lineno}")


def sampling_loop():
    while True:
        sample_running_function()
        time.sleep(SAMPLE_INTERVAL / 1000.0)


def main():
    if len(sys.argv) < 2:
        die("[mini-scalene] (Usage): python3 mini-scalene.py file.py {args ...}")

    script = sys.argv[1]
    sys.argv = sys.argv[1:]

    t = threading.Thread(target=sampling_loop, daemon=True)
    t.start()

    try:
        runpy.run_path(script, run_name="__main__")
    except Exception as e:
        die(f"[mini-scalene] Script died unexpectedly: {e}")


if __name__ == "__main__":
    main()