#!/usr/bin/env python3
"""
Mock llama-server process for NixOS VM tests.

Sets /proc/self/comm to "llama-server" via prctl so that monitoring scripts
(llama-cpp-annotations, llama-cpp-xmrig-pause) can discover this process
the same way they discover the real one.

Usage: python3 mock-llama-server-proc.py <state-file>

The state file controls behavior:
  "busy"  -> burn CPU in a tight loop (simulates prompt processing / inference)
  "idle"  -> sleep (simulates waiting for requests)
"""

import ctypes
import ctypes.util
import sys
import time

STATE_FILE = sys.argv[1]

# PR_SET_NAME = 15, sets /proc/self/comm
libc = ctypes.CDLL(ctypes.util.find_library("c"), use_errno=True)
libc.prctl(15, b"llama-server", 0, 0, 0)

with open(STATE_FILE, "w") as f:
    f.write("idle")

while True:
    try:
        with open(STATE_FILE) as f:
            state = f.read().strip()
    except Exception:
        state = "idle"

    if state == "busy":
        end = time.monotonic() + 0.1
        while time.monotonic() < end:
            _ = sum(range(10000))
    else:
        time.sleep(0.5)