#!/usr/bin/python3
import io
import os
import pwd
import subprocess
import psutil
import mmap
import time
import resource
from jelka_config import luči
from sys import argv
if not os.getenv("DRY_RUN"):
	import jelka_hardware

def izriši():
	if os.getenv("DRY_RUN"):
		print("wrapper: ", end="")
		for i in range(luči*3):
			print(f"{buffer[i]:02x}", end="")
		print()
		return
	for i in range(luči):
		jelka_hardware.nastavi(i, (buffer[3*i], buffer[3*i+1], buffer[3*i+2]))
	jelka_hardware.izriši()

def demote(uid, gid, chrootpath):
	def result():
		resource.setrlimit(resource.RLIMIT_NPROC, (1, 1))
		os.chroot(chrootpath)
		os.setgid(gid)
		os.setuid(uid)
	return result

shmf = open("chroot/dev/shm/jelka", mode="w+b")
os.ftruncate(shmf.fileno(), luči*3)
buffer = mmap.mmap(shmf.fileno(), 0)
cwd = "/"
r, w = os.pipe()
args = ["/jelka/vzorci/" + argv[1], str(w)]
pw_record = pwd.getpwnam("umetnik")
os.chown("chroot/dev/shm/jelka", 0, pw_record.pw_gid)
os.chmod("chroot/dev/shm/jelka", 0o660)
env = os.environ.copy()
env["HOME"] = pw_record.pw_dir
env["LOGNAME"] = pw_record.pw_name
env["PWD"] = cwd
env["USER"] = pw_record.pw_name
env["PYTHONPATH"] = "/jelka"
process = subprocess.Popen(
	args, preexec_fn=demote(pw_record.pw_uid, pw_record.pw_uid, os.path.abspath("chroot")), cwd=cwd, env=env, pass_fds=[w]
)
try:
	while io.FileIO(r, closefd=False).read(1):
		izriši()
	result = process.wait()
	buffer.close()
	shmf.close()
except:
	print("cleaning up!")
	process.kill()