#!/usr/bin/env python

import sys, os, signal, subprocess, shlex, time, atexit

shutdown = False
queue_process = None


def file_pid(name):
	proc1 = subprocess.Popen(shlex.split('ps aux'), stdout=subprocess.PIPE)
	proc2 = subprocess.Popen(shlex.split('grep ' + name), stdin=proc1.stdout, stdout=subprocess.PIPE,stderr=subprocess.PIPE)
	proc3 = subprocess.Popen(shlex.split('awk \'{print $2}\' '), stdin=proc2.stdout, stdout=subprocess.PIPE,stderr=subprocess.PIPE)

	proc1.stdout.close()
	proc2.stdout.close()
	out, err = proc3.communicate()

	lines = out.splitlines()
	pids = []
	for line in lines:
		item = line.strip()
		pid = int(item)
		if pid > 0:
			pids.append(pid)

	if len(pids) > 0:
		return pids
	else:
		return []


def kill_pid(name):
	print("kill_pid " + name)
	cur_pid = os.getpid()
	pids = file_pid(name)
	for pid in pids:
		try:
			if cur_pid != pid:
				os.kill(pid, signal.SIGKILL)
				print('kill pid=' + str(pid))
			else:
				continue
		except OSError as e:
			pass
		except BaseException as be:
			pass
	return


def sig_handler(sig, frame):
	global shutdown
	global queue_process

	frame = None
	if sig == signal.SIGINT:
		shutdown = True
	elif sig == signal.SIGTERM:
		shutdown = True

	if shutdown == True and queue_process != None:
		for proc in queue_process:
			proc.terminate()


class Daemon(object):
	def __init__(self, input='/dev/null', output='/tmp/qwatch.out'):
		self.infile = input
		self.outfile = output

	def register_handler(self):
		signal.signal(signal.SIGINT, sig_handler)
		signal.signal(signal.SIGTERM, sig_handler)
		signal.signal(signal.SIGCHLD, sig_handler)

	def daemonize(self):
		try:
			pid = os.fork()
			if pid != 0:
				sys.exit(0)
		except OSError as e:
			sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
			sys.exit(1)

		os.setsid()
		os.umask(0)

		try:
			pid = os.fork()
			if pid != 0:
				sys.exit(0)
		except OSError as e:
			sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
			sys.exit(1)

		os.close(0)
		os.close(1)
		os.close(2)

		os.open(self.infile, os.O_RDONLY)
		os.open(self.outfile, os.O_WRONLY | os.O_APPEND | os.O_CREAT)
		os.dup(1)
		print("********************************************************")


def mac_sys():
	plat_name = sys.platform
	return plat_name == 'darwin'


def main():
	global queue_process

	kill_pid("qwatch.py")
	kill_pid("crontab.php")

	queue_process = list()

	d = Daemon()
	d.daemonize()
	d.register_handler()

	print("cur_pid =" + str(os.getpid()))

	if mac_sys():
		cmds = ["php", "./crontab.php", "queue", "index"]
		proc_num = 1
	else:
		cmds = ["/usr/local/php/bin/php", "./crontab.php", "queue", "index"]
		proc_num = 10

	for i in range(0, proc_num):
		subproc = subprocess.Popen(cmds, close_fds=True, stdin=None, stdout=None, stderr=None)
		queue_process.append(subproc)
		print("create queue process pid=" + str(subproc.pid))

	while shutdown == False:
		time.sleep(1)
		for process in queue_process:
			if process.poll() is not None:
				print (str(process.pid) + " is dead.")
				queue_process.remove(process)
				child = subprocess.Popen(cmds, close_fds=True, stdin=None, stdout=None, stderr=None)
				print("create queue process pid=" + str(child.pid))
				queue_process.append(child)


if __name__ == '__main__':
	main()