#!/usr/bin/env python
# coding:utf-8

import sys
import os
import re
import time
import socket
import subprocess
import threading
import logging
import xmlrpclib
import SimpleXMLRPCServer
import ConfigParser

USE_PYTHONW = 'C:\\Python27\\pythonw.exe'
SUPERVISORD_CONF = './supervisord.conf'
DEFAULT_PORT = 9001
CURRENT_WATCHDOGS = []

logging.basicConfig(level=logging.INFO, format='%(levelname)s - %(asctime)s %(message)s')


class WatchDog(threading.Thread):
    """a windows process watch dog"""
    TICK_SECONDS = 1
    START_SECONDS = 5

    def __init__(self, name, commandline):
        threading.Thread.__init__(self)
        self.setName(name)
        self._commanline = commandline
        self._birthtime = None
        self._stoped = False
        self._pipe = None

    def run(self):
        close_fds = False if sys.platform == 'win32' else True
        self._pipe = subprocess.Popen(self._commanline, shell=False, close_fds=close_fds)
        self._birthtime = time.time()
        while True:
            try:
                time.sleep(self.TICK_SECONDS)
                if self._stoped:
                    self._pipe.terminate()
                    self._pipe = None
                    return True
                else:
                    if self._pipe.poll() is not None:
                        if time.time() - self._birthtime < self.START_SECONDS:
                            logging.error('WatchDog(%r) start failed', self.getName())
                            self._stoped = True
                            self._pipe = None
                            return False
                        else:
                            logging.error('WatchDog(%r) aborted, try restart', self.getName())
                            self._pipe = subprocess.Popen(self._commanline, shell=False, close_fds=close_fds)
                            self._birthtime = time.time()
                    else:
                        logging.debug('WatchDog(%r) is alive', self.getName())
            except Exception as e:
                logging.exception('WatchDog.run error: %r', e)

    def start(self):
        threading.Thread.start(self)
        return True

    def stop(self):
        self._stoped = True
        timeout = self.START_SECONDS
        while timeout > 0:
            if self._pipe is None:
                return True
            else:
                time.sleep(self.TICK_SECONDS)
                timeout -= self.TICK_SECONDS
        return False


def check_daemon(timeout=1):
    try:
        socket.create_connection(('127.0.0.1', DEFAULT_PORT), timeout=timeout).close()
        return True
    except socket.error:
        return False


def read_service(filename):
    assert os.path.isfile(filename)
    config = ConfigParser.ConfigParser()
    config.read(filename)
    services = {}
    for section in config.sections():
        if section.startswith('program:') and config.has_option(section, 'command'):
            name = section[8:].strip()
            command = config.get(section, 'command').strip()
            if USE_PYTHONW and command.startswith('python'):
                command = ' '.join([USE_PYTHONW] + command.split()[1:])
            services[name] = command
    return services


def clear_stoped_watchdog():
    global CURRENT_WATCHDOGS
    CURRENT_WATCHDOGS = [x for x in CURRENT_WATCHDOGS if not x._stoped and x._pipe]


def do_start(name, commandline):
    clear_stoped_watchdog()
    for watchdog in CURRENT_WATCHDOGS:
        if watchdog.getName() == name:
            msg = 'WatchDog(%r) already started' % name
            logging.error(msg)
            return msg
    watchdog = WatchDog(name, commandline)
    watchdog.start()
    CURRENT_WATCHDOGS.append(watchdog)
    msg = 'WatchDog(%r) started' % watchdog.getName()
    logging.info(msg)
    return msg


def do_stop(name, commandline):
    assert name and commandline
    clear_stoped_watchdog()
    for watchdog in CURRENT_WATCHDOGS:
        if watchdog.getName() == name:
            logging.info('try stoping WatchDog(%r)', name)
            result = watchdog.stop()
            clear_stoped_watchdog()
            if result:
                return 'Stop WatchDog(%r) OK' % watchdog.getName()
            else:
                return 'Stop WatchDog(%r) Error' % watchdog.getName()
    return 'Stop WatchDog(%r) existed, Stop OK' % name


def do_restart(name, commandline):
    msg = do_stop(name, commandline)
    if 'ok' in msg.lower():
        return do_start(name, commandline)
    else:
        return msg


def do_list(name, commandline):
    assert name and commandline
    clear_stoped_watchdog()
    return os.linesep.join('%s PID:%s' % (x.getName(), x._pipe.pid) for x in CURRENT_WATCHDOGS)


def supervisord():
    server = SimpleXMLRPCServer.SimpleXMLRPCServer(('', DEFAULT_PORT), logRequests=True)
    server.register_function(do_start)
    server.register_function(do_stop)
    server.register_function(do_restart)
    server.register_function(do_list)
    server.serve_forever()


def supervisorctl():
    argstr = ' '.join(sys.argv[1:])
    m = re.search('--service=(\w+)', argstr)
    service = m.group(1) if m else 'node_agent'
    m = re.search('-c\s+(\w+)', argstr)
    action = m.group(1) if m else ''
    filename = os.path.join(os.path.dirname(os.path.abspath(__file__)), SUPERVISORD_CONF)
    conf_services = read_service(filename)
    services = conf_services.keys() if service == 'all' else [service]
    for service in services:
        if service not in conf_services:
            logging.error('cannot found service=%r in %r', service, filename)
        proxy = xmlrpclib.ServerProxy('http://localhost:%d' % DEFAULT_PORT)
        if action == 'start':
            print(proxy.do_start(service, conf_services[service]))
        elif action == 'stop':
            print(proxy.do_stop(service, conf_services[service]))
        elif action == 'restart':
            print(proxy.do_restart(service, conf_services[service]))
        else:
            print(proxy.do_list(service, conf_services[service]))


def main():
    if '--daemon' in sys.argv[1:]:
        supervisord()
        sys.exit(0)
    if not check_daemon():
        if USE_PYTHONW:
            close_fds = False if sys.platform == 'win32' else True
            cmd = '%s "%s" --daemon' % (USE_PYTHONW, os.path.abspath(__file__))
            subprocess.Popen(cmd, close_fds=close_fds)
        else:
            cmd = 'start "%s" "%s" --daemon' % (sys.executable, os.path.abspath(__file__))
            os.system(cmd)
    supervisorctl()


if __name__ == '__main__':
    main()