#!/usr/bin/env python3
import os
import sys
import re
import subprocess
import signal
import time
import datetime
import traceback
from threading import Thread
import importlib.machinery as imp
#################################################################################
# Search for data folder

__all_data_folders__ = (
		os.path.dirname(__file__),
		'.',
		'~/mcwrapper',
		'/usr/share/mcwrapper',
		)

def __is_data_folder__(path):
	if os.path.isdir(path + '/modules') and \
	os.path.isfile(path + '/modules/utils.py'):
	   return True
	else:
		return False

def __data_folder_missing__(path):
	if not os.path.isdir(path + '/modules'):
		print('Folder ' + path + 'modules not found.')
		if not os.path.isfile(path + '/modules/utils.py'):
			print('File ' + path + '/modules/utils.py not found.')

__data_folder__ = None
try:
	__data_folder__ = os.environ['DATAF']
	if not __is_data_folder__(__data_folder__):
		print("Error: " + __data_folder__ + " doesn't seems to be mcwrapper data folder.", file=sys.stderr)
		sys.exit(2)
except KeyError:
	for df in __all_data_folders__:
		if os.path.isdir(df):
			__data_folder__ = df
			break
	if __data_folder__ == None:
		print("Error: No mcwrapper data folder found.", file=sys.stderr)
		sys.exit(1)

#################################################################################
# Load and set utils

utils = imp.SourceFileLoader("utils",
		__data_folder__ + '/modules/utils.py').load_module()

#################################################################################
# Load configuration

__all_config_files__ = (
		'mcwrapper.conf',
		'~/.mcwrapper.conf',
		'~/.config/mcwrapper.conf',
		'/etc/mcwrapper.conf',
		)

def __set_empty_config__():
	global conf
	print('Warning: User configuration not loaded. Using default.', file=sys.stderr)
	conf = type('defconf', (object,), {})

__config_file__ = None
try:
	__config_file__ = os.environ['CONFIG']
except KeyError:
	for cf in __all_config_files__:
		if os.path.isfile(cf):
			__config_file__ = cf
			break
if __config_file__ == None:
	__set_empty_config__()
else:
	try:
		conf = imp.SourceFileLoader("conf", __config_file__).load_module()
	except Exception:
		traceback.print_exc()
		__set_empty_config__()

# Set conf to utils
utils.conf = conf

utils.configSet(utils.__default_config__)
# Set additional runtime configuration variables
conf.verbose_level = 0
conf.action = None
conf.action_module = None
conf.command = []
conf.__modules_action__  = set()
conf.__modules_argument__ = set()
conf.modulesFolder = __data_folder__ + '/modules'

#################################################################################
# Modules management

def __module_load__(modname):
	try:
		module = imp.SourceFileLoader(modname,
				conf.modulesFolder + '/' + modname + '.py').load_module()
		return module
	except FileNotFoundError:
		if conf.verbose_level >= -2:
			print("Error: Unknown module " + mod, file=sys.stderr)
		sys.exit(3)

def __module_unload__(mod):
	for name, value in vars(conf):
		if re.search('^__modules', name):
			try:
				value.remote(mod)
			except KeyError:
				pass
	del mod

# Load global modules
for mod in conf.modules:
	module = __module_load__(mod)
	if utils.Service.action in module.services:
		conf.__modules_action__.add(module)
	if utils.Service.argument in module.services:
		conf.__modules_argument__.add(module)

def server_modules_load():
	conf.__modules_config__  = set()
	conf.__modules_init__    = set()
	conf.__modules_clean__   = set()
	conf.__modules_parse__   = set()
	for mod in conf.modules:
		if conf.verbose_level >= 1:
			print('Loading module: ' + mod)
		module = __module_load__(mod)
		if utils.Service.config in module.services:
			conf.__modules_config__.add(module)
		if utils.Service.init in module.services:
			conf.__modules_init__.add(module)
		if utils.Service.clean in module.services:
			conf.__modules_clean__.add(module)
		if utils.Service.parse in module.services:
			conf.__modules_parse__.add(module)

#################################################################################

def __server_init__(identifier):
	if conf.verbose_level >= 0:
		print("Wrapper initializing with identifier: " + identifier)
	try:
		os.mkdir(conf.folder)
	except FileExistsError:
		pass
	if os.path.isfile(conf.inputPipe):
		if conf.verbose_level >= 2:
			print("Error: Server input pipe already exists. Is another wrapper running?")
		sys.exit(4)
	os.mkfifo(conf.inputPipe, 0o640)
	utils.serviceCall('init', 'init')

def __server_clean__():
	if conf.verbose_level >= 0:
		print("Wrapper clean.")
	utils.serviceCall('clean', 'clean')
	try:
		os.remove(conf.inputPipe)
	except FileNotFoundError:
		pass

def __parse_line__(line):
	utils.serviceCall('parse', 'parse', [line], 2)

#################################################################################

class __InputThread__(Thread):
	def __init__(self, pipein, pipeprocess):
		Thread.__init__(self, name='InputThread')
		self.pipein = pipein
		self.pipeprocess = pipeprocess
		self.stopread = False
	def stopexec(self):
		self.stopread = True
	def wake(self):
		with open(self.pipein, 'w') as f:
			f.write("\n")
			f.flush()
	def run(self):
		with open(self.pipein, 'r') as p:
			while not self.stopread:
				ln = p.readline()
				if ln.rstrip():
					if conf.verbose_level >= 1:
						print("Input: " + ln, end="")
					self.pipeprocess.write(bytes(ln, sys.getdefaultencoding()))
					self.pipeprocess.flush()
				else:
					time.sleep(1)
			try:
				os.remove(conf.inputPipe)
			except FileNotFoundError:
				pass

def __server_send_stop__():
	global prc
	prc.stdin.write(bytes("/stop\n", sys.getdefaultencoding()))
	prc.stdin.flush()

def mcexec(identifier, cmd):
	"""Executes cmd and parses output for server status changes.
    """
	global prc
	__server_init__(conf.identifier)
	if conf.logOutput:
		try:
			os.makedirs(os.path.dirname(conf.logFile))
		except FileExistsError:
			pass
	if type(cmd) != str:
		cmd = ' '.join(cmd)
	if conf.verbose_level >= 1:
		print("Start command: " + cmd)
	prc = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
			stderr=subprocess.STDOUT, shell=True)
	inputThread = __InputThread__(conf.inputPipe, prc.stdin)
	inputThread.start()
	inputThread.wake() # Input thread is stuck in waiting for first line
	for linen in prc.stdout:
		line = linen.decode(sys.getdefaultencoding())
		if conf.verbose_level >= 2:
			print(line.rstrip())
		if conf.logOutput:
			with open(conf.logFile, 'a') as flg:
				flg.write(line)
		__parse_line__(line.rstrip())
	inputThread.stopexec()
	__server_clean__()

#################################################################################

def __signal_term__(_signo, _stack_frame):
	__server_send_stop__()

def action_start_exec():
	if not conf.identifier:
		argument_help_exec()
		return
	server_modules_load()
	utils.serviceCall('config', 'config', [conf])
	if not conf.command:
		argument_help_exec()
		return
	signal.signal(signal.SIGTERM, __signal_term__)
	signal.signal(signal.SIGINT, __signal_term__)
	mcexec(conf.identifier, conf.command)


def action_stop_exec():
	if not conf.identifier:
		argument_help_exec()
		return
	if not os.path.exists(conf.inputPipe):
		sys.exit("Such server is not running")
	with open(conf.inputPipe, 'w') as f:
		f.write("/stop\n")
		f.flush()
	while os.path.exists(conf.inputPipe):
		pass

def argument_help_exec():
	if conf.action_module == None:
		if conf.action == 'start':
			print('mcwrapper [arguments...] start IDENTIFIER {command...}')
			print('  Start server under "IDENTIFIER" with command "command"')
			print('')
			print(' arguments')
			utils.printArgumentsHelp()
			print(' IDENTIFIER')
			print('   Identifier for new server instance. This allows multiple server')
			print('   instances running with this wrapper.')
			print('   Identifier is word without spaces and preferably without special')
			print('   characters.')
			print(' command')
			print('   Command to execute Minecraft server.')
		elif conf.action == 'stop':
			print('mcwrapper [arguments...] stop IDENTIFIER')
			# TODO
		else:
			print('mcwrapper [arguments...] ACTION ...')
			print('  This script is executing Minecraft server and reads its output.')
			print('')
			print(' arguments')
			utils.printArgumentsHelp()
			print('')
			print(' ACTION')
			print('   start')
			print('       Starts server.')
			print('   stop')
			print('       Sends stop command to Minecraft server.')
			for mod in conf.__modules_action__:
				mod.action_help()
			print('')
			print('For more informations abou specific actions enter --help')
			print('with ACTION argument.')
	else:
		conf.action_module.action_full_help()

#################################################################################

if __name__ == '__main__':
	print_help = False
	arguments = set()
	i = 1
	while i < len(sys.argv):
		arg = sys.argv[i]
		if arg[0] == '-':
			if len(arg) > 2 and arg[1] == '-':
				cnt, mod = utils.serviceCall('argument', 'argument', [sys.argv[i:]], 2)
				if cnt:
					arguments.add(mod)
					i += cnt
					continue
				if arg == '--help':
					print_help = True
					i += 1
					continue
				if arg == '--verbose':
					conf.verbose_level += 1
					i += 1
					continue
				if arg == '--quiet':
					conf.verbose_level += 1
					i += 1
					continue
			else:
				docontinue = False
				i += 1
				for l in arg[1:]:
					cnt, mod = utils.serviceCall('argument', 'argument_short',
							[l, sys.argv[i:]], 2)
					if cnt:
						arguments.add(mod)
						i += cnt
						docontinue = True
					elif l == 'h':
						print_help = True
						docontinue = True
					elif l == 'v':
						conf.verbose_level += 1
						docontinue = True
					elif l == 'q':
						conf.verbose_level -= 1
						docontinue = True
				if docontinue:
					continue
		if conf.action == None:
			rtn, mod = utils.serviceCall('action', 'action', [sys.argv[i:]], 2)
			if rtn:
				i += rtn
				continue
			if arg.lower() == 'start':
				conf.action = 'start'
				for arg in sys.argv[i+1:]:
					if conf.identifier == None:
						conf.identifier = arg
					else:
						if type(conf.command) == str:
							conf.command += arg
						else:
							conf.command.append(arg)
				break
			if arg.lower() == 'stop':
				conf.action = 'stop'
				i += 1
				continue
		else:
			if conf.action_module == None:
				if conf.action == 'stop':
					if not conf.identifier:
						conf.identifier = args[0]
						i += 1
						continue
			else:
				cnt = conf.action_module.action(sys.argv[i:])
				if cnt:
					i += cnt
					continue
		sys.exit("Unknown argument: " + arg)


	if conf.identifier:
		utils.setServerConf(conf.identifier)
	for mod in arguments:
		mod.argument_exec()
	if print_help:
		argument_help_exec()
		sys.exit()
	if conf.action_module != None:
		conf.action_module.action_exec()
	else:
		if conf.action == 'start':
			action_start_exec()
		elif conf.action == 'stop':
			action_stop_exec()
		else:
			pass # This shouldn't happen