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

# Copyright (c) 2014 clowwindy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import sys
import logging
import struct
import time
from shadowsocks import shell, eventloop, tcprelay, udprelay, asyncdns, common
import threading
import traceback
from socket import *
from configloader import get_config


class MainThread(threading.Thread):
    def __init__(self, params):
        super(MainThread, self).__init__()
        self.params = params

    def run(self):
        ServerPool._loop(*self.params)


class ServerPool(object):
    instance = None

    def __init__(self):
        shell.check_python()
        self.config = shell.get_config(False)
        self.dns_resolver = asyncdns.DNSResolver()
        if not self.config.get('dns_ipv6', False):
            asyncdns.IPV6_CONNECTION_SUPPORT = False

        self.mgr = None  # asyncmgr.ServerMgr()

        self.tcp_servers_pool = {}
        self.tcp_ipv6_servers_pool = {}
        self.udp_servers_pool = {}
        self.udp_ipv6_servers_pool = {}
        self.stat_counter = {}

        self.loop = eventloop.EventLoop()
        self.thread = MainThread((self.loop, self.dns_resolver, self.mgr))
        self.thread.start()

    @staticmethod
    def get_instance():
        if ServerPool.instance is None:
            ServerPool.instance = ServerPool()
        return ServerPool.instance

    def stop(self):
        self.loop.stop()

    @staticmethod
    def _loop(loop, dns_resolver, mgr):
        try:
            if mgr is not None:
                mgr.add_to_loop(loop)
            dns_resolver.add_to_loop(loop)
            loop.run()

        except (KeyboardInterrupt, IOError, OSError) as e:
            logging.error(e)
            traceback.print_exc()
            sys.exit(0)

        except Exception as e:
            logging.error(e)
            traceback.print_exc()

    def server_is_run(self, port):
        port = int(port)
        ret = 0
        if port in self.tcp_servers_pool:
            ret = 1
        if port in self.tcp_ipv6_servers_pool:
            ret |= 2
        return ret

    def server_run_status(self, port):
        if 'server' in self.config:
            if port not in self.tcp_servers_pool:
                return False
        if 'server_ipv6' in self.config:
            if port not in self.tcp_ipv6_servers_pool:
                return False
        return True

    def new_server(self, port, user_config):
        ret = True
        port = int(port)
        ipv6_ok = False

        if 'server_ipv6' in self.config:
            if port in self.tcp_ipv6_servers_pool:
                logging.info("server already at %s:%d" % (self.config['server_ipv6'], port))
                return 'this port server is already running'
            else:
                a_config = self.config.copy()
                a_config.update(user_config)
                if len(a_config['server_ipv6']) > 2 \
                        and a_config['server_ipv6'][0] == "[" \
                        and a_config['server_ipv6'][-1] == "]":
                    a_config['server_ipv6'] = a_config['server_ipv6'][1:-1]

                a_config['server'] = a_config['server_ipv6']
                a_config['server_port'] = port
                a_config['max_connect'] = 128
                a_config['method'] = common.to_str(a_config['method'])

                try:
                    logging.info("starting server at [%s]:%d" % (common.to_str(a_config['server']), port))

                    tcp_server = tcprelay.TCPRelay(a_config, self.dns_resolver, False, stat_counter=self.stat_counter)
                    tcp_server.add_to_loop(self.loop)
                    self.tcp_ipv6_servers_pool.update({port: tcp_server})

                    udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False, stat_counter=self.stat_counter)
                    udp_server.add_to_loop(self.loop)
                    self.udp_ipv6_servers_pool.update({port: udp_server})

                    if common.to_str(a_config['server_ipv6']) == "::":
                        ipv6_ok = True
                except Exception as e:
                    logging.warning("IPV6 %s " % (e,))

        if 'server' in self.config:
            if port in self.tcp_servers_pool:
                logging.info("server already at %s:%d" % (common.to_str(self.config['server']), port))
                return 'this port server is already running'
            else:
                a_config = self.config.copy()
                a_config.update(user_config)
                a_config['server_port'] = port
                a_config['max_connect'] = 128
                a_config['method'] = common.to_str(a_config['method'])
                try:
                    logging.info("starting server at %s:%d" % (common.to_str(a_config['server']), port))

                    tcp_server = tcprelay.TCPRelay(a_config, self.dns_resolver, False)
                    tcp_server.add_to_loop(self.loop)
                    self.tcp_servers_pool.update({port: tcp_server})

                    udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False)
                    udp_server.add_to_loop(self.loop)
                    self.udp_servers_pool.update({port: udp_server})

                except Exception as e:
                    if not ipv6_ok:
                        logging.warning("IPV4 %s " % (e,))

        return True

    def del_server(self, port):
        port = int(port)
        logging.info("del server at %d" % port)
        try:
            udpsock = socket(AF_INET, SOCK_DGRAM)
            udpsock.sendto('%s:%s:0:0' % (get_config().MANAGE_PASS, port),
                           (get_config().MANAGE_BIND_IP, get_config().MANAGE_PORT))
            udpsock.close()
        except Exception as e:
            logging.warning(e)
        return True

    def cb_del_server(self, port):
        port = int(port)

        if port not in self.tcp_servers_pool:
            logging.info("stopped server at %s:%d already stop" % (self.config['server'], port))
        else:
            logging.info("stopped server at %s:%d" % (self.config['server'], port))
            try:
                self.tcp_servers_pool[port].close(True)
                del self.tcp_servers_pool[port]
            except Exception as e:
                logging.warning(e)
            try:
                self.udp_servers_pool[port].close(True)
                del self.udp_servers_pool[port]
            except Exception as e:
                logging.warning(e)

        if 'server_ipv6' in self.config:
            if port not in self.tcp_ipv6_servers_pool:
                logging.info("stopped server at [%s]:%d already stop" % (self.config['server_ipv6'], port))
            else:
                logging.info("stopped server at [%s]:%d" % (self.config['server_ipv6'], port))
                try:
                    self.tcp_ipv6_servers_pool[port].close(True)
                    del self.tcp_ipv6_servers_pool[port]
                except Exception as e:
                    logging.warning(e)
                try:
                    self.udp_ipv6_servers_pool[port].close(True)
                    del self.udp_ipv6_servers_pool[port]
                except Exception as e:
                    logging.warning(e)

        return True

    def update_mu_users(self, port, users):
        port = int(port)
        if port in self.tcp_servers_pool:
            try:
                self.tcp_servers_pool[port].update_users(users)
            except Exception as e:
                logging.warning(e)
            try:
                self.udp_servers_pool[port].update_users(users)
            except Exception as e:
                logging.warning(e)
        if port in self.tcp_ipv6_servers_pool:
            try:
                self.tcp_ipv6_servers_pool[port].update_users(users)
            except Exception as e:
                logging.warning(e)
            try:
                self.udp_ipv6_servers_pool[port].update_users(users)
            except Exception as e:
                logging.warning(e)

    def get_server_transfer(self, port):
        port = int(port)
        uid = struct.pack('<I', port)
        ret = [0, 0]
        if port in self.tcp_servers_pool:
            ret[0], ret[1] = self.tcp_servers_pool[port].get_ud()
        if port in self.udp_servers_pool:
            u, d = self.udp_servers_pool[port].get_ud()
            ret[0] += u
            ret[1] += d
        if port in self.tcp_ipv6_servers_pool:
            u, d = self.tcp_ipv6_servers_pool[port].get_ud()
            ret[0] += u
            ret[1] += d
        if port in self.udp_ipv6_servers_pool:
            u, d = self.udp_ipv6_servers_pool[port].get_ud()
            ret[0] += u
            ret[1] += d
        return ret

    def get_server_mu_transfer(self, server):
        return server.get_users_ud()

    def update_mu_transfer(self, user_dict, u, d):
        for uid in u:
            port = struct.unpack('<I', uid)[0]
            if port not in user_dict:
                user_dict[port] = [0, 0]
            user_dict[port][0] += u[uid]
        for uid in d:
            port = struct.unpack('<I', uid)[0]
            if port not in user_dict:
                user_dict[port] = [0, 0]
            user_dict[port][1] += d[uid]

    def get_servers_transfer(self):
        servers = self.tcp_servers_pool.copy()
        servers.update(self.tcp_ipv6_servers_pool)
        servers.update(self.udp_servers_pool)
        servers.update(self.udp_ipv6_servers_pool)
        ret = {}
        for port in servers.keys():
            ret[port] = self.get_server_transfer(port)
        for port in self.tcp_servers_pool:
            u, d = self.get_server_mu_transfer(self.tcp_servers_pool[port])
            self.update_mu_transfer(ret, u, d)
        for port in self.tcp_ipv6_servers_pool:
            u, d = self.get_server_mu_transfer(self.tcp_ipv6_servers_pool[port])
            self.update_mu_transfer(ret, u, d)
        for port in self.udp_servers_pool:
            u, d = self.get_server_mu_transfer(self.udp_servers_pool[port])
            self.update_mu_transfer(ret, u, d)
        for port in self.udp_ipv6_servers_pool:
            u, d = self.get_server_mu_transfer(self.udp_ipv6_servers_pool[port])
            self.update_mu_transfer(ret, u, d)
        return ret