/*
 * Copyright (C) 2008-2014 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/// \addtogroup Trinityd Trinity Daemon
/// @{
/// \file

#include <openssl/opensslv.h>
#include <openssl/crypto.h>
#include <boost/asio/io_service.hpp>
#include <boost/asio/deadline_timer.hpp>
#include <boost/program_options.hpp>

#include "Common.h"
#include "DatabaseEnv.h"
#include "AsyncAcceptor.h"
#include "RASession.h"
#include "Configuration/Config.h"
#include "OpenSSLCrypto.h"
#include "ProcessPriority.h"
#include "BigNumber.h"
#include "RealmList.h"
#include "World.h"
#include "MapManager.h"
#include "InstanceSaveMgr.h"
#include "ObjectAccessor.h"
#include "ScriptMgr.h"
#include "OutdoorPvP/OutdoorPvPMgr.h"
#include "BattlegroundMgr.h"
#include "TCSoap.h"
#include "CliRunnable.h"
#include "SystemConfig.h"
#include "WorldSocket.h"
#include "WorldSocketMgr.h"

using namespace boost::program_options;

#ifndef _TRINITY_CORE_CONFIG
    #define _TRINITY_CORE_CONFIG  "worldserver.conf"
#endif

#define WORLD_SLEEP_CONST 50

#ifdef _WIN32
#include "ServiceWin32.h"
char serviceName[] = "worldserver";
char serviceLongName[] = "TrinityCore world service";
char serviceDescription[] = "TrinityCore World of Warcraft emulator world service";
/*
 * -1 - not in service mode
 *  0 - stopped
 *  1 - running
 *  2 - paused
 */
int m_ServiceStatus = -1;
#endif

boost::asio::io_service _ioService;
boost::asio::deadline_timer _freezeCheckTimer(_ioService);
uint32 _worldLoopCounter(0);
uint32 _lastChangeMsTime(0);
uint32 _maxCoreStuckTimeInMs(0);

WorldDatabaseWorkerPool WorldDatabase;                      ///< Accessor to the world database
CharacterDatabaseWorkerPool CharacterDatabase;              ///< Accessor to the character database
LoginDatabaseWorkerPool LoginDatabase;                      ///< Accessor to the realm/login database
uint32 realmID;                                             ///< Id of the realm

void SignalHandler(const boost::system::error_code& error, int signalNumber);
void FreezeDetectorHandler(const boost::system::error_code& error);
AsyncAcceptor* StartRaSocketAcceptor(boost::asio::io_service& ioService);
bool StartDB();
void StopDB();
void WorldUpdateLoop();
void ClearOnlineAccounts();
void ShutdownThreadPool(std::vector<std::thread>& threadPool);
variables_map GetConsoleArguments(int argc, char** argv, std::string& cfg_file, std::string& cfg_service);

/// Launch the Trinity server
extern int main(int argc, char** argv)
{
    std::string configFile = _TRINITY_CORE_CONFIG;
    std::string configService;

    auto vm = GetConsoleArguments(argc, argv, configFile, configService);
    // exit if help is enabled
    if (vm.count("help"))
        return 0;

#ifdef _WIN32
    if (configService.compare("install") == 0)
        return WinServiceInstall() == true ? 0 : 1;
    else if (configService.compare("uninstall") == 0)
        return WinServiceUninstall() == true ? 0 : 1;
    else if (configService.compare("run") == 0)
        WinServiceRun();
#endif

    std::string configError;
    if (!sConfigMgr->LoadInitial(configFile, configError))
    {
        printf("Error in config file: %s\n", configError.c_str());
        return 1;
    }

    if (sConfigMgr->GetBoolDefault("Log.Async.Enable", false))
    {
        // If logs are supposed to be handled async then we need to pass the io_service into the Log singleton
        Log::instance(&_ioService);
    }

    TC_LOG_INFO("server.worldserver", "%s (worldserver-daemon)", _FULLVERSION);
    TC_LOG_INFO("server.worldserver", "<Ctrl-C> to stop.\n");
    TC_LOG_INFO("server.worldserver", " ______                       __");
    TC_LOG_INFO("server.worldserver", "/\\__  _\\       __          __/\\ \\__");
    TC_LOG_INFO("server.worldserver", "\\/_/\\ \\/ _ __ /\\_\\    ___ /\\_\\ \\, _\\  __  __");
    TC_LOG_INFO("server.worldserver", "   \\ \\ \\/\\`'__\\/\\ \\ /' _ `\\/\\ \\ \\ \\/ /\\ \\/\\ \\");
    TC_LOG_INFO("server.worldserver", "    \\ \\ \\ \\ \\/ \\ \\ \\/\\ \\/\\ \\ \\ \\ \\ \\_\\ \\ \\_\\ \\");
    TC_LOG_INFO("server.worldserver", "     \\ \\_\\ \\_\\  \\ \\_\\ \\_\\ \\_\\ \\_\\ \\__\\\\/`____ \\");
    TC_LOG_INFO("server.worldserver", "      \\/_/\\/_/   \\/_/\\/_/\\/_/\\/_/\\/__/ `/___/> \\");
    TC_LOG_INFO("server.worldserver", "                                 C O R E  /\\___/");
    TC_LOG_INFO("server.worldserver", "http://TrinityCore.org                    \\/__/\n");
    TC_LOG_INFO("server.worldserver", "Using configuration file %s.", configFile.c_str());
    TC_LOG_INFO("server.worldserver", "Using SSL version: %s (library: %s)", OPENSSL_VERSION_TEXT, SSLeay_version(SSLEAY_VERSION));
    TC_LOG_INFO("server.worldserver", "Using Boost version: %i.%i.%i", BOOST_VERSION / 100000, BOOST_VERSION / 100 % 1000, BOOST_VERSION % 100);

    OpenSSLCrypto::threadsSetup();

    // Seed the OpenSSL's PRNG here.
    // That way it won't auto-seed when calling BigNumber::SetRand and slow down the first world login
    BigNumber seed;
    seed.SetRand(16 * 8);

    /// worldserver PID file creation
    std::string pidFile = sConfigMgr->GetStringDefault("PidFile", "");
    if (!pidFile.empty())
    {
        if (uint32 pid = CreatePIDFile(pidFile))
            TC_LOG_INFO("server.worldserver", "Daemon PID: %u\n", pid);
        else
        {
            TC_LOG_ERROR("server.worldserver", "Cannot create PID file %s.\n", pidFile.c_str());
            return 1;
        }
    }

    // Set signal handlers (this must be done before starting io_service threads, because otherwise they would unblock and exit)
    boost::asio::signal_set signals(_ioService, SIGINT, SIGTERM);
#if PLATFORM == PLATFORM_WINDOWS
    signals.add(SIGBREAK);
#endif
    signals.async_wait(SignalHandler);

    // Start the Boost based thread pool
    int numThreads = sConfigMgr->GetIntDefault("ThreadPool", 1);
    std::vector<std::thread> threadPool;

    if (numThreads < 1)
        numThreads = 1;

    for (int i = 0; i < numThreads; ++i)
        threadPool.push_back(std::thread(boost::bind(&boost::asio::io_service::run, &_ioService)));

    // Set process priority according to configuration settings
    SetProcessPriority("server.worldserver");

    // Start the databases
    if (!StartDB())
    {
        ShutdownThreadPool(threadPool);
        return 1;
    }

    // Set server offline (not connectable)
    LoginDatabase.DirectPExecute("UPDATE realmlist SET flag = (flag & ~%u) | %u WHERE id = '%d'", REALM_FLAG_OFFLINE, REALM_FLAG_INVALID, realmID);

    // Initialize the World
    sWorld->SetInitialWorldSettings();

    // Launch CliRunnable thread
    std::thread* cliThread = nullptr;
#ifdef _WIN32
    if (sConfigMgr->GetBoolDefault("Console.Enable", true) && (m_ServiceStatus == -1)/* need disable console in service mode*/)
#else
    if (sConfigMgr->GetBoolDefault("Console.Enable", true))
#endif
    {
        cliThread = new std::thread(CliThread);
    }

    // Start the Remote Access port (acceptor) if enabled
    AsyncAcceptor* raAcceptor = nullptr;
    if (sConfigMgr->GetBoolDefault("Ra.Enable", false))
        raAcceptor = StartRaSocketAcceptor(_ioService);

    // Start soap serving thread if enabled
    std::thread* soapThread = nullptr;
    if (sConfigMgr->GetBoolDefault("SOAP.Enabled", false))
    {
        soapThread = new std::thread(TCSoapThread, sConfigMgr->GetStringDefault("SOAP.IP", "127.0.0.1"), uint16(sConfigMgr->GetIntDefault("SOAP.Port", 7878)));
    }

    // Launch the worldserver listener socket
    uint16 worldPort = uint16(sWorld->getIntConfig(CONFIG_PORT_WORLD));
    std::string worldListener = sConfigMgr->GetStringDefault("BindIP", "0.0.0.0");

    sWorldSocketMgr.StartNetwork(_ioService, worldListener, worldPort);

    // Set server online (allow connecting now)
    LoginDatabase.DirectPExecute("UPDATE realmlist SET flag = flag & ~%u, population = 0 WHERE id = '%u'", REALM_FLAG_INVALID, realmID);

    // Start the freeze check callback cycle in 5 seconds (cycle itself is 1 sec)
    if (int coreStuckTime = sConfigMgr->GetIntDefault("MaxCoreStuckTime", 0))
    {
        _maxCoreStuckTimeInMs = coreStuckTime * 1000;
        _freezeCheckTimer.expires_from_now(boost::posix_time::seconds(5));
        _freezeCheckTimer.async_wait(FreezeDetectorHandler);
        TC_LOG_INFO("server.worldserver", "Starting up anti-freeze thread (%u seconds max stuck time)...", coreStuckTime);
    }

    TC_LOG_INFO("server.worldserver", "%s (worldserver-daemon) ready...", _FULLVERSION);

    sScriptMgr->OnStartup();

    WorldUpdateLoop();

    // Shutdown starts here
    ShutdownThreadPool(threadPool);

    sScriptMgr->OnShutdown();

    sWorld->KickAll();                                       // save and kick all players
    sWorld->UpdateSessions(1);                             // real players unload required UpdateSessions call

    // unload battleground templates before different singletons destroyed
    sBattlegroundMgr->DeleteAllBattlegrounds();

    sWorldSocketMgr.StopNetwork();

    sInstanceSaveMgr->Unload();
    sMapMgr->UnloadAll();                     // unload all grids (including locked in memory)
    sObjectAccessor->UnloadAll();             // unload 'i_player2corpse' storage and remove from world
    sScriptMgr->Unload();
    sOutdoorPvPMgr->Die();

    // set server offline
    LoginDatabase.DirectPExecute("UPDATE realmlist SET flag = flag | %u WHERE id = '%d'", REALM_FLAG_OFFLINE, realmID);

    // Clean up threads if any
    if (soapThread != nullptr)
    {
        soapThread->join();
        delete soapThread;
    }

    if (raAcceptor != nullptr)
        delete raAcceptor;

    ///- Clean database before leaving
    ClearOnlineAccounts();

    StopDB();

    TC_LOG_INFO("server.worldserver", "Halting process...");

    if (cliThread != nullptr)
    {
#ifdef _WIN32
        CancelSynchronousIo(cliThread->native_handle());
#endif
        cliThread->join();
        delete cliThread;
    }

    OpenSSLCrypto::threadsCleanup();

    // 0 - normal shutdown
    // 1 - shutdown at error
    // 2 - restart command used, this code can be used by restarter for restart Trinityd

    return World::GetExitCode();
}

void ShutdownThreadPool(std::vector<std::thread>& threadPool)
{
    sScriptMgr->OnNetworkStop();

    _ioService.stop();

    for (auto& thread : threadPool)
    {
        thread.join();
    }
}

void WorldUpdateLoop()
{
    uint32 realCurrTime = 0;
    uint32 realPrevTime = getMSTime();

    uint32 prevSleepTime = 0;                               // used for balanced full tick time length near WORLD_SLEEP_CONST

    ///- While we have not World::m_stopEvent, update the world
    while (!World::IsStopped())
    {
        ++World::m_worldLoopCounter;
        realCurrTime = getMSTime();

        uint32 diff = getMSTimeDiff(realPrevTime, realCurrTime);

        sWorld->Update(diff);
        realPrevTime = realCurrTime;

        // diff (D0) include time of previous sleep (d0) + tick time (t0)
        // we want that next d1 + t1 == WORLD_SLEEP_CONST
        // we can't know next t1 and then can use (t0 + d1) == WORLD_SLEEP_CONST requirement
        // d1 = WORLD_SLEEP_CONST - t0 = WORLD_SLEEP_CONST - (D0 - d0) = WORLD_SLEEP_CONST + d0 - D0
        if (diff <= WORLD_SLEEP_CONST + prevSleepTime)
        {
            prevSleepTime = WORLD_SLEEP_CONST + prevSleepTime - diff;

            std::this_thread::sleep_for(std::chrono::milliseconds(prevSleepTime));
        }
        else
            prevSleepTime = 0;

#ifdef _WIN32
        if (m_ServiceStatus == 0)
            World::StopNow(SHUTDOWN_EXIT_CODE);

        while (m_ServiceStatus == 2)
            Sleep(1000);
#endif
    }
}

void SignalHandler(const boost::system::error_code& error, int /*signalNumber*/)
{
    if (!error)
        World::StopNow(SHUTDOWN_EXIT_CODE);
}

void FreezeDetectorHandler(const boost::system::error_code& error)
{
    if (!error)
    {
        uint32 curtime = getMSTime();

        uint32 worldLoopCounter = World::m_worldLoopCounter;
        if (_worldLoopCounter != worldLoopCounter)
        {
            _lastChangeMsTime = curtime;
            _worldLoopCounter = worldLoopCounter;
        }
        // possible freeze
        else if (getMSTimeDiff(_lastChangeMsTime, curtime) > _maxCoreStuckTimeInMs)
        {
            TC_LOG_ERROR("server.worldserver", "World Thread hangs, kicking out server!");
            ASSERT(false);
        }

        _freezeCheckTimer.expires_from_now(boost::posix_time::seconds(1));
        _freezeCheckTimer.async_wait(FreezeDetectorHandler);
    }
}

AsyncAcceptor* StartRaSocketAcceptor(boost::asio::io_service& ioService)
{
    uint16 raPort = uint16(sConfigMgr->GetIntDefault("Ra.Port", 3443));
    std::string raListener = sConfigMgr->GetStringDefault("Ra.IP", "0.0.0.0");

    AsyncAcceptor* acceptor = new AsyncAcceptor(ioService, raListener, raPort);
    acceptor->AsyncAccept<RASession>();
    return acceptor;
}

/// Initialize connection to the databases
bool StartDB()
{
    MySQL::Library_Init();

    std::string dbString;
    uint8 asyncThreads, synchThreads;

    dbString = sConfigMgr->GetStringDefault("WorldDatabaseInfo", "");
    if (dbString.empty())
    {
        TC_LOG_ERROR("server.worldserver", "World database not specified in configuration file");
        return false;
    }

    asyncThreads = uint8(sConfigMgr->GetIntDefault("WorldDatabase.WorkerThreads", 1));
    if (asyncThreads < 1 || asyncThreads > 32)
    {
        TC_LOG_ERROR("server.worldserver", "World database: invalid number of worker threads specified. "
            "Please pick a value between 1 and 32.");
        return false;
    }

    synchThreads = uint8(sConfigMgr->GetIntDefault("WorldDatabase.SynchThreads", 1));
    ///- Initialize the world database
    if (!WorldDatabase.Open(dbString, asyncThreads, synchThreads))
    {
        TC_LOG_ERROR("server.worldserver", "Cannot connect to world database %s", dbString.c_str());
        return false;
    }

    ///- Get character database info from configuration file
    dbString = sConfigMgr->GetStringDefault("CharacterDatabaseInfo", "");
    if (dbString.empty())
    {
        TC_LOG_ERROR("server.worldserver", "Character database not specified in configuration file");
        return false;
    }

    asyncThreads = uint8(sConfigMgr->GetIntDefault("CharacterDatabase.WorkerThreads", 1));
    if (asyncThreads < 1 || asyncThreads > 32)
    {
        TC_LOG_ERROR("server.worldserver", "Character database: invalid number of worker threads specified. "
            "Please pick a value between 1 and 32.");
        return false;
    }

    synchThreads = uint8(sConfigMgr->GetIntDefault("CharacterDatabase.SynchThreads", 2));

    ///- Initialize the Character database
    if (!CharacterDatabase.Open(dbString, asyncThreads, synchThreads))
    {
        TC_LOG_ERROR("server.worldserver", "Cannot connect to Character database %s", dbString.c_str());
        return false;
    }

    ///- Get login database info from configuration file
    dbString = sConfigMgr->GetStringDefault("LoginDatabaseInfo", "");
    if (dbString.empty())
    {
        TC_LOG_ERROR("server.worldserver", "Login database not specified in configuration file");
        return false;
    }

    asyncThreads = uint8(sConfigMgr->GetIntDefault("LoginDatabase.WorkerThreads", 1));
    if (asyncThreads < 1 || asyncThreads > 32)
    {
        TC_LOG_ERROR("server.worldserver", "Login database: invalid number of worker threads specified. "
            "Please pick a value between 1 and 32.");
        return false;
    }

    synchThreads = uint8(sConfigMgr->GetIntDefault("LoginDatabase.SynchThreads", 1));
    ///- Initialise the login database
    if (!LoginDatabase.Open(dbString, asyncThreads, synchThreads))
    {
        TC_LOG_ERROR("server.worldserver", "Cannot connect to login database %s", dbString.c_str());
        return false;
    }

    ///- Get the realm Id from the configuration file
    realmID = sConfigMgr->GetIntDefault("RealmID", 0);
    if (!realmID)
    {
        TC_LOG_ERROR("server.worldserver", "Realm ID not defined in configuration file");
        return false;
    }
    TC_LOG_INFO("server.worldserver", "Realm running as realm ID %d", realmID);

    ///- Clean the database before starting
    ClearOnlineAccounts();

    ///- Insert version info into DB
    WorldDatabase.PExecute("UPDATE version SET core_version = '%s', core_revision = '%s'", _FULLVERSION, _HASH);        // One-time query

    sWorld->LoadDBVersion();

    TC_LOG_INFO("server.worldserver", "Using World DB: %s", sWorld->GetDBVersion());
    return true;
}

void StopDB()
{
    CharacterDatabase.Close();
    WorldDatabase.Close();
    LoginDatabase.Close();

    MySQL::Library_End();
}

/// Clear 'online' status for all accounts with characters in this realm
void ClearOnlineAccounts()
{
    // Reset online status for all accounts with characters on the current realm
    LoginDatabase.DirectPExecute("UPDATE account SET online = 0 WHERE online > 0 AND id IN (SELECT acctid FROM realmcharacters WHERE realmid = %d)", realmID);

    // Reset online status for all characters
    CharacterDatabase.DirectExecute("UPDATE characters SET online = 0 WHERE online <> 0");

    // Battleground instance ids reset at server restart
    CharacterDatabase.DirectExecute("UPDATE character_battleground_data SET instanceId = 0");
}

/// @}

variables_map GetConsoleArguments(int argc, char** argv, std::string& configFile, std::string& configService)
{
    // Silences warning about configService not be used if the OS is not Windows
    (void)configService;

    options_description all("Allowed options");
    all.add_options()
        ("help,h", "print usage message")
        ("config,c", value<std::string>(&configFile)->default_value(_TRINITY_CORE_CONFIG), "use <arg> as configuration file")
        ;
#ifdef _WIN32
    options_description win("Windows platform specific options");
    win.add_options()
        ("service,s", value<std::string>(&configService)->default_value(""), "Windows service options: [install | uninstall]")
        ;

    all.add(win);
#endif
    variables_map vm;
    try
    {
        store(command_line_parser(argc, argv).options(all).allow_unregistered().run(), vm);
        notify(vm);
    }
    catch (std::exception& e) {
        std::cerr << e.what() << "\n";
    }

    if (vm.count("help")) {
        std::cout << all << "\n";
    }

    return vm;
}