// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "init.h"
#include "main.h"
#include "core.h"
#include "chainparams.h"
#include "txdb.h"
#include "walletdb.h"
#include "bitcoinrpc.h"
#include "net.h"
#include "util.h"
#include "ui_interface.h"
#include "checkpoints.h"
#include "softcheckpoint.h"
#include "twister.h"

#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/filesystem/convenience.hpp>
#include <boost/interprocess/sync/file_lock.hpp>
#include <boost/algorithm/string/predicate.hpp>
#ifdef HAVE_BOOST_LOCALE
  #include <boost/locale.hpp>
  #include <boost/locale/generator.hpp>
#endif
#include <openssl/crypto.h>

#ifndef WIN32
#include <signal.h>
#endif

#if defined(USE_SSE2)
#if !defined(MAC_OSX) && (defined(_M_IX86) || defined(__i386__) || defined(__i386))
#ifdef _MSC_VER
// MSVC 64bit is unable to use inline asm
#include <intrin.h>
#else
// GCC Linux or i686-w64-mingw32
#include <cpuid.h>
#endif
#endif
#endif

using namespace std;
using namespace boost;

CWallet* pwalletMain;
CClientUIInterface uiInterface;

#ifdef WIN32
// Win32 LevelDB doesn't use filedescriptors, and the ones used for
// accessing block files, don't count towards to fd_set size limit
// anyway.
#define MIN_CORE_FILEDESCRIPTORS 0
#else
#define MIN_CORE_FILEDESCRIPTORS 500
#endif

// Used to pass flags to the Bind() function
enum BindFlags {
    BF_NONE         = 0,
    BF_EXPLICIT     = (1U << 0),
    BF_REPORT_ERROR = (1U << 1)
};


//////////////////////////////////////////////////////////////////////////////
//
// Shutdown
//

//
// Thread management and startup/shutdown:
//
// The network-processing threads are all part of a thread group
// created by AppInit() or the Qt main() function.
//
// A clean exit happens when StartShutdown() or the SIGTERM
// signal handler sets fRequestShutdown, which triggers
// the DetectShutdownThread(), which interrupts the main thread group.
// DetectShutdownThread() then exits, which causes AppInit() to
// continue (it .joins the shutdown thread).
// Shutdown() is then
// called to clean up database connections, and stop other
// threads that should only be stopped after the main network-processing
// threads have exited.
//
// Note that if running -daemon the parent process returns from AppInit2
// before adding any threads to the threadGroup, so .join_all() returns
// immediately and the parent exits from main().
//
// Shutdown for Qt is very similar, only it uses a QTimer to detect
// fRequestShutdown getting set, and then does the normal Qt
// shutdown thing.
//

volatile bool fRequestShutdown = false;

void StartShutdown()
{
    fRequestShutdown = true;
}
bool ShutdownRequested()
{
    return fRequestShutdown;
}

static CCoinsViewDB *pcoinsdbview;

void Shutdown()
{
    static CCriticalSection cs_Shutdown;
    TRY_LOCK(cs_Shutdown, lockShutdown);
    if (!lockShutdown) return;

    RenameThread("bitcoin-shutoff");
    nTransactionsUpdated++;
    stopSessionTorrent();
    StopRPCThreads();
    ShutdownRPCMining();
    bitdb.Flush(false);
    GenerateBitcoins(false, NULL);
    StopNode();
    {
        LOCK(cs_main);
        if (pwalletMain)
            pwalletMain->SetBestChain(CBlockLocator(pindexBest));
        if (pblocktree)
            pblocktree->Flush();
        if (pcoinsTip)
            pcoinsTip->Flush();
        delete pcoinsTip; pcoinsTip = NULL;
        delete pcoinsdbview; pcoinsdbview = NULL;
        delete pblocktree; pblocktree = NULL;
    }
    bitdb.Flush(true);
    boost::filesystem::remove(GetPidFile());
    UnregisterAllWallets();
    delete pwalletMain;
}

//
// Signal handlers are very limited in what they are allowed to do, so:
//
void HandleSIGTERM(int)
{
    fRequestShutdown = true;
}

void HandleSIGHUP(int)
{
    fReopenDebugLog = true;
}

bool static InitError(const std::string &str)
{
    uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_ERROR);
    return false;
}

bool static InitWarning(const std::string &str)
{
    uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_WARNING);
    return true;
}

bool static Bind(const CService &addr, unsigned int flags) {
    if (!(flags & BF_EXPLICIT) && IsLimited(addr))
        return false;
    std::string strError;
    if (!BindListenPort(addr, strError)) {
        if (flags & BF_REPORT_ERROR)
            return InitError(strError);
        return false;
    }
    return true;
}

// Core-specific options shared between UI and daemon
std::string HelpMessage()
{
    string strUsage = _("Options:") + "\n";
    strUsage += "  -?                     " + _("This help message") + "\n";
    strUsage += "  -conf=<file>           " + _("Specify configuration file (default: ~/.twister/twister.conf)") + "\n";
    strUsage += "  -pid=<file>            " + _("Specify pid file (default: twisterd.pid)") + "\n";
    strUsage += "  -gen                   " + _("Generate coins (default: 0)") + "\n";
    strUsage += "  -datadir=<dir>         " + _("Specify data directory") + "\n";
    strUsage += "  -htmldir=<dir>         " + _("Specify HTML directory to serve (default: <data>/html)") + "\n";
    strUsage += "  -dbcache=<n>           " + _("Set database cache size in megabytes (default: 25)") + "\n";
    strUsage += "  -timeout=<n>           " + _("Specify connection timeout in milliseconds (default: 5000)") + "\n";
    strUsage += "  -proxy=<ip:port>       " + _("Connect through socks proxy") + "\n";
    strUsage += "  -socks=<n>             " + _("Select the version of socks proxy to use (4-5, default: 5)") + "\n";
    strUsage += "  -tor=<ip:port>         " + _("Use proxy to reach tor hidden services (default: same as -proxy)") + "\n";
    strUsage += "  -dns                   " + _("Allow DNS lookups for -addnode, -seednode and -connect") + "\n";
    strUsage += "  -port=<port>           " + _("Listen for connections on <port> (default: 28333 or testnet: 18333)") + "\n";
    strUsage += "  -maxconnections=<n>    " + _("Maintain at most <n> connections to peers (default: 125)") + "\n";
    strUsage += "  -addnode=<ip>          " + _("Add a node to connect to and attempt to keep the connection open") + "\n";
    strUsage += "  -connect=<ip>          " + _("Connect only to the specified node(s)") + "\n";
    strUsage += "  -seednode=<ip>         " + _("Connect to a node to retrieve peer addresses, and disconnect") + "\n";
    strUsage += "  -externalip=<ip>       " + _("Specify your own public address") + "\n";
    strUsage += "  -onlynet=<net>         " + _("Only connect to nodes in network <net> (IPv4, IPv6 or Tor)") + "\n";
    strUsage += "  -discover              " + _("Discover own IP address (default: 1 when listening and no -externalip)") + "\n";
    strUsage += "  -checkpoints           " + _("Only accept block chain matching built-in checkpoints (default: 1)") + "\n";
    strUsage += "  -listen                " + _("Accept connections from outside (default: 1 if no -proxy or -connect)") + "\n";
    strUsage += "  -bind=<addr>           " + _("Bind to given address and always listen on it. Use [host]:port notation for IPv6") + "\n";
    strUsage += "  -dnsseed               " + _("Find peers using DNS lookup (default: 1 unless -connect)") + "\n";
    strUsage += "  -banscore=<n>          " + _("Threshold for disconnecting misbehaving peers (default: 100)") + "\n";
    strUsage += "  -bantime=<n>           " + _("Number of seconds to keep misbehaving peers from reconnecting (default: 86400)") + "\n";
    strUsage += "  -maxreceivebuffer=<n>  " + _("Maximum per-connection receive buffer, <n>*1000 bytes (default: 5000)") + "\n";
    strUsage += "  -maxsendbuffer=<n>     " + _("Maximum per-connection send buffer, <n>*1000 bytes (default: 1000)") + "\n";
    strUsage += "  -upnp                  " + _("Use UPnP to map the listening port (default: 1 when listening)") + "\n";
    strUsage += "  -paytxfee=<amt>        " + _("Fee per KB to add to transactions you send") + "\n";
    if (fHaveGUI)
        strUsage += "  -server                " + _("Accept command line and JSON-RPC commands") + "\n";
#if !defined(WIN32)
    if (fHaveGUI)
        strUsage += "  -daemon                " + _("Run in the background as a daemon and accept commands") + "\n";
#endif
    strUsage += "  -testnet               " + _("Use the test network") + "\n";
    strUsage += "  -debug                 " + _("Output extra debugging information. Implies all other -debug* options") + "\n";
    strUsage += "  -debugnet              " + _("Output extra network debugging information") + "\n";
    strUsage += "  -logtimestamps         " + _("Prepend debug output with timestamp") + "\n";
    strUsage += "  -shrinkdebugfile       " + _("Shrink debug.log file on client startup (default: 1 when no -debug)") + "\n";
    strUsage += "  -printtoconsole        " + _("Send trace/debug info to console instead of debug.log file") + "\n";
    strUsage += "  -regtest               " + _("Enter regression test mode, which uses a special chain in which blocks can be "
                                                "solved instantly. This is intended for regression testing tools and app development.") + "\n";
#ifdef WIN32
    strUsage += "  -printtodebugger       " + _("Send trace/debug info to debugger") + "\n";
#endif
    strUsage += "  -rpcuser=<user>        " + _("Username for JSON-RPC connections") + "\n";
    strUsage += "  -rpcpassword=<pw>      " + _("Password for JSON-RPC connections") + "\n";
    strUsage += "  -rpcport=<port>        " + _("Listen for JSON-RPC connections on <port> (default: 28332 or testnet: 18332)") + "\n";
    strUsage += "  -rpcallowip=<ip>       " + _("Allow JSON-RPC connections from specified IP address") + "\n";
    if (!fHaveGUI)
        strUsage += "  -rpcconnect=<ip>       " + _("Send commands to node running on <ip> (default: 127.0.0.1)") + "\n";
    strUsage += "  -rpcthreads=<n>        " + _("Set the number of threads to service RPC calls (default: 10)") + "\n";
    strUsage += "  -blocknotify=<cmd>     " + _("Execute command when the best block changes (%s in cmd is replaced by block hash)") + "\n";
    strUsage += "  -walletnotify=<cmd>    " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n";
    strUsage += "  -alertnotify=<cmd>     " + _("Execute command when a relevant alert is received (%s in cmd is replaced by message)") + "\n";
    strUsage += "  -upgradewallet         " + _("Upgrade wallet to latest format") + "\n";
    strUsage += "  -keypool=<n>           " + _("Set key pool size to <n> (default: 100)") + "\n";
    strUsage += "  -rescan                " + _("Rescan the block chain for missing wallet transactions") + "\n";
    strUsage += "  -salvagewallet         " + _("Attempt to recover private keys from a corrupt twisterwallet.dat") + "\n";
    strUsage += "  -checkblocks=<n>       " + _("How many blocks to check at startup (default: 500, 0 = all)") + "\n";
    strUsage += "  -checklevel=<n>        " + _("How thorough the block verification is (0-4, default: 3)") + "\n";
    strUsage += "  -txindex               " + _("Maintain a full transaction index (default: 0)") + "\n";
    strUsage += "  -loadblock=<file>      " + _("Imports blocks from external blk000??.dat file") + "\n";
    strUsage += "  -reindex               " + _("Rebuild block chain index from current blk000??.dat files") + "\n";
    strUsage += "  -par=<n>               " + _("Set the number of script verification threads (up to 16, 0 = auto, <0 = leave that many cores free, default: 0)") + "\n";

    strUsage += "\n"; _("Block creation options:") + "\n";
    strUsage += "  -blockminsize=<n>      "   + _("Set minimum block size in bytes (default: 0)") + "\n";
    strUsage += "  -blockmaxsize=<n>      "   + _("Set maximum block size in bytes (default: 250000)") + "\n";
    strUsage += "  -blockprioritysize=<n> "   + _("Set maximum size of high-priority/low-fee transactions in bytes (default: 27000)") + "\n";

    strUsage += "\n"; _("SSL options: (see the Bitcoin Wiki for SSL setup instructions)") + "\n";
    strUsage += "  -rpcssl                                  " + _("Use OpenSSL (https) for JSON-RPC connections") + "\n";
    strUsage += "  -rpcsslcertificatechainfile=<file.cert>  " + _("Server certificate file (default: server.cert)") + "\n";
    strUsage += "  -rpcsslprivatekeyfile=<file.pem>         " + _("Server private key (default: server.pem)") + "\n";
    strUsage += "  -rpcsslciphers=<ciphers>                 " + _("Acceptable ciphers (default: TLSv1+HIGH:!SSLv2:!aNULL:!eNULL:!AH:!3DES:@STRENGTH)") + "\n";

    return strUsage;
}

struct CImportingNow
{
    CImportingNow() {
        assert(fImporting == false);
        fImporting = true;
    }

    ~CImportingNow() {
        assert(fImporting == true);
        fImporting = false;
    }
};

void ThreadImport(std::vector<boost::filesystem::path> vImportFiles)
{
    RenameThread("bitcoin-loadblk");

    // -reindex
    if (fReindex) {
        CImportingNow imp;
        int nFile = 0;
        while (true) {
            CDiskBlockPos pos(nFile, 0);
            FILE *file = OpenBlockFile(pos, true);
            if (!file)
                break;
            printf("Reindexing block file blk%05u.dat...\n", (unsigned int)nFile);
            LoadExternalBlockFile(file, &pos);
            nFile++;
        }
        pblocktree->WriteReindexing(false);
        fReindex = false;
        printf("Reindexing finished\n");
        // To avoid ending up in a situation without genesis block, re-try initializing (no-op if reindexing worked):
        InitBlockIndex();
    }

    // hardcoded $DATADIR/bootstrap.dat
    filesystem::path pathBootstrap = GetDataDir() / "bootstrap.dat";
    if (filesystem::exists(pathBootstrap)) {
        FILE *file = fopen(pathBootstrap.string().c_str(), "rb");
        if (file) {
            CImportingNow imp;
            filesystem::path pathBootstrapOld = GetDataDir() / "bootstrap.dat.old";
            printf("Importing bootstrap.dat...\n");
            LoadExternalBlockFile(file);
            RenameOver(pathBootstrap, pathBootstrapOld);
        }
    }

    // -loadblock=
    BOOST_FOREACH(boost::filesystem::path &path, vImportFiles) {
        FILE *file = fopen(path.string().c_str(), "rb");
        if (file) {
            CImportingNow imp;
            printf("Importing %s...\n", path.string().c_str());
            LoadExternalBlockFile(file);
        }
    }
}

/** Initialize bitcoin.
 *  @pre Parameters should be parsed and config file should be read.
 */
bool AppInit2(boost::thread_group& threadGroup)
{
    // ********************************************************* Step 1: setup
#ifdef _MSC_VER
    // Turn off Microsoft heap dump noise
    _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
    _CrtSetReportFile(_CRT_WARN, CreateFileA("NUL", GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0));
#endif
#if _MSC_VER >= 1400
    // Disable confusing "helpful" text message on abort, Ctrl-C
    _set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
#endif
#ifdef WIN32
    // Enable Data Execution Prevention (DEP)
    // Minimum supported OS versions: WinXP SP3, WinVista >= SP1, Win Server 2008
    // A failure is non-critical and needs no further attention!
#ifndef PROCESS_DEP_ENABLE
// We define this here, because GCCs winbase.h limits this to _WIN32_WINNT >= 0x0601 (Windows 7),
// which is not correct. Can be removed, when GCCs winbase.h is fixed!
#define PROCESS_DEP_ENABLE 0x00000001
#endif
    typedef BOOL (WINAPI *PSETPROCDEPPOL)(DWORD);
    PSETPROCDEPPOL setProcDEPPol = (PSETPROCDEPPOL)GetProcAddress(GetModuleHandleA("Kernel32.dll"), "SetProcessDEPPolicy");
    if (setProcDEPPol != NULL) setProcDEPPol(PROCESS_DEP_ENABLE);

    // Initialize Windows Sockets
    WSADATA wsadata;
    int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
    if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
    {
        return InitError(strprintf("Error: Winsock library failed to start (WSAStartup returned error %d)", ret));
    }
#endif
#ifndef WIN32
    umask(077);

    // Clean shutdown on SIGTERM
    struct sigaction sa;
    sa.sa_handler = HandleSIGTERM;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sigaction(SIGTERM, &sa, NULL);
    sigaction(SIGINT, &sa, NULL);

    // Reopen debug.log on SIGHUP
    struct sigaction sa_hup;
    sa_hup.sa_handler = HandleSIGHUP;
    sigemptyset(&sa_hup.sa_mask);
    sa_hup.sa_flags = 0;
    sigaction(SIGHUP, &sa_hup, NULL);
#endif

#if defined(USE_SSE2)
    unsigned int cpuid_edx=0;
#if !defined(MAC_OSX) && (defined(_M_IX86) || defined(__i386__) || defined(__i386))
    // 32bit x86 Linux or Windows, detect cpuid features
#if defined(_MSC_VER)
    // MSVC
    int x86cpuid[4];
    __cpuid(x86cpuid, 1);
    cpuid_edx = (unsigned int)buffer[3];
#else
    // Linux or i686-w64-mingw32 (gcc-4.6.3)
    unsigned int eax, ebx, ecx;
    __get_cpuid(1, &eax, &ebx, &ecx, &cpuid_edx);
#endif
#endif
#endif
#ifdef HAVE_BOOST_LOCALE
    std::locale::global(boost::locale::generator().generate(""));
#endif

    // ********************************************************* Step 2: parameter interactions

    Checkpoints::fEnabled = GetBoolArg("-checkpoints", true);
    SoftCheckpoints::fEnabled = GetBoolArg("-softcheckpoints", true);
    if (!SelectParamsFromCommandLine()) {
        return InitError("Invalid combination of -testnet and -regtest.");
    }

    if (mapArgs.count("-bind")) {
        // when specifying an explicit binding address, you want to listen on it
        // even when -connect or -proxy is specified
        SoftSetBoolArg("-listen", true);
    }

    if (mapArgs.count("-connect") && mapMultiArgs["-connect"].size() > 0) {
        // when only connecting to trusted nodes, do not seed via DNS, or listen by default
        SoftSetBoolArg("-dnsseed", false);
        SoftSetBoolArg("-listen", false);
    }

    if (mapArgs.count("-proxy")) {
        // to protect privacy, do not listen by default if a proxy server is specified
        SoftSetBoolArg("-listen", false);
    }
    
    if (mapArgs.count("-proxy") || mapArgs.count("-tor")) {
        SoftSetBoolArg("-dhtproxy", true);
    }
    
    if (!GetBoolArg("-listen", true)) {
        // do not map ports or try to retrieve public IP when not listening (pointless)
        SoftSetBoolArg("-upnp", false);
        SoftSetBoolArg("-discover", false);
    }

    if (mapArgs.count("-externalip")) {
        // if an explicit public IP is specified, do not try to find others
        SoftSetBoolArg("-discover", false);
    }

    if (GetBoolArg("-salvagewallet", false)) {
        // Rewrite just private keys: rescan to find transactions
        SoftSetBoolArg("-rescan", true);
    }

    // Make sure enough file descriptors are available
    int nBind = std::max((int)mapArgs.count("-bind"), 1);
    nMaxConnections = GetArg("-maxconnections", 125);
    nMaxConnections = std::max(std::min(nMaxConnections, (int)(FD_SETSIZE - nBind - MIN_CORE_FILEDESCRIPTORS)), 0);
    int nFD = RaiseFileDescriptorLimit(nMaxConnections + MIN_CORE_FILEDESCRIPTORS);
    if (nFD < MIN_CORE_FILEDESCRIPTORS)
        return InitError(_("Not enough file descriptors available."));
    if (nFD - MIN_CORE_FILEDESCRIPTORS < nMaxConnections)
        nMaxConnections = nFD - MIN_CORE_FILEDESCRIPTORS;

    // ********************************************************* Step 3: parameter-to-internal-flags

    fDebug = GetBoolArg("-debug", false);
    fBenchmark = GetBoolArg("-benchmark", false);

    // -par=0 means autodetect, but nScriptCheckThreads==0 means no concurrency
    nScriptCheckThreads = GetArg("-par", 0);
    if (nScriptCheckThreads <= 0)
        nScriptCheckThreads += boost::thread::hardware_concurrency();
    if (nScriptCheckThreads <= 1)
        nScriptCheckThreads = 0;
    else if (nScriptCheckThreads > MAX_SCRIPTCHECK_THREADS)
        nScriptCheckThreads = MAX_SCRIPTCHECK_THREADS;

    // -debug implies fDebug*
    if (fDebug)
        fDebugNet = true;
    else
        fDebugNet = GetBoolArg("-debugnet", false);

    if (fDaemon)
        fServer = true;
    else
        fServer = GetBoolArg("-server", false);

    /* force fServer when running without GUI */
    if (!fHaveGUI)
        fServer = true;
    fPrintToConsole = GetBoolArg("-printtoconsole", false);
    fPrintToDebugger = GetBoolArg("-printtodebugger", false);
    fLogTimestamps = GetBoolArg("-logtimestamps", false);

    if (mapArgs.count("-timeout"))
    {
        int nNewTimeout = GetArg("-timeout", 5000);
        if (nNewTimeout > 0 && nNewTimeout < 600000)
            nConnectTimeout = nNewTimeout;
    }

    // Continue to put "/P2SH/" in the coinbase to monitor
    // BIP16 support.
    // This can be removed eventually...
    const char* pszP2SH = "/P2SH/";
    COINBASE_FLAGS << std::vector<unsigned char>(pszP2SH, pszP2SH+strlen(pszP2SH));

    // ********************************************************* Step 4: application initialization: dir lock, daemonize, pidfile, debug log

    std::string strDataDir = GetDataDir().string();

    // Make sure only a single Bitcoin process is using the data directory.
    boost::filesystem::path pathLockFile = GetDataDir() / ".lock";
    FILE* file = fopen(pathLockFile.string().c_str(), "a"); // empty lock file; created if it doesn't exist.
    if (file) fclose(file);
    static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
    if (!lock.try_lock())
        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Twister is probably already running."), strDataDir.c_str()));

    if (GetBoolArg("-shrinkdebugfile", !fDebug))
        ShrinkDebugFile();
    printf("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
    printf("Twister version %s (%s)\n", FormatFullVersion().c_str(), CLIENT_DATE.c_str());
    printf("Using OpenSSL version %s\n", SSLeay_version(SSLEAY_VERSION));
    if (!fLogTimestamps)
        printf("Startup time: %s\n", DateTimeStrFormat("%Y-%m-%d %H:%M:%S", GetTime()).c_str());
    printf("Default data directory %s\n", GetDefaultDataDir().string().c_str());
    printf("Using data directory %s\n", strDataDir.c_str());
    printf("Using at most %i connections (%i file descriptors available)\n", nMaxConnections, nFD);
    std::ostringstream strErrors;

    if (fDaemon)
        fprintf(stdout, "Twister server starting\n");

    int64 nStart;

    // ********************************************************* Step 5: verify wallet database integrity

    uiInterface.InitMessage(_("Verifying wallet..."));

    if (!bitdb.Open(GetDataDir()))
    {
        // try moving the database env out of the way
        boost::filesystem::path pathDatabase = GetDataDir() / "database";
        boost::filesystem::path pathDatabaseBak = GetDataDir() / strprintf("database.%"PRI64d".bak", GetTime());
        try {
            boost::filesystem::rename(pathDatabase, pathDatabaseBak);
            printf("Moved old %s to %s. Retrying.\n", pathDatabase.string().c_str(), pathDatabaseBak.string().c_str());
        } catch(boost::filesystem::filesystem_error &error) {
             // failure is ok (well, not really, but it's not worse than what we started with)
        }

        // try again
        if (!bitdb.Open(GetDataDir())) {
            // if it still fails, it probably means we can't even create the database env
            string msg = strprintf(_("Error initializing wallet database environment %s!"), strDataDir.c_str());
            return InitError(msg);
        }
    }

    if (GetBoolArg("-salvagewallet", false))
    {
        // Recover readable keypairs:
        if (!CWalletDB::Recover(bitdb, "twisterwallet.dat", true))
            return false;
    }

    if (filesystem::exists(GetDataDir() / "twisterwallet.dat"))
    {
        CDBEnv::VerifyResult r = bitdb.Verify("twisterwallet.dat", CWalletDB::Recover);
        if (r == CDBEnv::RECOVER_OK)
        {
            string msg = strprintf(_("Warning: twisterwallet.dat corrupt, data salvaged!"
                                     " Original twisterwallet.dat saved as wallet.{timestamp}.bak in %s; if"
                                     " your balance or transactions are incorrect you should"
                                     " restore from a backup."), strDataDir.c_str());
            InitWarning(msg);
        }
        if (r == CDBEnv::RECOVER_FAIL)
            return InitError(_("twisterwallet.dat corrupt, salvage failed"));
    }

    // ********************************************************* Step 6: network initialization

    RegisterNodeSignals(GetNodeSignals());

    int nSocksVersion = GetArg("-socks", 5);
    if (nSocksVersion != 4 && nSocksVersion != 5)
        return InitError(strprintf(_("Unknown -socks proxy version requested: %i"), nSocksVersion));

    if (mapArgs.count("-onlynet")) {
        std::set<enum Network> nets;
        BOOST_FOREACH(std::string snet, mapMultiArgs["-onlynet"]) {
            enum Network net = ParseNetwork(snet);
            if (net == NET_UNROUTABLE)
                return InitError(strprintf(_("Unknown network specified in -onlynet: '%s'"), snet.c_str()));
            nets.insert(net);
        }
        for (int n = 0; n < NET_MAX; n++) {
            enum Network net = (enum Network)n;
            if (!nets.count(net))
                SetLimited(net);
        }
    }
#if defined(USE_IPV6)
#if ! USE_IPV6
    else
        SetLimited(NET_IPV6);
#endif
#endif

    CService addrProxy;
    bool fProxy = false;
    if (mapArgs.count("-proxy")) {
        addrProxy = CService(mapArgs["-proxy"], 9050);
        if (!addrProxy.IsValid())
            return InitError(strprintf(_("Invalid -proxy address: '%s'"), mapArgs["-proxy"].c_str()));

        if (!IsLimited(NET_IPV4)) {
            SetProxy(NET_IPV4, addrProxy, nSocksVersion);
            SetReachable(NET_IPV4);
        }
        if (nSocksVersion > 4) {
#ifdef USE_IPV6
            if (!IsLimited(NET_IPV6))
                SetProxy(NET_IPV6, addrProxy, nSocksVersion);
#endif
            SetNameProxy(addrProxy, nSocksVersion);
        }
        fProxy = true;
    }

    // -tor can override normal proxy, -notor disables tor entirely
    if (!(mapArgs.count("-tor") && mapArgs["-tor"] == "0") && (fProxy || mapArgs.count("-tor"))) {
        CService addrOnion;
        if (!mapArgs.count("-tor"))
            addrOnion = addrProxy;
        else
            addrOnion = CService(mapArgs["-tor"], 9050);
        if (!addrOnion.IsValid())
            return InitError(strprintf(_("Invalid -tor address: '%s'"), mapArgs["-tor"].c_str()));
        SetProxy(NET_TOR, addrOnion, 5);
        SetReachable(NET_TOR);
    }

    // see Step 2: parameter interactions for more information about these
    fNoListen = !GetBoolArg("-listen", true);
    fDiscover = GetBoolArg("-discover", true);
    fNameLookup = GetBoolArg("-dns", true);

    bool fBound = false;
    if (!fNoListen) {
        if (mapArgs.count("-bind")) {
            BOOST_FOREACH(std::string strBind, mapMultiArgs["-bind"]) {
                CService addrBind;
                if (!Lookup(strBind.c_str(), addrBind, GetListenPort(), false))
                    return InitError(strprintf(_("Cannot resolve -bind address: '%s'"), strBind.c_str()));
                fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR));
            }
        }
        else {
            struct in_addr inaddr_any;
            inaddr_any.s_addr = INADDR_ANY;
#ifdef USE_IPV6
            fBound |= Bind(CService(in6addr_any, GetListenPort()), BF_NONE);
#endif
            fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE);
        }
        if (!fBound)
            return InitError(_("Failed to listen on any port. Use -listen=0 if you want this."));
    }

    if (mapArgs.count("-externalip")) {
        BOOST_FOREACH(string strAddr, mapMultiArgs["-externalip"]) {
            CService addrLocal(strAddr, GetListenPort(), fNameLookup);
            if (!addrLocal.IsValid())
                return InitError(strprintf(_("Cannot resolve -externalip address: '%s'"), strAddr.c_str()));
            AddLocal(CService(strAddr, GetListenPort(), fNameLookup), LOCAL_MANUAL);
        }
    }

    BOOST_FOREACH(string strDest, mapMultiArgs["-seednode"])
        AddOneShot(strDest);

    // ********************************************************* Step 7: load block chain
#if defined(USE_SSE2)
    scrypt_detect_sse2(cpuid_edx);
#endif

    fReindex = GetBoolArg("-reindex", false);

    // Upgrading to 0.8; hard-link the old blknnnn.dat files into /blocks/
    filesystem::path blocksDir = GetDataDir() / "blocks";
    if (!filesystem::exists(blocksDir))
    {
        filesystem::create_directories(blocksDir);
        bool linked = false;
        for (unsigned int i = 1; i < 10000; i++) {
            filesystem::path source = GetDataDir() / strprintf("blk%04u.dat", i);
            if (!filesystem::exists(source)) break;
            filesystem::path dest = blocksDir / strprintf("blk%05u.dat", i-1);
            try {
                filesystem::create_hard_link(source, dest);
                printf("Hardlinked %s -> %s\n", source.string().c_str(), dest.string().c_str());
                linked = true;
            } catch (filesystem::filesystem_error & e) {
                // Note: hardlink creation failing is not a disaster, it just means
                // blocks will get re-downloaded from peers.
                printf("Error hardlinking blk%04u.dat : %s\n", i, e.what());
                break;
            }
        }
        if (linked)
        {
            fReindex = true;
        }
    }

    // cache size calculations
    size_t nTotalCache = GetArg("-dbcache", 25) << 20;
    if (nTotalCache < (1 << 22))
        nTotalCache = (1 << 22); // total cache cannot be less than 4 MiB
    size_t nBlockTreeDBCache = nTotalCache / 8;
    if (nBlockTreeDBCache > (1 << 21) && !GetBoolArg("-txindex", false))
        nBlockTreeDBCache = (1 << 21); // block tree db cache shouldn't be larger than 2 MiB
    nTotalCache -= nBlockTreeDBCache;
    size_t nCoinDBCache = nTotalCache / 2; // use half of the remaining cache for coindb cache
    nTotalCache -= nCoinDBCache;
    nCoinCacheSize = nTotalCache / 300; // coins in memory require around 300 bytes

    bool fLoaded = false;
    while (!fLoaded) {
        bool fReset = fReindex;
        std::string strLoadError;

        uiInterface.InitMessage(_("Loading block index..."));

        nStart = GetTimeMillis();
        do {
            try {
                UnloadBlockIndex();
                delete pcoinsTip;
                delete pcoinsdbview;
                delete pblocktree;

                pblocktree = new CBlockTreeDB(nBlockTreeDBCache, false, fReindex);
                pcoinsdbview = new CCoinsViewDB(nCoinDBCache, false, fReindex);
                pcoinsTip = new CCoinsViewCache(*pcoinsdbview);

                if (fReindex)
                    pblocktree->WriteReindexing(true);

                if (!LoadBlockIndex()) {
                    strLoadError = _("Error loading block database");
                    break;
                }

                // If the loaded chain has a wrong genesis, bail out immediately
                // (we're likely using a testnet datadir, or the other way around).
                if (!mapBlockIndex.empty() && pindexGenesisBlock == NULL)
                    return InitError(_("Incorrect or no genesis block found. Wrong datadir for network?"));

                // Initialize the block index (no-op if non-empty database was already loaded)
                if (!InitBlockIndex()) {
                    strLoadError = _("Error initializing block database");
                    break;
                }

                uiInterface.InitMessage(_("Verifying blocks..."));
                if (!VerifyDB(GetArg("-checklevel", 3),
                              GetArg( "-checkblocks", 500))) {
                    strLoadError = _("Corrupted block database detected");
                    break;
                }

                if( mapBlockIndex.size() > 1000 && nBestHeight <= 0 ) {
                    strLoadError = _("mapBlockIndex detected but nBestHeight still zero, trying to repair (reindex)");
                    break;
                }
            } catch(std::exception &e) {
                strLoadError = _("Error opening block database");
                break;
            }

            fLoaded = true;
        } while(false);

        if (!fLoaded) {
            // first suggest a reindex
            if (!fReset) {
                /*bool fRet =*/ uiInterface.ThreadSafeMessageBox(
                    strLoadError + ".\n\n" + _("Do you want to rebuild the block database now? (assuming YES)"),
                    "", CClientUIInterface::MSG_ERROR | CClientUIInterface::BTN_ABORT);
                if (true /* [MF] fRet*/) {
                    fReindex = true;
                    fRequestShutdown = false;
                } else {
                    return false;
                }
            } else {
                return InitError(strLoadError);
            }
        }
    }

    // as LoadBlockIndex can take several minutes, it's possible the user
    // requested to kill bitcoin-qt during the last operation. If so, exit.
    // As the program has not fully started yet, Shutdown() is possibly overkill.
    if (fRequestShutdown)
    {
        printf("Shutdown requested. Exiting.\n");
        return false;
    }
    printf(" block index %15"PRI64d"ms\n", GetTimeMillis() - nStart);

    if (GetBoolArg("-printblockindex", false) || GetBoolArg("-printblocktree", false))
    {
        PrintBlockTree();
        return false;
    }

    if (mapArgs.count("-printblock"))
    {
        string strMatch = mapArgs["-printblock"];
        int nFound = 0;
        for (map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.begin(); mi != mapBlockIndex.end(); ++mi)
        {
            uint256 hash = (*mi).first;
            if (strncmp(hash.ToString().c_str(), strMatch.c_str(), strMatch.size()) == 0)
            {
                CBlockIndex* pindex = (*mi).second;
                CBlock block;
                ReadBlockFromDisk(block, pindex);
                block.BuildMerkleTree();
                block.print();
                printf("\n");
                nFound++;
            }
        }
        if (nFound == 0)
            printf("No blocks matching %s were found\n", strMatch.c_str());
        return false;
    }

    // ********************************************************* Step 8: load wallet

    uiInterface.InitMessage(_("Loading wallet..."));

    nStart = GetTimeMillis();
    bool fFirstRun = true;
    pwalletMain = new CWallet("twisterwallet.dat");
    DBErrors nLoadWalletRet = pwalletMain->LoadWallet(fFirstRun);
    if (nLoadWalletRet != DB_LOAD_OK)
    {
        if (nLoadWalletRet == DB_CORRUPT)
            strErrors << _("Error loading twisterwallet.dat: Wallet corrupted") << "\n";
        else if (nLoadWalletRet == DB_NONCRITICAL_ERROR)
        {
            string msg(_("Warning: error reading twisterwallet.dat! All keys read correctly, but transaction data"
                         " or address book entries might be missing or incorrect."));
            InitWarning(msg);
        }
        else if (nLoadWalletRet == DB_TOO_NEW)
            strErrors << _("Error loading twisterwallet.dat: Wallet requires newer version of Bitcoin") << "\n";
        else if (nLoadWalletRet == DB_NEED_REWRITE)
        {
            strErrors << _("Wallet needed to be rewritten: restart Twister to complete") << "\n";
            printf("%s", strErrors.str().c_str());
            return InitError(strErrors.str());
        }
        else
            strErrors << _("Error loading twisterwallet.dat") << "\n";
    }

    if (GetBoolArg("-upgradewallet", fFirstRun))
    {
        int nMaxVersion = GetArg("-upgradewallet", 0);
        if (nMaxVersion == 0) // the -upgradewallet without argument case
        {
            printf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
            nMaxVersion = CLIENT_VERSION;
            pwalletMain->SetMinVersion(FEATURE_LATEST); // permanently upgrade the wallet immediately
        }
        else
            printf("Allowing wallet upgrade up to %i\n", nMaxVersion);
        if (nMaxVersion < pwalletMain->GetVersion())
            strErrors << _("Cannot downgrade wallet") << "\n";
        pwalletMain->SetMaxVersion(nMaxVersion);
    }

    if (fFirstRun)
    {
        // Create new keyUser and set as default key
        RandAddSeedPerfmon();

        /* [MF] FIXME: require user on initialization?
        CPubKey newDefaultKey;
        if (pwalletMain->GetKeyFromPool(newDefaultKey, false)) {
            pwalletMain->SetDefaultKey(newDefaultKey);
            if (!pwalletMain->SetAddressBookName(pwalletMain->vchDefaultKey.GetID(), ""))
                strErrors << _("Cannot write default address") << "\n";
        }
        */

        pwalletMain->SetBestChain(CBlockLocator(pindexBest));
    }

    printf("%s", strErrors.str().c_str());
    printf(" wallet      %15"PRI64d"ms\n", GetTimeMillis() - nStart);

    RegisterWallet(pwalletMain);

    CBlockIndex *pindexRescan = pindexBest;
    if (GetBoolArg("-rescan", false))
        pindexRescan = pindexGenesisBlock;
    else
    {
        CWalletDB walletdb("twisterwallet.dat");
        CBlockLocator locator;
        if (walletdb.ReadBestBlock(locator))
            pindexRescan = locator.GetBlockIndex();
        else
            pindexRescan = pindexGenesisBlock;
    }
    if (pindexBest && pindexBest != pindexRescan)
    {
        uiInterface.InitMessage(_("Rescanning..."));
        printf("Rescanning last %i blocks (from block %i)...\n", pindexBest->nHeight - pindexRescan->nHeight, pindexRescan->nHeight);
        nStart = GetTimeMillis();
        pwalletMain->ScanForWalletTransactions(pindexRescan, true);
        printf(" rescan      %15"PRI64d"ms\n", GetTimeMillis() - nStart);
        pwalletMain->SetBestChain(CBlockLocator(pindexBest));
        nWalletDBUpdated++;
    }

    // ********************************************************* Step 9: import blocks

    // scan for better chains in the block chain database, that are not yet connected in the active best chain
    CValidationState state;
    if (!ConnectBestBlock(state)) {
        // try again before giving up
        if (!ConnectBestBlock(state))
            strErrors << "Failed to connect best block (try -reindex)";
    }

    std::vector<boost::filesystem::path> vImportFiles;
    if (mapArgs.count("-loadblock"))
    {
        BOOST_FOREACH(string strFile, mapMultiArgs["-loadblock"])
            vImportFiles.push_back(strFile);
    }
    threadGroup.create_thread(boost::bind(&ThreadImport, vImportFiles));

    // ********************************************************* Step 10: load peers

    uiInterface.InitMessage(_("Loading addresses..."));

    nStart = GetTimeMillis();

    {
        CAddrDB adb;
        if (!adb.Read(addrman))
            printf("Invalid or missing peers.dat; recreating\n");
    }

    printf("Loaded %i addresses from peers.dat  %"PRI64d"ms\n",
           addrman.size(), GetTimeMillis() - nStart);

    // ********************************************************* Step 11: start node

    if (!CheckDiskSpace())
        return false;

    if (!strErrors.str().empty())
        return InitError(strErrors.str());

    RandAddSeedPerfmon();

    //// debug print
    printf("mapBlockIndex.size() = %"PRIszu"\n",   mapBlockIndex.size());
    printf("nBestHeight = %d\n",                   nBestHeight);
    printf("setKeyPool.size() = %"PRIszu"\n",      pwalletMain->setKeyPool.size());
    printf("mapWallet.size() = %"PRIszu"\n",       pwalletMain->mapWallet.size());
    printf("mapAddressBook.size() = %"PRIszu"\n",  pwalletMain->mapAddressBook.size());

    StartNode(threadGroup);

    // InitRPCMining is needed here so getwork/getblocktemplate in the GUI debug console works properly.
    InitRPCMining();
    if (fServer)
        StartRPCThreads();

    // Generate coins in the background
    GenerateBitcoins(GetBoolArg("-gen", false), pwalletMain);

    // ********************************************************* Step 12: finished

    uiInterface.InitMessage(_("Done loading"));

     // Add wallet transactions that aren't already in a block to mapTransactions
    pwalletMain->ReacceptWalletTransactions();

    // Run a thread to flush wallet periodically
    threadGroup.create_thread(boost::bind(&ThreadFlushWalletDB, boost::ref(pwalletMain->strWalletFile)));

    // Start libtorrent + dht
    startSessionTorrent(threadGroup);

    return !fRequestShutdown;
}