#include "clientmodel.h"
#include "guiconstants.h"
#include "optionsmodel.h"
#include "addresstablemodel.h"
#include "transactiontablemodel.h"

#include "alert.h"
#include "main.h"
#include "ui_interface.h"

#include <QDateTime>
#include <QTimer>

static const int64_t nClientStartupTime = GetTime();

ClientModel::ClientModel(OptionsModel *optionsModel, QObject *parent) :
    QObject(parent), optionsModel(optionsModel),
    cachedNumBlocks(0), cachedNumBlocksOfPeers(0), cachedNumConnections(0), pollTimer(0)
{
    numBlocksAtStartup = -1;

    pollTimer = new QTimer(this);
    pollTimer->setInterval(MODEL_UPDATE_DELAY);
    pollTimer->start();
    connect(pollTimer, SIGNAL(timeout()), this, SLOT(updateTimer()));

    subscribeToCoreSignals();
}

ClientModel::~ClientModel()
{
    unsubscribeFromCoreSignals();
}

int ClientModel::getNumConnections() const
{
    // Use TRY_LOCK to avoid blocking the UI thread when the network
    // thread holds cs_vNodes (e.g. during DNS resolution or connections).
    // Return the cached value if the lock is busy.
    TRY_LOCK(cs_vNodes, lockNodes);
    if (lockNodes) {
        cachedNumConnections = vNodes.size();
    }
    return cachedNumConnections;
}

int ClientModel::getNumBlocks() const
{
    return nBestHeight;
}

int ClientModel::getNumBlocksAtStartup()
{
    if (numBlocksAtStartup == -1) numBlocksAtStartup = getNumBlocks();
    return numBlocksAtStartup;
}

QDateTime ClientModel::getLastBlockDate() const
{
    if (pindexBest)
        return QDateTime::fromTime_t(pindexBest->GetBlockTime());
    else
        return QDateTime::fromTime_t(1393221600); // Genesis block's time
}

void ClientModel::updateTimer()
{
    // Some quantities (such as number of blocks) change so fast that we don't want to be notified for each change.
    // Periodically check and update with a timer.
    int newNumBlocks = getNumBlocks();
    int newNumBlocksOfPeers = getNumBlocksOfPeers();

    // Always emit when values change or during IBD.
    // Also emit every ~30 seconds even when idle so setNumBlocks() can
    // re-evaluate sync status (e.g. when a new block arrives after a long gap).
    static int64_t nLastEmit = 0;
    int64_t nNow = GetTime();
    bool fChanged = (cachedNumBlocks != newNumBlocks || cachedNumBlocksOfPeers != newNumBlocksOfPeers);
    bool fCatchingUp = (newNumBlocks < newNumBlocksOfPeers);
    bool fPeriodicRefresh = (nNow - nLastEmit >= 30);

    if(fChanged || fCatchingUp || fPeriodicRefresh)
    {
        cachedNumBlocks = newNumBlocks;
        cachedNumBlocksOfPeers = newNumBlocksOfPeers;
        nLastEmit = nNow;

        emit numBlocksChanged(newNumBlocks, newNumBlocksOfPeers);
    }
}

void ClientModel::updateNumConnections(int numConnections)
{
    emit numConnectionsChanged(numConnections);
}

void ClientModel::updateAlert(const QString &hash, int status)
{
    // Show error message notification for new alert
    if(status == CT_NEW)
    {
        uint256 hash_256;
        hash_256.SetHex(hash.toStdString());
        CAlert alert = CAlert::getAlertByHash(hash_256);
        if(!alert.IsNull())
        {
            emit error(tr("Network Alert"), QString::fromStdString(alert.strStatusBar), false);
        }
    }

    // Emit a numBlocksChanged when the status message changes,
    // so that the view recomputes and updates the status bar.
    emit numBlocksChanged(getNumBlocks(), getNumBlocksOfPeers());
}

double ClientModel::GetDifficulty() const
{
    // Floating point number that is a multiple of the minimum difficulty,
    // minimum difficulty = 1.0.

    if (pindexBest == NULL)
        return 1.0;
    int nShift = (pindexBest->nBits >> 24) & 0xff;

    double dDiff =
        (double)0x0000ffff / (double)(pindexBest->nBits & 0x00ffffff);

    while (nShift < 29)
    {
        dDiff *= 256.0;
        nShift++;
    }
    while (nShift > 29)
    {
        dDiff /= 256.0;
        nShift--;
    }

    return dDiff;
}

bool ClientModel::isTestNet() const
{
    return fTestNet;
}

bool ClientModel::inInitialBlockDownload() const
{
    return IsInitialBlockDownload();
}

int ClientModel::getNumBlocksOfPeers() const
{
    return GetNumBlocksOfPeers();
}

QString ClientModel::getStatusBarWarnings() const
{
    return QString::fromStdString(GetWarnings("statusbar"));
}

OptionsModel *ClientModel::getOptionsModel()
{
    return optionsModel;
}

QString ClientModel::formatFullVersion() const
{
    return QString::fromStdString(FormatFullVersion());
}

QString ClientModel::formatBuildDate() const
{
    return QString::fromStdString(CLIENT_DATE);
}

QString ClientModel::clientName() const
{
    return QString::fromStdString(CLIENT_NAME);
}

QString ClientModel::formatClientStartupTime() const
{
    return QDateTime::fromTime_t(nClientStartupTime).toString();
}

// Handlers for core signals
static void NotifyBlocksChanged(ClientModel *clientmodel)
{
    // This notification is too frequent. Don't trigger a signal.
    // Don't remove it, though, as it might be useful later.
}

static void NotifyNumConnectionsChanged(ClientModel *clientmodel, int newNumConnections)
{
    // Don't queue UI updates during shutdown - ClientModel may be destroyed
    // before Qt processes the queued invocation, causing use-after-free.
    if (fShutdown) return;
    QMetaObject::invokeMethod(clientmodel, "updateNumConnections", Qt::QueuedConnection,
                              Q_ARG(int, newNumConnections));
}

static void NotifyAlertChanged(ClientModel *clientmodel, const uint256 &hash, ChangeType status)
{
    if (fShutdown) return;
    OutputDebugStringF("NotifyAlertChanged %s status=%i\n", hash.GetHex().c_str(), status);
    QMetaObject::invokeMethod(clientmodel, "updateAlert", Qt::QueuedConnection,
                              Q_ARG(QString, QString::fromStdString(hash.GetHex())),
                              Q_ARG(int, status));
}

void ClientModel::subscribeToCoreSignals()
{
    // Connect signals to client
    uiInterface.NotifyBlocksChanged.connect(boost::bind(NotifyBlocksChanged, this));
    uiInterface.NotifyNumConnectionsChanged.connect(boost::bind(NotifyNumConnectionsChanged, this, _1));
    uiInterface.NotifyAlertChanged.connect(boost::bind(NotifyAlertChanged, this, _1, _2));
}

void ClientModel::unsubscribeFromCoreSignals()
{
    // Disconnect signals from client
    uiInterface.NotifyBlocksChanged.disconnect(boost::bind(NotifyBlocksChanged, this));
    uiInterface.NotifyNumConnectionsChanged.disconnect(boost::bind(NotifyNumConnectionsChanged, this, _1));
    uiInterface.NotifyAlertChanged.disconnect(boost::bind(NotifyAlertChanged, this, _1, _2));
}