/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
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** This file is part of the demonstration applications of the Qt Toolkit.
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** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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** rights.  These rights are described in the Nokia Qt LGPL Exception
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****************************************************************************/

#include "history.h"

#include "autosaver.h"
#include "browserapplication.h"

#include <QtCore/QBuffer>
#include <QtCore/QDir>
#include <QtCore/QFile>
#include <QtCore/QFileInfo>
#include <QtCore/QSettings>
#include <QtCore/QTemporaryFile>
#include <QtCore/QTextStream>

#include <QtCore/QtAlgorithms>

#include <QtGui/QClipboard>
#include <QtGui/QDesktopServices>
#include <QtGui/QHeaderView>
#include <QtGui/QStyle>

#include <QtWebKit/QWebHistoryInterface>
#include <QtWebKit/QWebSettings>

#include <QtCore/QDebug>

static const unsigned int HISTORY_VERSION = 23;

HistoryManager::HistoryManager(QObject *parent)
    : QWebHistoryInterface(parent)
    , m_saveTimer(new AutoSaver(this))
    , m_historyLimit(30)
    , m_historyModel(0)
    , m_historyFilterModel(0)
    , m_historyTreeModel(0)
{
    m_expiredTimer.setSingleShot(true);
    connect(&m_expiredTimer, SIGNAL(timeout()),
            this, SLOT(checkForExpired()));
    connect(this, SIGNAL(entryAdded(HistoryItem)),
            m_saveTimer, SLOT(changeOccurred()));
    connect(this, SIGNAL(entryRemoved(HistoryItem)),
            m_saveTimer, SLOT(changeOccurred()));
    load();

    m_historyModel = new HistoryModel(this, this);
    m_historyFilterModel = new HistoryFilterModel(m_historyModel, this);
    m_historyTreeModel = new HistoryTreeModel(m_historyFilterModel, this);

    // QWebHistoryInterface will delete the history manager
    QWebHistoryInterface::setDefaultInterface(this);
}

HistoryManager::~HistoryManager()
{
    m_saveTimer->saveIfNeccessary();
}

QList<HistoryItem> HistoryManager::history() const
{
    return m_history;
}

bool HistoryManager::historyContains(const QString &url) const
{
    return m_historyFilterModel->historyContains(url);
}

void HistoryManager::addHistoryEntry(const QString &url)
{
    QUrl cleanUrl(url);
    cleanUrl.setPassword(QString());
    cleanUrl.setHost(cleanUrl.host().toLower());
    HistoryItem item(cleanUrl.toString(), QDateTime::currentDateTime());
    addHistoryItem(item);
}

void HistoryManager::setHistory(const QList<HistoryItem> &history, bool loadedAndSorted)
{
    m_history = history;

    // verify that it is sorted by date
    if (!loadedAndSorted)
        qSort(m_history.begin(), m_history.end());

    checkForExpired();

    if (loadedAndSorted) {
        m_lastSavedUrl = m_history.value(0).url;
    } else {
        m_lastSavedUrl = QString();
        m_saveTimer->changeOccurred();
    }
    emit historyReset();
}

HistoryModel *HistoryManager::historyModel() const
{
    return m_historyModel;
}

HistoryFilterModel *HistoryManager::historyFilterModel() const
{
    return m_historyFilterModel;
}

HistoryTreeModel *HistoryManager::historyTreeModel() const
{
    return m_historyTreeModel;
}

void HistoryManager::checkForExpired()
{
    if (m_historyLimit < 0 || m_history.isEmpty())
        return;

    QDateTime now = QDateTime::currentDateTime();
    int nextTimeout = 0;

    while (!m_history.isEmpty()) {
        QDateTime checkForExpired = m_history.last().dateTime;
        checkForExpired.setDate(checkForExpired.date().addDays(m_historyLimit));
        if (now.daysTo(checkForExpired) > 7) {
            // check at most in a week to prevent int overflows on the timer
            nextTimeout = 7 * 86400;
        } else {
            nextTimeout = now.secsTo(checkForExpired);
        }
        if (nextTimeout > 0)
            break;
        HistoryItem item = m_history.takeLast();
        // remove from saved file also
        m_lastSavedUrl = QString();
        emit entryRemoved(item);
    }

    if (nextTimeout > 0)
        m_expiredTimer.start(nextTimeout * 1000);
}

void HistoryManager::addHistoryItem(const HistoryItem &item)
{
    QWebSettings *globalSettings = QWebSettings::globalSettings();
    if (globalSettings->testAttribute(QWebSettings::PrivateBrowsingEnabled))
        return;

    m_history.prepend(item);
    emit entryAdded(item);
    if (m_history.count() == 1)
        checkForExpired();
}

void HistoryManager::updateHistoryItem(const QUrl &url, const QString &title)
{
    for (int i = 0; i < m_history.count(); ++i) {
        if (url == m_history.at(i).url) {
            m_history[i].title = title;
            m_saveTimer->changeOccurred();
            if (m_lastSavedUrl.isEmpty())
                m_lastSavedUrl = m_history.at(i).url;
            emit entryUpdated(i);
            break;
        }
    }
}

int HistoryManager::historyLimit() const
{
    return m_historyLimit;
}

void HistoryManager::setHistoryLimit(int limit)
{
    if (m_historyLimit == limit)
        return;
    m_historyLimit = limit;
    checkForExpired();
    m_saveTimer->changeOccurred();
}

void HistoryManager::clear()
{
    m_history.clear();
    m_lastSavedUrl = QString();
    m_saveTimer->changeOccurred();
    m_saveTimer->saveIfNeccessary();
    historyReset();
}

void HistoryManager::loadSettings()
{
    // load settings
    QSettings settings;
    settings.beginGroup(QLatin1String("history"));
    m_historyLimit = settings.value(QLatin1String("historyLimit"), 30).toInt();
}

void HistoryManager::load()
{
    loadSettings();

    QFile historyFile(QDesktopServices::storageLocation(QDesktopServices::DataLocation)
        + QLatin1String("/history"));
    if (!historyFile.exists())
        return;
    if (!historyFile.open(QFile::ReadOnly)) {
        qWarning() << "Unable to open history file" << historyFile.fileName();
        return;
    }

    QList<HistoryItem> list;
    QDataStream in(&historyFile);
    // Double check that the history file is sorted as it is read in
    bool needToSort = false;
    HistoryItem lastInsertedItem;
    QByteArray data;
    QDataStream stream;
    QBuffer buffer;
    stream.setDevice(&buffer);
    while (!historyFile.atEnd()) {
        in >> data;
        buffer.close();
        buffer.setBuffer(&data);
        buffer.open(QIODevice::ReadOnly);
        quint32 ver;
        stream >> ver;
        if (ver != HISTORY_VERSION)
            continue;
        HistoryItem item;
        stream >> item.url;
        stream >> item.dateTime;
        stream >> item.title;

        if (!item.dateTime.isValid())
            continue;

        if (item == lastInsertedItem) {
            if (lastInsertedItem.title.isEmpty() && !list.isEmpty())
                list[0].title = item.title;
            continue;
        }

        if (!needToSort && !list.isEmpty() && lastInsertedItem < item)
            needToSort = true;

        list.prepend(item);
        lastInsertedItem = item;
    }
    if (needToSort)
        qSort(list.begin(), list.end());

    setHistory(list, true);

    // If we had to sort re-write the whole history sorted
    if (needToSort) {
        m_lastSavedUrl = QString();
        m_saveTimer->changeOccurred();
    }
}

void HistoryManager::save()
{
    QSettings settings;
    settings.beginGroup(QLatin1String("history"));
    settings.setValue(QLatin1String("historyLimit"), m_historyLimit);

    bool saveAll = m_lastSavedUrl.isEmpty();
    int first = m_history.count() - 1;
    if (!saveAll) {
        // find the first one to save
        for (int i = 0; i < m_history.count(); ++i) {
            if (m_history.at(i).url == m_lastSavedUrl) {
                first = i - 1;
                break;
            }
        }
    }
    if (first == m_history.count() - 1)
        saveAll = true;

    QString directory = QDesktopServices::storageLocation(QDesktopServices::DataLocation);
    if (directory.isEmpty())
        directory = QDir::homePath() + QLatin1String("/.") + QCoreApplication::applicationName();
    if (!QFile::exists(directory)) {
        QDir dir;
        dir.mkpath(directory);
    }

    QFile historyFile(directory + QLatin1String("/history"));
    // When saving everything use a temporary file to prevent possible data loss.
    QTemporaryFile tempFile;
    tempFile.setAutoRemove(false);
    bool open = false;
    if (saveAll) {
        open = tempFile.open();
    } else {
        open = historyFile.open(QFile::Append);
    }

    if (!open) {
        qWarning() << "Unable to open history file for saving"
                   << (saveAll ? tempFile.fileName() : historyFile.fileName());
        return;
    }

    QDataStream out(saveAll ? &tempFile : &historyFile);
    for (int i = first; i >= 0; --i) {
        QByteArray data;
        QDataStream stream(&data, QIODevice::WriteOnly);
        HistoryItem item = m_history.at(i);
        stream << HISTORY_VERSION << item.url << item.dateTime << item.title;
        out << data;
    }
    tempFile.close();

    if (saveAll) {
        if (historyFile.exists() && !historyFile.remove())
            qWarning() << "History: error removing old history." << historyFile.errorString();
        if (!tempFile.rename(historyFile.fileName()))
            qWarning() << "History: error moving new history over old." << tempFile.errorString() << historyFile.fileName();
    }
    m_lastSavedUrl = m_history.value(0).url;
}

HistoryModel::HistoryModel(HistoryManager *history, QObject *parent)
    : QAbstractTableModel(parent)
    , m_history(history)
{
    Q_ASSERT(m_history);
    connect(m_history, SIGNAL(historyReset()),
            this, SLOT(historyReset()));
    connect(m_history, SIGNAL(entryRemoved(HistoryItem)),
            this, SLOT(historyReset()));

    connect(m_history, SIGNAL(entryAdded(HistoryItem)),
            this, SLOT(entryAdded()));
    connect(m_history, SIGNAL(entryUpdated(int)),
            this, SLOT(entryUpdated(int)));
}

void HistoryModel::historyReset()
{
    reset();
}

void HistoryModel::entryAdded()
{
    beginInsertRows(QModelIndex(), 0, 0);
    endInsertRows();
}

void HistoryModel::entryUpdated(int offset)
{
    QModelIndex idx = index(offset, 0);
    emit dataChanged(idx, idx);
}

QVariant HistoryModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    if (orientation == Qt::Horizontal
        && role == Qt::DisplayRole) {
        switch (section) {
            case 0: return tr("Title");
            case 1: return tr("Address");
        }
    }
    return QAbstractTableModel::headerData(section, orientation, role);
}

QVariant HistoryModel::data(const QModelIndex &index, int role) const
{
    QList<HistoryItem> lst = m_history->history();
    if (index.row() < 0 || index.row() >= lst.size())
        return QVariant();

    const HistoryItem &item = lst.at(index.row());
    switch (role) {
    case DateTimeRole:
        return item.dateTime;
    case DateRole:
        return item.dateTime.date();
    case UrlRole:
        return QUrl(item.url);
    case UrlStringRole:
        return item.url;
    case Qt::DisplayRole:
    case Qt::EditRole: {
        switch (index.column()) {
            case 0:
                // when there is no title try to generate one from the url
                if (item.title.isEmpty()) {
                    QString page = QFileInfo(QUrl(item.url).path()).fileName();
                    if (!page.isEmpty())
                        return page;
                    return item.url;
                }
                return item.title;
            case 1:
                return item.url;
        }
        }
    case Qt::DecorationRole:
        if (index.column() == 0) {
            return BrowserApplication::instance()->icon(item.url);
        }
    }
    return QVariant();
}

int HistoryModel::columnCount(const QModelIndex &parent) const
{
    return (parent.isValid()) ? 0 : 2;
}

int HistoryModel::rowCount(const QModelIndex &parent) const
{
    return (parent.isValid()) ? 0 : m_history->history().count();
}

bool HistoryModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (parent.isValid())
        return false;
    int lastRow = row + count - 1;
    beginRemoveRows(parent, row, lastRow);
    QList<HistoryItem> lst = m_history->history();
    for (int i = lastRow; i >= row; --i)
        lst.removeAt(i);
    disconnect(m_history, SIGNAL(historyReset()), this, SLOT(historyReset()));
    m_history->setHistory(lst);
    connect(m_history, SIGNAL(historyReset()), this, SLOT(historyReset()));
    endRemoveRows();
    return true;
}

#define MOVEDROWS 15

/*
    Maps the first bunch of items of the source model to the root
*/
HistoryMenuModel::HistoryMenuModel(HistoryTreeModel *sourceModel, QObject *parent)
    : QAbstractProxyModel(parent)
    , m_treeModel(sourceModel)
{
    setSourceModel(sourceModel);
}

int HistoryMenuModel::bumpedRows() const
{
    QModelIndex first = m_treeModel->index(0, 0);
    if (!first.isValid())
        return 0;
    return qMin(m_treeModel->rowCount(first), MOVEDROWS);
}

int HistoryMenuModel::columnCount(const QModelIndex &parent) const
{
    return m_treeModel->columnCount(mapToSource(parent));
}

int HistoryMenuModel::rowCount(const QModelIndex &parent) const
{
    if (parent.column() > 0)
        return 0;

    if (!parent.isValid()) {
        int folders = sourceModel()->rowCount();
        int bumpedItems = bumpedRows();
        if (bumpedItems <= MOVEDROWS
            && bumpedItems == sourceModel()->rowCount(sourceModel()->index(0, 0)))
            --folders;
        return bumpedItems + folders;
    }

    if (parent.internalId() == -1) {
        if (parent.row() < bumpedRows())
            return 0;
    }

    QModelIndex idx = mapToSource(parent);
    int defaultCount = sourceModel()->rowCount(idx);
    if (idx == sourceModel()->index(0, 0))
        return defaultCount - bumpedRows();
    return defaultCount;
}

QModelIndex HistoryMenuModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    // currently not used or autotested
    Q_ASSERT(false);
    int sr = m_treeModel->mapToSource(sourceIndex).row();
    return createIndex(sourceIndex.row(), sourceIndex.column(), sr);
}

QModelIndex HistoryMenuModel::mapToSource(const QModelIndex &proxyIndex) const
{
    if (!proxyIndex.isValid())
        return QModelIndex();

    if (proxyIndex.internalId() == -1) {
        int bumpedItems = bumpedRows();
        if (proxyIndex.row() < bumpedItems)
            return m_treeModel->index(proxyIndex.row(), proxyIndex.column(), m_treeModel->index(0, 0));
        if (bumpedItems <= MOVEDROWS && bumpedItems == sourceModel()->rowCount(m_treeModel->index(0, 0)))
            --bumpedItems;
        return m_treeModel->index(proxyIndex.row() - bumpedItems, proxyIndex.column());
    }

    QModelIndex historyIndex = m_treeModel->sourceModel()->index(proxyIndex.internalId(), proxyIndex.column());
    QModelIndex treeIndex = m_treeModel->mapFromSource(historyIndex);
    return treeIndex;
}

QModelIndex HistoryMenuModel::index(int row, int column, const QModelIndex &parent) const
{
    if (row < 0
        || column < 0 || column >= columnCount(parent)
        || parent.column() > 0)
        return QModelIndex();
    if (!parent.isValid())
        return createIndex(row, column, -1);

    QModelIndex treeIndexParent = mapToSource(parent);

    int bumpedItems = 0;
    if (treeIndexParent == m_treeModel->index(0, 0))
        bumpedItems = bumpedRows();
    QModelIndex treeIndex = m_treeModel->index(row + bumpedItems, column, treeIndexParent);
    QModelIndex historyIndex = m_treeModel->mapToSource(treeIndex);
    int historyRow = historyIndex.row();
    if (historyRow == -1)
        historyRow = treeIndex.row();
    return createIndex(row, column, historyRow);
}

QModelIndex HistoryMenuModel::parent(const QModelIndex &index) const
{
    int offset = index.internalId();
    if (offset == -1 || !index.isValid())
        return QModelIndex();

    QModelIndex historyIndex = m_treeModel->sourceModel()->index(index.internalId(), 0);
    QModelIndex treeIndex = m_treeModel->mapFromSource(historyIndex);
    QModelIndex treeIndexParent = treeIndex.parent();

    int sr = m_treeModel->mapToSource(treeIndexParent).row();
    int bumpedItems = bumpedRows();
    if (bumpedItems <= MOVEDROWS && bumpedItems == sourceModel()->rowCount(sourceModel()->index(0, 0)))
        --bumpedItems;
    return createIndex(bumpedItems + treeIndexParent.row(), treeIndexParent.column(), sr);
}


HistoryMenu::HistoryMenu(QWidget *parent)
    : ModelMenu(parent)
    , m_history(0)
{
    connect(this, SIGNAL(activated(QModelIndex)),
            this, SLOT(activated(QModelIndex)));
    setHoverRole(HistoryModel::UrlStringRole);
}

void HistoryMenu::activated(const QModelIndex &index)
{
    emit openUrl(index.data(HistoryModel::UrlRole).toUrl());
}

bool HistoryMenu::prePopulated()
{
    if (!m_history) {
        m_history = BrowserApplication::historyManager();
        m_historyMenuModel = new HistoryMenuModel(m_history->historyTreeModel(), this);
        setModel(m_historyMenuModel);
    }
    // initial actions
    for (int i = 0; i < m_initialActions.count(); ++i)
        addAction(m_initialActions.at(i));
    if (!m_initialActions.isEmpty())
        addSeparator();
    setFirstSeparator(m_historyMenuModel->bumpedRows());

    return false;
}

void HistoryMenu::postPopulated()
{
    if (m_history->history().count() > 0)
        addSeparator();

    QAction *showAllAction = new QAction(tr("Show All History"), this);
    connect(showAllAction, SIGNAL(triggered()), this, SLOT(showHistoryDialog()));
    addAction(showAllAction);

    QAction *clearAction = new QAction(tr("Clear History"), this);
    connect(clearAction, SIGNAL(triggered()), m_history, SLOT(clear()));
    addAction(clearAction);
}

void HistoryMenu::showHistoryDialog()
{
    HistoryDialog *dialog = new HistoryDialog(this);
    connect(dialog, SIGNAL(openUrl(QUrl)),
            this, SIGNAL(openUrl(QUrl)));
    dialog->show();
}

void HistoryMenu::setInitialActions(QList<QAction*> actions)
{
    m_initialActions = actions;
    for (int i = 0; i < m_initialActions.count(); ++i)
        addAction(m_initialActions.at(i));
}

TreeProxyModel::TreeProxyModel(QObject *parent) : QSortFilterProxyModel(parent)
{
    setSortRole(HistoryModel::DateTimeRole);
    setFilterCaseSensitivity(Qt::CaseInsensitive);
}

bool TreeProxyModel::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
    if (!source_parent.isValid())
        return true;
    return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
}

HistoryDialog::HistoryDialog(QWidget *parent, HistoryManager *setHistory) : QDialog(parent)
{
    HistoryManager *history = setHistory;
    if (!history)
        history = BrowserApplication::historyManager();
    setupUi(this);
    tree->setUniformRowHeights(true);
    tree->setSelectionBehavior(QAbstractItemView::SelectRows);
    tree->setTextElideMode(Qt::ElideMiddle);
    QAbstractItemModel *model = history->historyTreeModel();
    TreeProxyModel *proxyModel = new TreeProxyModel(this);
    connect(search, SIGNAL(textChanged(QString)),
            proxyModel, SLOT(setFilterFixedString(QString)));
    connect(removeButton, SIGNAL(clicked()), tree, SLOT(removeOne()));
    connect(removeAllButton, SIGNAL(clicked()), history, SLOT(clear()));
    proxyModel->setSourceModel(model);
    tree->setModel(proxyModel);
    tree->setExpanded(proxyModel->index(0, 0), true);
    tree->setAlternatingRowColors(true);
    QFontMetrics fm(font());
    int header = fm.width(QLatin1Char('m')) * 40;
    tree->header()->resizeSection(0, header);
    tree->header()->setStretchLastSection(true);
    connect(tree, SIGNAL(activated(QModelIndex)),
            this, SLOT(open()));
    tree->setContextMenuPolicy(Qt::CustomContextMenu);
    connect(tree, SIGNAL(customContextMenuRequested(QPoint)),
            this, SLOT(customContextMenuRequested(QPoint)));
}

void HistoryDialog::customContextMenuRequested(const QPoint &pos)
{
    QMenu menu;
    QModelIndex index = tree->indexAt(pos);
    index = index.sibling(index.row(), 0);
    if (index.isValid() && !tree->model()->hasChildren(index)) {
        menu.addAction(tr("Open"), this, SLOT(open()));
        menu.addSeparator();
        menu.addAction(tr("Copy"), this, SLOT(copy()));
    }
    menu.addAction(tr("Delete"), tree, SLOT(removeOne()));
    menu.exec(QCursor::pos());
}

void HistoryDialog::open()
{
    QModelIndex index = tree->currentIndex();
    if (!index.parent().isValid())
        return;
    emit openUrl(index.data(HistoryModel::UrlRole).toUrl());
}

void HistoryDialog::copy()
{
    QModelIndex index = tree->currentIndex();
    if (!index.parent().isValid())
        return;
    QString url = index.data(HistoryModel::UrlStringRole).toString();

    QClipboard *clipboard = QApplication::clipboard();
    clipboard->setText(url);
}

HistoryFilterModel::HistoryFilterModel(QAbstractItemModel *sourceModel, QObject *parent)
    : QAbstractProxyModel(parent),
    m_loaded(false)
{
    setSourceModel(sourceModel);
}

int HistoryFilterModel::historyLocation(const QString &url) const
{
    load();
    if (!m_historyHash.contains(url))
        return 0;
    return sourceModel()->rowCount() - m_historyHash.value(url);
}

QVariant HistoryFilterModel::data(const QModelIndex &index, int role) const
{
    return QAbstractProxyModel::data(index, role);
}

void HistoryFilterModel::setSourceModel(QAbstractItemModel *newSourceModel)
{
    if (sourceModel()) {
        disconnect(sourceModel(), SIGNAL(modelReset()), this, SLOT(sourceReset()));
        disconnect(sourceModel(), SIGNAL(dataChanged(QModelIndex,QModelIndex)),
                   this, SLOT(dataChanged(QModelIndex,QModelIndex)));
        disconnect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceRowsInserted(QModelIndex,int,int)));
        disconnect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    }

    QAbstractProxyModel::setSourceModel(newSourceModel);

    if (sourceModel()) {
        m_loaded = false;
        connect(sourceModel(), SIGNAL(modelReset()), this, SLOT(sourceReset()));
        connect(sourceModel(), SIGNAL(dataChanged(QModelIndex,QModelIndex)),
                   this, SLOT(sourceDataChanged(QModelIndex,QModelIndex)));
        connect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceRowsInserted(QModelIndex,int,int)));
        connect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    }
}

void HistoryFilterModel::sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
    emit dataChanged(mapFromSource(topLeft), mapFromSource(bottomRight));
}

QVariant HistoryFilterModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    return sourceModel()->headerData(section, orientation, role);
}

void HistoryFilterModel::sourceReset()
{
    m_loaded = false;
    reset();
}

int HistoryFilterModel::rowCount(const QModelIndex &parent) const
{
    load();
    if (parent.isValid())
        return 0;
    return m_historyHash.count();
}

int HistoryFilterModel::columnCount(const QModelIndex &parent) const
{
    return (parent.isValid()) ? 0 : 2;
}

QModelIndex HistoryFilterModel::mapToSource(const QModelIndex &proxyIndex) const
{
    load();
    int sourceRow = sourceModel()->rowCount() - proxyIndex.internalId();
    return sourceModel()->index(sourceRow, proxyIndex.column());
}

QModelIndex HistoryFilterModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    load();
    QString url = sourceIndex.data(HistoryModel::UrlStringRole).toString();
    if (!m_historyHash.contains(url))
        return QModelIndex();

    // This can be done in a binary search, but we can't use qBinary find
    // because it can't take: qBinaryFind(m_sourceRow.end(), m_sourceRow.begin(), v);
    // so if this is a performance bottlneck then convert to binary search, until then
    // the cleaner/easier to read code wins the day.
    int realRow = -1;
    int sourceModelRow = sourceModel()->rowCount() - sourceIndex.row();

    for (int i = 0; i < m_sourceRow.count(); ++i) {
        if (m_sourceRow.at(i) == sourceModelRow) {
            realRow = i;
            break;
        }
    }
    if (realRow == -1)
        return QModelIndex();

    return createIndex(realRow, sourceIndex.column(), sourceModel()->rowCount() - sourceIndex.row());
}

QModelIndex HistoryFilterModel::index(int row, int column, const QModelIndex &parent) const
{
    load();
    if (row < 0 || row >= rowCount(parent)
        || column < 0 || column >= columnCount(parent))
        return QModelIndex();

    return createIndex(row, column, m_sourceRow[row]);
}

QModelIndex HistoryFilterModel::parent(const QModelIndex &) const
{
    return QModelIndex();
}

void HistoryFilterModel::load() const
{
    if (m_loaded)
        return;
    m_sourceRow.clear();
    m_historyHash.clear();
    m_historyHash.reserve(sourceModel()->rowCount());
    for (int i = 0; i < sourceModel()->rowCount(); ++i) {
        QModelIndex idx = sourceModel()->index(i, 0);
        QString url = idx.data(HistoryModel::UrlStringRole).toString();
        if (!m_historyHash.contains(url)) {
            m_sourceRow.append(sourceModel()->rowCount() - i);
            m_historyHash[url] = sourceModel()->rowCount() - i;
        }
    }
    m_loaded = true;
}

void HistoryFilterModel::sourceRowsInserted(const QModelIndex &parent, int start, int end)
{
    Q_ASSERT(start == end && start == 0);
    Q_UNUSED(end);
    if (!m_loaded)
        return;
    QModelIndex idx = sourceModel()->index(start, 0, parent);
    QString url = idx.data(HistoryModel::UrlStringRole).toString();
    if (m_historyHash.contains(url)) {
        int sourceRow = sourceModel()->rowCount() - m_historyHash[url];
        int realRow = mapFromSource(sourceModel()->index(sourceRow, 0)).row();
        beginRemoveRows(QModelIndex(), realRow, realRow);
        m_sourceRow.removeAt(realRow);
        m_historyHash.remove(url);
        endRemoveRows();
    }
    beginInsertRows(QModelIndex(), 0, 0);
    m_historyHash.insert(url, sourceModel()->rowCount() - start);
    m_sourceRow.insert(0, sourceModel()->rowCount());
    endInsertRows();
}

void HistoryFilterModel::sourceRowsRemoved(const QModelIndex &, int start, int end)
{
    Q_UNUSED(start);
    Q_UNUSED(end);
    sourceReset();
}

/*
    Removing a continuous block of rows will remove filtered rows too as this is
    the users intention.
*/
bool HistoryFilterModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (row < 0 || count <= 0 || row + count > rowCount(parent) || parent.isValid())
        return false;
    int lastRow = row + count - 1;
    disconnect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    beginRemoveRows(parent, row, lastRow);
    int oldCount = rowCount();
    int start = sourceModel()->rowCount() - m_sourceRow.value(row);
    int end = sourceModel()->rowCount() - m_sourceRow.value(lastRow);
    sourceModel()->removeRows(start, end - start + 1);
    endRemoveRows();
    connect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    m_loaded = false;
    if (oldCount - count != rowCount())
        reset();
    return true;
}

HistoryCompletionModel::HistoryCompletionModel(QObject *parent)
    : QAbstractProxyModel(parent)
{
}

QVariant HistoryCompletionModel::data(const QModelIndex &index, int role) const
{
    if (sourceModel()
        && (role == Qt::EditRole || role == Qt::DisplayRole)
        && index.isValid()) {
        QModelIndex idx = mapToSource(index);
        idx = idx.sibling(idx.row(), 1);
        QString urlString = idx.data(HistoryModel::UrlStringRole).toString();
        if (index.row() % 2) {
            QUrl url = urlString;
            QString s = url.toString(QUrl::RemoveScheme
                                     | QUrl::RemoveUserInfo
                                     | QUrl::StripTrailingSlash);
            return s.mid(2);  // strip // from the front
        }
        return urlString;
    }
    return QAbstractProxyModel::data(index, role);
}

int HistoryCompletionModel::rowCount(const QModelIndex &parent) const
{
    return (parent.isValid() || !sourceModel()) ? 0 : sourceModel()->rowCount(parent) * 2;
}

int HistoryCompletionModel::columnCount(const QModelIndex &parent) const
{
    return (parent.isValid()) ? 0 : 1;
}

QModelIndex HistoryCompletionModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    int row = sourceIndex.row() * 2;
    return index(row, sourceIndex.column());
}

QModelIndex HistoryCompletionModel::mapToSource(const QModelIndex &proxyIndex) const
{
    if (!sourceModel())
        return QModelIndex();
    int row = proxyIndex.row() / 2;
    return sourceModel()->index(row, proxyIndex.column());
}

QModelIndex HistoryCompletionModel::index(int row, int column, const QModelIndex &parent) const
{
    if (row < 0 || row >= rowCount(parent)
        || column < 0 || column >= columnCount(parent))
        return QModelIndex();
    return createIndex(row, column, 0);
}

QModelIndex HistoryCompletionModel::parent(const QModelIndex &) const
{
    return QModelIndex();
}

void HistoryCompletionModel::setSourceModel(QAbstractItemModel *newSourceModel)
{
    if (sourceModel()) {
        disconnect(sourceModel(), SIGNAL(modelReset()), this, SLOT(sourceReset()));
        disconnect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceReset()));
        disconnect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceReset()));
    }

    QAbstractProxyModel::setSourceModel(newSourceModel);

    if (newSourceModel) {
        connect(newSourceModel, SIGNAL(modelReset()), this, SLOT(sourceReset()));
        connect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceReset()));
        connect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceReset()));
    }

    reset();
}

void HistoryCompletionModel::sourceReset()
{
    reset();
}

HistoryTreeModel::HistoryTreeModel(QAbstractItemModel *sourceModel, QObject *parent)
    : QAbstractProxyModel(parent)
{
    setSourceModel(sourceModel);
}

QVariant HistoryTreeModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    return sourceModel()->headerData(section, orientation, role);
}

QVariant HistoryTreeModel::data(const QModelIndex &index, int role) const
{
    if ((role == Qt::EditRole || role == Qt::DisplayRole)) {
        int start = index.internalId();
        if (start == 0) {
            int offset = sourceDateRow(index.row());
            if (index.column() == 0) {
                QModelIndex idx = sourceModel()->index(offset, 0);
                QDate date = idx.data(HistoryModel::DateRole).toDate();
                if (date == QDate::currentDate())
                    return tr("Earlier Today");
                return date.toString(QLatin1String("dddd, MMMM d, yyyy"));
            }
            if (index.column() == 1) {
                return tr("%1 items").arg(rowCount(index.sibling(index.row(), 0)));
            }
        }
    }
    if (role == Qt::DecorationRole && index.column() == 0 && !index.parent().isValid())
        return QIcon(QLatin1String(":history.png"));
    if (role == HistoryModel::DateRole && index.column() == 0 && index.internalId() == 0) {
        int offset = sourceDateRow(index.row());
        QModelIndex idx = sourceModel()->index(offset, 0);
        return idx.data(HistoryModel::DateRole);
    }

    return QAbstractProxyModel::data(index, role);
}

int HistoryTreeModel::columnCount(const QModelIndex &parent) const
{
    return sourceModel()->columnCount(mapToSource(parent));
}

int HistoryTreeModel::rowCount(const QModelIndex &parent) const
{
    if ( parent.internalId() != 0
        || parent.column() > 0
        || !sourceModel())
        return 0;

    // row count OF dates
    if (!parent.isValid()) {
        if (!m_sourceRowCache.isEmpty())
            return m_sourceRowCache.count();
        QDate currentDate;
        int rows = 0;
        int totalRows = sourceModel()->rowCount();

        for (int i = 0; i < totalRows; ++i) {
            QDate rowDate = sourceModel()->index(i, 0).data(HistoryModel::DateRole).toDate();
            if (rowDate != currentDate) {
                m_sourceRowCache.append(i);
                currentDate = rowDate;
                ++rows;
            }
        }
        Q_ASSERT(m_sourceRowCache.count() == rows);
        return rows;
    }

    // row count FOR a date
    int start = sourceDateRow(parent.row());
    int end = sourceDateRow(parent.row() + 1);
    return (end - start);
}

// Translate the top level date row into the offset where that date starts
int HistoryTreeModel::sourceDateRow(int row) const
{
    if (row <= 0)
        return 0;

    if (m_sourceRowCache.isEmpty())
        rowCount(QModelIndex());

    if (row >= m_sourceRowCache.count()) {
        if (!sourceModel())
            return 0;
        return sourceModel()->rowCount();
    }
    return m_sourceRowCache.at(row);
}

QModelIndex HistoryTreeModel::mapToSource(const QModelIndex &proxyIndex) const
{
    int offset = proxyIndex.internalId();
    if (offset == 0)
        return QModelIndex();
    int startDateRow = sourceDateRow(offset - 1);
    return sourceModel()->index(startDateRow + proxyIndex.row(), proxyIndex.column());
}

QModelIndex HistoryTreeModel::index(int row, int column, const QModelIndex &parent) const
{
    if (row < 0
        || column < 0 || column >= columnCount(parent)
        || parent.column() > 0)
        return QModelIndex();

    if (!parent.isValid())
        return createIndex(row, column, 0);
    return createIndex(row, column, parent.row() + 1);
}

QModelIndex HistoryTreeModel::parent(const QModelIndex &index) const
{
    int offset = index.internalId();
    if (offset == 0 || !index.isValid())
        return QModelIndex();
    return createIndex(offset - 1, 0, 0);
}

bool HistoryTreeModel::hasChildren(const QModelIndex &parent) const
{
    QModelIndex grandparent = parent.parent();
    if (!grandparent.isValid())
        return true;
    return false;
}

Qt::ItemFlags HistoryTreeModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;
    return Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled;
}

bool HistoryTreeModel::removeRows(int row, int count, const QModelIndex &parent)
{
    if (row < 0 || count <= 0 || row + count > rowCount(parent))
        return false;

    if (parent.isValid()) {
        // removing pages
        int offset = sourceDateRow(parent.row());
        return sourceModel()->removeRows(offset + row, count);
    } else {
        // removing whole dates
        for (int i = row + count - 1; i >= row; --i) {
            QModelIndex dateParent = index(i, 0);
            int offset = sourceDateRow(dateParent.row());
            if (!sourceModel()->removeRows(offset, rowCount(dateParent)))
                return false;
        }
    }
    return true;
}

void HistoryTreeModel::setSourceModel(QAbstractItemModel *newSourceModel)
{
    if (sourceModel()) {
        disconnect(sourceModel(), SIGNAL(modelReset()), this, SLOT(sourceReset()));
        disconnect(sourceModel(), SIGNAL(layoutChanged()), this, SLOT(sourceReset()));
        disconnect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceRowsInserted(QModelIndex,int,int)));
        disconnect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    }

    QAbstractProxyModel::setSourceModel(newSourceModel);

    if (newSourceModel) {
        connect(sourceModel(), SIGNAL(modelReset()), this, SLOT(sourceReset()));
        connect(sourceModel(), SIGNAL(layoutChanged()), this, SLOT(sourceReset()));
        connect(sourceModel(), SIGNAL(rowsInserted(QModelIndex,int,int)),
                this, SLOT(sourceRowsInserted(QModelIndex,int,int)));
        connect(sourceModel(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(sourceRowsRemoved(QModelIndex,int,int)));
    }

    reset();
}

void HistoryTreeModel::sourceReset()
{
    m_sourceRowCache.clear();
    reset();
}

void HistoryTreeModel::sourceRowsInserted(const QModelIndex &parent, int start, int end)
{
    Q_UNUSED(parent); // Avoid warnings when compiling release
    Q_ASSERT(!parent.isValid());
    if (start != 0 || start != end) {
        m_sourceRowCache.clear();
        reset();
        return;
    }

    m_sourceRowCache.clear();
    QModelIndex treeIndex = mapFromSource(sourceModel()->index(start, 0));
    QModelIndex treeParent = treeIndex.parent();
    if (rowCount(treeParent) == 1) {
        beginInsertRows(QModelIndex(), 0, 0);
        endInsertRows();
    } else {
        beginInsertRows(treeParent, treeIndex.row(), treeIndex.row());
        endInsertRows();
    }
}

QModelIndex HistoryTreeModel::mapFromSource(const QModelIndex &sourceIndex) const
{
    if (!sourceIndex.isValid())
        return QModelIndex();

    if (m_sourceRowCache.isEmpty())
        rowCount(QModelIndex());

    QList<int>::iterator it;
    it = qLowerBound(m_sourceRowCache.begin(), m_sourceRowCache.end(), sourceIndex.row());
    if (*it != sourceIndex.row())
        --it;
    int dateRow = qMax(0, it - m_sourceRowCache.begin());
    int row = sourceIndex.row() - m_sourceRowCache.at(dateRow);
    return createIndex(row, sourceIndex.column(), dateRow + 1);
}

void HistoryTreeModel::sourceRowsRemoved(const QModelIndex &parent, int start, int end)
{
    Q_UNUSED(parent); // Avoid warnings when compiling release
    Q_ASSERT(!parent.isValid());
    if (m_sourceRowCache.isEmpty())
        return;
    for (int i = end; i >= start;) {
        QList<int>::iterator it;
        it = qLowerBound(m_sourceRowCache.begin(), m_sourceRowCache.end(), i);
        // playing it safe
        if (it == m_sourceRowCache.end()) {
            m_sourceRowCache.clear();
            reset();
            return;
        }

        if (*it != i)
            --it;
        int row = qMax(0, it - m_sourceRowCache.begin());
        int offset = m_sourceRowCache[row];
        QModelIndex dateParent = index(row, 0);
        // If we can remove all the rows in the date do that and skip over them
        int rc = rowCount(dateParent);
        if (i - rc + 1 == offset && start <= i - rc + 1) {
            beginRemoveRows(QModelIndex(), row, row);
            m_sourceRowCache.removeAt(row);
            i -= rc + 1;
        } else {
            beginRemoveRows(dateParent, i - offset, i - offset);
            ++row;
            --i;
        }
        for (int j = row; j < m_sourceRowCache.count(); ++j)
            --m_sourceRowCache[j];
        endRemoveRows();
    }
}