/*
 * Bittorrent Client using Qt4 and libtorrent.
 * Copyright (C) 2006  Christophe Dumez
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link this program with the OpenSSL project's "OpenSSL" library (or with
 * modified versions of it that use the same license as the "OpenSSL" library),
 * and distribute the linked executables. You must obey the GNU General Public
 * License in all respects for all of the code used other than "OpenSSL".  If you
 * modify file(s), you may extend this exception to your version of the file(s),
 * but you are not obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * Contact : chris@qbittorrent.org
 */

#include <QStandardItemModel>
#include <QHeaderView>
#include <QMessageBox>
#include <QTemporaryFile>
#include <QSystemTrayIcon>
#include <iostream>
#include <QTimer>
#include <QDir>
#include <QMenu>
#include <QClipboard>
#include <QMimeData>
#include <QSortFilterProxyModel>
#include <QFileDialog>
#include <QDesktopServices>
#include <QClipboard>

#ifdef Q_OS_WIN
#include <stdlib.h>
#endif

#include "searchengine.h"
#include "core/bittorrent/session.h"
#include "core/utils/fs.h"
#include "core/utils/misc.h"
#include "core/preferences.h"
#include "searchlistdelegate.h"
#include "mainwindow.h"
#include "addnewtorrentdialog.h"
#include "guiiconprovider.h"
#include "lineedit.h"

#define SEARCHHISTORY_MAXSIZE 50

/*SEARCH ENGINE START*/
SearchEngine::SearchEngine(MainWindow* parent)
    : QWidget(parent)
    , search_pattern(new LineEdit(this))
    , mp_mainWindow(parent)
{
    setupUi(this);
    searchBarLayout->insertWidget(0, search_pattern);
    connect(search_pattern, SIGNAL(returnPressed()), search_button, SLOT(click()));
    // Icons
    search_button->setIcon(GuiIconProvider::instance()->getIcon("edit-find"));
    download_button->setIcon(GuiIconProvider::instance()->getIcon("download"));
    goToDescBtn->setIcon(GuiIconProvider::instance()->getIcon("application-x-mswinurl"));
    enginesButton->setIcon(GuiIconProvider::instance()->getIcon("preferences-system-network"));
    copyURLBtn->setIcon(GuiIconProvider::instance()->getIcon("edit-copy"));
    tabWidget->setTabsClosable(true);
    connect(tabWidget, SIGNAL(tabCloseRequested(int)), this, SLOT(closeTab(int)));
    // Boolean initialization
    search_stopped = false;
    // Creating Search Process
    searchProcess = new QProcess(this);
    searchProcess->setEnvironment(QProcess::systemEnvironment());
    connect(searchProcess, SIGNAL(started()), this, SLOT(searchStarted()));
    connect(searchProcess, SIGNAL(readyReadStandardOutput()), this, SLOT(readSearchOutput()));
    connect(searchProcess, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(searchFinished(int,QProcess::ExitStatus)));
    connect(tabWidget, SIGNAL(currentChanged(int)), this, SLOT(tab_changed(int)));
    searchTimeout = new QTimer(this);
    searchTimeout->setSingleShot(true);
    connect(searchTimeout, SIGNAL(timeout()), this, SLOT(on_search_button_clicked()));
    // Update nova.py search plugin if necessary
    updateNova();
    supported_engines = new SupportedEngines();
    // Fill in category combobox
    fillCatCombobox();
    fillEngineComboBox();

    connect(search_pattern, SIGNAL(textEdited(QString)), this, SLOT(searchTextEdited(QString)));
    connect(selectEngine, SIGNAL(currentIndexChanged(const QString &)), this, SLOT(selectMultipleBox(const QString &)));
}

void SearchEngine::fillCatCombobox()
{
    comboCategory->clear();
    comboCategory->addItem(full_cat_names["all"], QVariant("all"));
    QStringList supported_cat = supported_engines->supportedCategories();
    foreach (QString cat, supported_cat) {
        qDebug("Supported category: %s", qPrintable(cat));
        comboCategory->addItem(full_cat_names[cat], QVariant(cat));
    }
}

void SearchEngine::fillEngineComboBox()
{
    selectEngine->clear();
    selectEngine->addItem(tr("All enabled"), QVariant("enabled"));
    selectEngine->addItem(tr("All engines"), QVariant("all"));
    foreach (QString engi, supported_engines->enginesEnabled())
        selectEngine->addItem(engi, QVariant(engi));
    selectEngine->addItem(tr("Multiple..."), QVariant("multi"));
}

QString SearchEngine::selectedCategory() const
{
    return comboCategory->itemData(comboCategory->currentIndex()).toString();
}

QString SearchEngine::selectedEngine() const
{
    return selectEngine->itemData(selectEngine->currentIndex()).toString();
}

SearchEngine::~SearchEngine()
{
    qDebug("Search destruction");
    searchProcess->kill();
    searchProcess->waitForFinished();
    foreach (QProcess *downloader, downloaders) {
        // Make sure we disconnect the SIGNAL/SLOT first
        // To avoid qreal free
        downloader->disconnect();
        downloader->kill();
        downloader->waitForFinished();
        delete downloader;
    }
    delete search_pattern;
    delete searchTimeout;
    delete searchProcess;
    delete supported_engines;
}

void SearchEngine::tab_changed(int t)
{
    //when we switch from a tab that is not empty to another that is empty the download button
    //doesn't have to be available
    if (t > -1) {
        //-1 = no more tab
        currentSearchTab = all_tab.at(tabWidget->currentIndex());
        if (currentSearchTab->getCurrentSearchListModel()->rowCount()) {
            download_button->setEnabled(true);
            goToDescBtn->setEnabled(true);
            copyURLBtn->setEnabled(true);
        }
        else {
            download_button->setEnabled(false);
            goToDescBtn->setEnabled(false);
            copyURLBtn->setEnabled(false);
        }
        search_status->setText(currentSearchTab->status);
    }
}

void SearchEngine::selectMultipleBox(const QString &text)
{
    if (text == tr("Multiple...")) on_enginesButton_clicked();
}

void SearchEngine::on_enginesButton_clicked()
{
    engineSelectDlg *dlg = new engineSelectDlg(this, supported_engines);
    connect(dlg, SIGNAL(enginesChanged()), this, SLOT(fillCatCombobox()));
    connect(dlg, SIGNAL(enginesChanged()), this, SLOT(fillEngineComboBox()));
}

void SearchEngine::searchTextEdited(QString)
{
    // Enable search button
    search_button->setText(tr("Search"));
    newQueryString = true;
}

void SearchEngine::giveFocusToSearchInput()
{
    search_pattern->setFocus();
}

// Function called when we click on search button
void SearchEngine::on_search_button_clicked()
{
    if (Utils::Misc::pythonVersion() < 0) {
        mp_mainWindow->showNotificationBaloon(tr("Search Engine"), tr("Please install Python to use the Search Engine."));
        return;
    }

    if (searchProcess->state() != QProcess::NotRunning) {
#ifdef Q_OS_WIN
        searchProcess->kill();
#else
        searchProcess->terminate();
#endif
        search_stopped = true;
        if (searchTimeout->isActive())
            searchTimeout->stop();

        searchProcess->waitForFinished(1000);

        if (!newQueryString) {
            search_button->setText(tr("Search"));
            return;
        }
    }

    newQueryString = false;

    // Reload environment variables (proxy)
    searchProcess->setEnvironment(QProcess::systemEnvironment());

    const QString pattern = search_pattern->text().trimmed();
    // No search pattern entered
    if (pattern.isEmpty()) {
        QMessageBox::critical(0, tr("Empty search pattern"), tr("Please type a search pattern first"));
        return;
    }
    // Tab Addition
    currentSearchTab = new SearchTab(this);
    activeSearchTab = currentSearchTab;
    connect(currentSearchTab->header(), SIGNAL(sectionResized(int, int, int)), this, SLOT(saveResultsColumnsWidth()));
    all_tab.append(currentSearchTab);
    QString tabName = pattern;
    tabName.replace(QRegExp("&{1}"), "&&");
    tabWidget->addTab(currentSearchTab, tabName);
    tabWidget->setCurrentWidget(currentSearchTab);

    // Getting checked search engines
    QStringList params;
    search_stopped = false;
    params << Utils::Fs::toNativePath(Utils::Fs::searchEngineLocation() + "/nova2.py");
    if (selectedEngine() == "all") params << supported_engines->enginesAll().join(",");
    else if (selectedEngine() == "enabled") params << supported_engines->enginesEnabled().join(",");
    else if (selectedEngine() == "multi") params << supported_engines->enginesEnabled().join(",");
    else params << selectedEngine();
    qDebug("Search with category: %s", qPrintable(selectedCategory()));
    params << selectedCategory();
    params << pattern.split(" ");
    // Update SearchEngine widgets
    no_search_results = true;
    nb_search_results = 0;
    search_result_line_truncated.clear();
    // Changing the text of the current label
    activeSearchTab->getCurrentLabel()->setText(tr("Results <i>(%1)</i>:", "i.e: Search results").arg(0));
    // Launch search
    searchProcess->start(Utils::Misc::pythonExecutable(), params, QIODevice::ReadOnly);
    searchTimeout->start(180000); // 3min
}

void SearchEngine::saveResultsColumnsWidth()
{
    if (all_tab.isEmpty())
        return;
    QTreeView* treeview = all_tab.first()->getCurrentTreeView();
    Preferences* const pref = Preferences::instance();
    QStringList new_width_list;
    short nbColumns = all_tab.first()->getCurrentSearchListModel()->columnCount();
    for (short i = 0; i < nbColumns; ++i)
        if (treeview->columnWidth(i) > 0)
            new_width_list << QString::number(treeview->columnWidth(i));
    // Don't save the width of the last column (auto column width)
    new_width_list.removeLast();
    pref->setSearchColsWidth(new_width_list.join(" "));
}

void SearchEngine::downloadTorrent(QString engine_url, QString torrent_url)
{
    if (torrent_url.startsWith("bc://bt/", Qt::CaseInsensitive)) {
        qDebug("Converting bc link to magnet link");
        torrent_url = Utils::Misc::bcLinkToMagnet(torrent_url);
    }
    qDebug() << Q_FUNC_INFO << torrent_url;
    if (torrent_url.startsWith("magnet:")) {
        QStringList urls;
        urls << torrent_url;
        mp_mainWindow->downloadFromURLList(urls);
    }
    else {
        QProcess *downloadProcess = new QProcess(this);
        downloadProcess->setEnvironment(QProcess::systemEnvironment());
        connect(downloadProcess, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(downloadFinished(int,QProcess::ExitStatus)));
        downloaders << downloadProcess;
        QStringList params;
        params << Utils::Fs::toNativePath(Utils::Fs::searchEngineLocation() + "/nova2dl.py");
        params << engine_url;
        params << torrent_url;
        // Launch search
        downloadProcess->start(Utils::Misc::pythonExecutable(), params, QIODevice::ReadOnly);
    }
}

void SearchEngine::searchStarted()
{
    // Update SearchEngine widgets
    activeSearchTab->status = tr("Searching...");
    search_status->setText(currentSearchTab->status);
    search_status->repaint();
    search_button->setText(tr("Stop"));
}

// search Qprocess return output as soon as it gets new
// stuff to read. We split it into lines and add each
// line to search results calling appendSearchResult().
void SearchEngine::readSearchOutput()
{
    QByteArray output = searchProcess->readAllStandardOutput();
    output.replace("\r", "");
    QList<QByteArray> lines_list = output.split('\n');
    if (!search_result_line_truncated.isEmpty()) {
        QByteArray end_of_line = lines_list.takeFirst();
        lines_list.prepend(search_result_line_truncated + end_of_line);
    }
    search_result_line_truncated = lines_list.takeLast().trimmed();
    foreach (const QByteArray &line, lines_list)
        appendSearchResult(QString::fromUtf8(line));
    activeSearchTab->getCurrentLabel()->setText(tr("Results <i>(%1)</i>:", "i.e: Search results").arg(nb_search_results));
}

void SearchEngine::downloadFinished(int exitcode, QProcess::ExitStatus)
{
    QProcess *downloadProcess = (QProcess*)sender();
    if (exitcode == 0) {
        QString line = QString::fromUtf8(downloadProcess->readAllStandardOutput()).trimmed();
        QStringList parts = line.split(' ');
        if (parts.size() == 2) {
            QString path = parts[0];

            if (Preferences::instance()->useAdditionDialog())
                AddNewTorrentDialog::show(path, mp_mainWindow);
            else
                BitTorrent::Session::instance()->addTorrent(path);
        }
    }
    qDebug("Deleting downloadProcess");
    downloaders.removeOne(downloadProcess);
    delete downloadProcess;
}

static inline void removePythonScriptIfExists(const QString& script_path)
{
    Utils::Fs::forceRemove(script_path);
    Utils::Fs::forceRemove(script_path + "c");
}

// Update nova.py search plugin if necessary
void SearchEngine::updateNova()
{
    qDebug("Updating nova");
    // create nova directory if necessary
    QDir search_dir(Utils::Fs::searchEngineLocation());
    QString nova_folder = Utils::Misc::pythonVersion() >= 3 ? "nova3" : "nova";
    QFile package_file(search_dir.absoluteFilePath("__init__.py"));
    package_file.open(QIODevice::WriteOnly | QIODevice::Text);
    package_file.close();
    if (!search_dir.exists("engines"))
        search_dir.mkdir("engines");
    Utils::Fs::removeDirRecursive(search_dir.absoluteFilePath("__pycache__"));

    QFile package_file2(search_dir.absolutePath() + "/engines/__init__.py");
    package_file2.open(QIODevice::WriteOnly | QIODevice::Text);
    package_file2.close();
    // Copy search plugin files (if necessary)
    QString filePath = search_dir.absoluteFilePath("nova2.py");
    if (getPluginVersion(":/" + nova_folder + "/nova2.py") > getPluginVersion(filePath)) {
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/nova2.py", filePath);
    }

    filePath = search_dir.absoluteFilePath("nova2dl.py");
    if (getPluginVersion(":/" + nova_folder + "/nova2dl.py") > getPluginVersion(filePath)) {
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/nova2dl.py", filePath);
    }

    filePath = search_dir.absoluteFilePath("novaprinter.py");
    if (getPluginVersion(":/" + nova_folder + "/novaprinter.py") > getPluginVersion(filePath)) {
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/novaprinter.py", filePath);
    }

    filePath = search_dir.absoluteFilePath("helpers.py");
    if (getPluginVersion(":/" + nova_folder + "/helpers.py") > getPluginVersion(filePath)) {
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/helpers.py", filePath);
    }

    filePath = search_dir.absoluteFilePath("socks.py");
    removePythonScriptIfExists(filePath);
    QFile::copy(":/" + nova_folder + "/socks.py", filePath);

    if (nova_folder == "nova") {
        filePath = search_dir.absoluteFilePath("fix_encoding.py");
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/fix_encoding.py", filePath);
    }
    else if (nova_folder == "nova3") {
        filePath = search_dir.absoluteFilePath("sgmllib3.py");
        removePythonScriptIfExists(filePath);
        QFile::copy(":/" + nova_folder + "/sgmllib3.py", filePath);
    }
    QDir destDir(QDir(Utils::Fs::searchEngineLocation()).absoluteFilePath("engines"));
    Utils::Fs::removeDirRecursive(destDir.absoluteFilePath("__pycache__"));
    QDir shipped_subDir(":/" + nova_folder + "/engines/");
    QStringList files = shipped_subDir.entryList();
    foreach (const QString &file, files) {
        QString shipped_file = shipped_subDir.absoluteFilePath(file);
        // Copy python classes
        if (file.endsWith(".py")) {
            const QString dest_file = destDir.absoluteFilePath(file);
            if (getPluginVersion(shipped_file) > getPluginVersion(dest_file) ) {
                qDebug("shipped %s is more recent then local plugin, updating...", qPrintable(file));
                removePythonScriptIfExists(dest_file);
                qDebug("%s copied to %s", qPrintable(shipped_file), qPrintable(dest_file));
                QFile::copy(shipped_file, dest_file);
            }
        }
        else {
            // Copy icons
            if (file.endsWith(".png"))
                if (!QFile::exists(destDir.absoluteFilePath(file)))
                    QFile::copy(shipped_file, destDir.absoluteFilePath(file));
        }
    }
}

// Slot called when search is Finished
// Search can be finished for 3 reasons :
// Error | Stopped by user | Finished normally
void SearchEngine::searchFinished(int exitcode, QProcess::ExitStatus)
{
    if (searchTimeout->isActive())
        searchTimeout->stop();
    bool useNotificationBalloons = Preferences::instance()->useProgramNotification();
    if (useNotificationBalloons && mp_mainWindow->getCurrentTabWidget() != this)
        mp_mainWindow->showNotificationBaloon(tr("Search Engine"), tr("Search has finished"));

    if (activeSearchTab.isNull())
        // The active tab was closed
        return;

    if (exitcode) {
#ifdef Q_OS_WIN
        activeSearchTab->status = tr("Search aborted");
#else
        activeSearchTab->status = tr("An error occurred during search...");
#endif
    }
    else {
        if (search_stopped) {
            activeSearchTab->status = tr("Search aborted");
        }
        else {
            if (no_search_results)
                activeSearchTab->status = tr("Search returned no results");
            else
                activeSearchTab->status = tr("Search has finished");
        }
    }
    search_status->setText(currentSearchTab->status);
    activeSearchTab = 0;
    search_button->setText(tr("Search"));
}

// SLOT to append one line to search results list
// Line is in the following form :
// file url | file name | file size | nb seeds | nb leechers | Search engine url
void SearchEngine::appendSearchResult(const QString &line)
{
    if (activeSearchTab.isNull()) {
        if (searchProcess->state() != QProcess::NotRunning) {
#ifdef Q_OS_WIN
            searchProcess->kill();
#else
            searchProcess->terminate();
#endif
            searchProcess->waitForFinished(1000);
        }
        if (searchTimeout->isActive())
            searchTimeout->stop();
        search_stopped = true;
        return;
    }
    const QStringList parts = line.split("|");
    const int nb_fields = parts.size();
    if (nb_fields < NB_PLUGIN_COLUMNS - 1) //-1 because desc_link is optional
        return;
    Q_ASSERT(activeSearchTab);
    // Add item to search result list
    QStandardItemModel* cur_model = activeSearchTab->getCurrentSearchListModel();
    Q_ASSERT(cur_model);
    int row = cur_model->rowCount();
    cur_model->insertRow(row);

    cur_model->setData(cur_model->index(row, SearchSortModel::DL_LINK), parts.at(PL_DL_LINK).trimmed()); // download URL
    cur_model->setData(cur_model->index(row, SearchSortModel::NAME), parts.at(PL_NAME).trimmed()); // Name
    cur_model->setData(cur_model->index(row, SearchSortModel::SIZE), parts.at(PL_SIZE).trimmed().toLongLong()); // Size
    bool ok = false;
    qlonglong nb_seeders = parts.at(PL_SEEDS).trimmed().toLongLong(&ok);
    if (!ok || nb_seeders < 0)
        cur_model->setData(cur_model->index(row, SearchSortModel::SEEDS), -1); // Seeders
    else
        cur_model->setData(cur_model->index(row, SearchSortModel::SEEDS), nb_seeders); // Seeders
    qlonglong nb_leechers = parts.at(PL_LEECHS).trimmed().toLongLong(&ok);
    if (!ok || nb_leechers < 0)
        cur_model->setData(cur_model->index(row, SearchSortModel::LEECHS), -1); // Leechers
    else
        cur_model->setData(cur_model->index(row, SearchSortModel::LEECHS), nb_leechers); // Leechers
    cur_model->setData(cur_model->index(row, SearchSortModel::ENGINE_URL), parts.at(PL_ENGINE_URL).trimmed()); // Engine URL
    // Description Link
    if (nb_fields == NB_PLUGIN_COLUMNS)
        cur_model->setData(cur_model->index(row, SearchSortModel::DESC_LINK), parts.at(PL_DESC_LINK).trimmed());

    no_search_results = false;
    ++nb_search_results;
    // Enable clear & download buttons
    download_button->setEnabled(true);
    goToDescBtn->setEnabled(true);
    copyURLBtn->setEnabled(true);
}

void SearchEngine::closeTab(int index)
{
    // Search is run for active tab so if user decided to close it, then stop search
    if (!activeSearchTab.isNull() && index == tabWidget->indexOf(activeSearchTab)) {
        qDebug("Closed active search Tab");
        if (searchProcess->state() != QProcess::NotRunning) {
#ifdef Q_OS_WIN
            searchProcess->kill();
#else
            searchProcess->terminate();
#endif
            searchProcess->waitForFinished(1000);
        }
        if (searchTimeout->isActive())
            searchTimeout->stop();
        search_stopped = true;
        activeSearchTab = 0;
    }
    delete all_tab.takeAt(index);
    if (!all_tab.size()) {
        download_button->setEnabled(false);
        goToDescBtn->setEnabled(false);
        search_status->setText(tr("Stopped"));
        copyURLBtn->setEnabled(false);
    }
}

// Download selected items in search results list
void SearchEngine::on_download_button_clicked()
{
    //QModelIndexList selectedIndexes = currentSearchTab->getCurrentTreeView()->selectionModel()->selectedIndexes();
    QModelIndexList selectedIndexes = all_tab.at(tabWidget->currentIndex())->getCurrentTreeView()->selectionModel()->selectedIndexes();
    foreach (const QModelIndex &index, selectedIndexes) {
        if (index.column() == SearchSortModel::NAME) {
            // Get Item url
            QSortFilterProxyModel* model = all_tab.at(tabWidget->currentIndex())->getCurrentSearchListProxy();
            QString torrent_url = model->data(model->index(index.row(), URL_COLUMN)).toString();
            QString engine_url = model->data(model->index(index.row(), ENGINE_URL_COLUMN)).toString();
            downloadTorrent(engine_url, torrent_url);
            all_tab.at(tabWidget->currentIndex())->setRowColor(index.row(), "blue");
        }
    }
}

void SearchEngine::on_goToDescBtn_clicked()
{
    QModelIndexList selectedIndexes = all_tab.at(tabWidget->currentIndex())->getCurrentTreeView()->selectionModel()->selectedIndexes();
    foreach (const QModelIndex &index, selectedIndexes) {
        if (index.column() == SearchSortModel::NAME) {
            QSortFilterProxyModel* model = all_tab.at(tabWidget->currentIndex())->getCurrentSearchListProxy();
            const QString desc_url = model->data(model->index(index.row(), SearchSortModel::DESC_LINK)).toString();
            if (!desc_url.isEmpty())
                QDesktopServices::openUrl(QUrl::fromEncoded(desc_url.toUtf8()));
        }
    }
}

void SearchEngine::on_copyURLBtn_clicked()
{
    QStringList urls;
    QModelIndexList selectedIndexes = all_tab.at(tabWidget->currentIndex())->getCurrentTreeView()->selectionModel()->selectedIndexes();
    foreach (const QModelIndex &index, selectedIndexes) {
        if (index.column() == SearchSortModel::NAME) {
            QSortFilterProxyModel* model = all_tab.at(tabWidget->currentIndex())->getCurrentSearchListProxy();
            const QString descUrl = model->data(model->index(index.row(), SearchSortModel::DESC_LINK)).toString();
            if (!descUrl.isEmpty())
                urls << descUrl.toUtf8();
        }
    }
    if (!urls.empty()) {
        QClipboard *clipboard = QApplication::clipboard();
        clipboard->setText(urls.join("\n"));
    }
}