/* ============================================================
* QupZilla - WebKit based browser
* Copyright (C) 2010-2012  David Rosca <nowrep@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>.
* ============================================================ */
#include "searchenginesmanager.h"
#include "searchenginesdialog.h"
#include "editsearchengine.h"
#include "iconprovider.h"
#include "mainapplication.h"
#include "networkmanager.h"
#include "opensearchreader.h"
#include "opensearchengine.h"
#include "databasewriter.h"
#include "settings.h"
#include "webview.h"

#include <QNetworkReply>
#include <QMessageBox>
#include <QWebElement>

#define ENSURE_LOADED if (!m_settingsLoaded) loadSettings();

QIcon SearchEnginesManager::iconForSearchEngine(const QUrl &url)
{
    QIcon ic = qIconProvider->iconFromImage(qIconProvider->iconForDomain(url));
    if (ic.isNull()) {
        ic = QIcon(":icons/menu/search-icon.png");
    }

    return ic;
}

SearchEnginesManager::SearchEnginesManager()
    : QObject()
    , m_settingsLoaded(false)
    , m_saveScheduled(false)
{
    Settings settings;
    settings.beginGroup("SearchEngines");
    m_startingEngineName = settings.value("activeEngine", "Google").toString();
    settings.endGroup();

    connect(this, SIGNAL(enginesChanged()), this, SLOT(scheduleSave()));
}

void SearchEnginesManager::loadSettings()
{
    m_settingsLoaded = true;

    QSqlQuery query;
    query.exec("SELECT name, icon, url, shortcut, suggestionsUrl FROM search_engines");
    while (query.next()) {
        Engine en;
        en.name = query.value(0).toString();
        en.icon = qIconProvider->iconFromBase64(query.value(1).toByteArray());
        en.url = query.value(2).toString();
        en.shortcut = query.value(3).toString();
        en.suggestionsUrl = query.value(4).toString();

        m_allEngines.append(en);
    }

    if (m_allEngines.isEmpty()) {
        restoreDefaults();
    }
}

SearchEngine SearchEnginesManager::engineForShortcut(const QString &shortcut)
{
    Engine returnEngine;
    if (shortcut.isEmpty()) {
        return returnEngine;
    }

    foreach(const Engine & en, m_allEngines) {
        if (en.shortcut == shortcut) {
            returnEngine = en;
            break;
        }
    }

    return returnEngine;
}

QUrl SearchEnginesManager::searchUrl(const Engine &engine, const QString &string)
{
    ENSURE_LOADED;

    QByteArray url = engine.url.toUtf8();
    url.replace("%s", QUrl::toPercentEncoding(string));
    return QUrl::fromEncoded(url);
}

QUrl SearchEnginesManager::searchUrl(const QString &string)
{
    return searchUrl(m_activeEngine, string);
}

void SearchEnginesManager::restoreDefaults()
{
    Engine google;
    google.name = "Google";
    google.icon = QIcon(":icons/sites/google.png");
    google.url = "http://www.google.com/search?client=qupzilla&q=%s";
    google.shortcut = "g";
    google.suggestionsUrl = "http://suggestqueries.google.com/complete/search?output=firefox&q=%s";

    Engine wiki;
    wiki.name = "Wikipedia (en)";
    wiki.icon = QIcon(":/icons/sites/wikipedia.png");
    wiki.url = "http://en.wikipedia.org/wiki/Special:Search?search=%s&fulltext=Search";
    wiki.shortcut = "w";
    wiki.suggestionsUrl = "http://en.wikipedia.org/w/api.php?action=opensearch&search=%s&namespace=0";

    Engine yt;
    yt.name = "YouTube";
    yt.icon = QIcon(":/icons/sites/youtube.png");
    yt.url = "http://www.youtube.com/results?search_query=%s&search=Search";
    yt.shortcut = "yt";
    yt.suggestionsUrl = "http://suggestqueries.google.com/complete/search?ds=yt&output=firefox&q=%s";

    Engine duck;
    duck.name = "DuckDuckGo";
    duck.icon = QIcon(":/icons/sites/duck.png");
    duck.url = "https://duckduckgo.com/?q=%s&t=qupzilla";
    duck.shortcut = "d";

    addEngine(google);
    addEngine(wiki);
    addEngine(yt);
    addEngine(duck);

    emit enginesChanged();
}

void SearchEnginesManager::engineChangedImage()
{
    OpenSearchEngine* engine = qobject_cast<OpenSearchEngine*>(sender());

    if (!engine) {
        return;
    }

    foreach(Engine e, m_allEngines) {
        if (e.name == engine->name() && e.url.contains(engine->searchUrl("%s").toString())
                && !engine->image().isNull()) {

            int index = m_allEngines.indexOf(e);
            if (index != -1) {
                m_allEngines[index].icon = QIcon(QPixmap::fromImage(engine->image()));

                emit enginesChanged();

                delete engine;
                break;
            }
        }
    }
}

void SearchEnginesManager::editEngine(const Engine &before, const Engine &after)
{
    removeEngine(before);
    addEngine(after);
}

void SearchEnginesManager::addEngine(const Engine &engine)
{
    ENSURE_LOADED;

    if (m_allEngines.contains(engine)) {
        return;
    }

    m_allEngines.append(engine);

    emit enginesChanged();
}

void SearchEnginesManager::addEngineFromForm(const QWebElement &element, WebView* view)
{
    QWebElement formElement = element.parent();

    while (!formElement.isNull()) {
        if (formElement.tagName().toLower() == "form") {
            break;
        }

        formElement = formElement.parent();
    }

    if (formElement.isNull()) {
        return;
    }

    QUrl actionUrl = QUrl::fromEncoded(formElement.attribute("action").toUtf8());

    if (actionUrl.isRelative()) {
        actionUrl = view->url().resolved(actionUrl);
    }

    actionUrl.addQueryItem(element.attribute("name"), "%s");

    QList<QPair<QByteArray, QByteArray> > queryItems;
    QWebElementCollection allInputs = formElement.findAll("input");
    foreach(QWebElement e, allInputs) {
        if (element == e || !e.hasAttribute("name")) {
            continue;
        }

        QPair<QByteArray, QByteArray> item;
        item.first = QUrl::toPercentEncoding(e.attribute("name").toUtf8());
        item.second = QUrl::toPercentEncoding(e.evaluateJavaScript("this.value").toByteArray());

        queryItems.append(item);
    }

    actionUrl.setEncodedQueryItems(queryItems + actionUrl.encodedQueryItems());

    SearchEngine engine;
    engine.name = view->title();
    engine.icon = view->icon();
    engine.url = actionUrl.toString();

    EditSearchEngine dialog(SearchEnginesDialog::tr("Add Search Engine"), view);
    dialog.setName(engine.name);
    dialog.setIcon(engine.icon);
    dialog.setUrl(engine.url);

    if (dialog.exec() != QDialog::Accepted) {
        return;
    }

    engine.name = dialog.name();
    engine.icon = dialog.icon();
    engine.url = dialog.url();
    engine.shortcut = dialog.shortcut();

    if (engine.name.isEmpty() || engine.url.isEmpty()) {
        return;
    }

    addEngine(engine);
}

void SearchEnginesManager::addEngine(OpenSearchEngine* engine)
{
    ENSURE_LOADED;

    Engine en;
    en.name = engine->name();
    en.url = engine->searchUrl("searchstring").toString().replace("searchstring", "%s");
    if (engine->image().isNull()) {
        en.icon = iconForSearchEngine(engine->searchUrl(QString()));
    }
    else {
        en.icon = QIcon(QPixmap::fromImage(engine->image()));
    }
    en.suggestionsUrl = engine->getSuggestionsUrl();
    en.suggestionsParameters = engine->getSuggestionsParameters();

    addEngine(en);

    connect(engine, SIGNAL(imageChanged()), this, SLOT(engineChangedImage()));
}

void SearchEnginesManager::addEngine(const QUrl &url)
{
    ENSURE_LOADED;

    if (!url.isValid()) {
        return;
    }

    qApp->setOverrideCursor(Qt::WaitCursor);

    QNetworkReply* reply = mApp->networkManager()->get(QNetworkRequest(url));
    reply->setParent(this);
    connect(reply, SIGNAL(finished()), this, SLOT(replyFinished()));
}

void SearchEnginesManager::replyFinished()
{
    qApp->restoreOverrideCursor();

    QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
    if (!reply) {
        return;
    }

    if (reply->error() != QNetworkReply::NoError) {
        reply->close();
        reply->deleteLater();
        return;
    }

    OpenSearchReader reader;
    OpenSearchEngine* engine = reader.read(reply);
    engine->setNetworkAccessManager(mApp->networkManager());

    reply->close();
    reply->deleteLater();

    if (checkEngine(engine)) {
        addEngine(engine);
        QMessageBox::information(0, tr("Search Engine Added"), tr("Search Engine \"%1\" has been successfully added.").arg(engine->name()));
    }
}

bool SearchEnginesManager::checkEngine(OpenSearchEngine* engine)
{
    if (!engine->isValid()) {
        QString errorString = tr("Search Engine is not valid!");
        QMessageBox::warning(0, tr("Error"), tr("Error while adding Search Engine <br><b>Error Message: </b> %1").arg(errorString));

        return false;
    }

    return true;
}

void SearchEnginesManager::setActiveEngine(const Engine &engine)
{
    ENSURE_LOADED;

    if (!m_allEngines.contains(engine)) {
        return;
    }

    m_activeEngine = engine;
    emit activeEngineChanged();
}

void SearchEnginesManager::removeEngine(const Engine &engine)
{
    ENSURE_LOADED;

    if (!m_allEngines.contains(engine)) {
        return;
    }

    QSqlQuery query;
    query.prepare("DELETE FROM search_engines WHERE name=? AND url=?");
    query.bindValue(0, engine.name);
    query.bindValue(1, engine.url);
    query.exec();

    m_allEngines.removeOne(engine);
    emit enginesChanged();
}

void SearchEnginesManager::setAllEngines(const QList<Engine> &engines)
{
    ENSURE_LOADED;

    m_allEngines = engines;
    emit enginesChanged();
}

QList<SearchEngine> SearchEnginesManager::allEngines()
{
    ENSURE_LOADED;

    return m_allEngines;
}

void SearchEnginesManager::saveSettings()
{
    Settings settings;
    settings.beginGroup("SearchEngines");
    settings.setValue("activeEngine", m_activeEngine.name);
    settings.endGroup();

    if (!m_saveScheduled) {
        return;
    }

    // Well, this is not the best implementation to do as this is taking some time.
    // Actually, it is delaying the quit of app for about a 1 sec on my machine with only
    // 5 engines. Another problem is that deleting rows without VACUUM isn't actually freeing
    // space in database.
    //
    // But as long as user is not playing with search engines every run it is acceptable.

    QSqlQuery query;
    query.exec("DELETE FROM search_engines");

    foreach(const Engine & en, m_allEngines) {
        query.prepare("INSERT INTO search_engines (name, icon, url, shortcut, suggestionsUrl, suggestionsParameters) VALUES (?, ?, ?, ?, ?, ?)");
        query.bindValue(0, en.name);
        query.bindValue(1, qIconProvider->iconToBase64(en.icon));
        query.bindValue(2, en.url);
        query.bindValue(3, en.shortcut);
        query.bindValue(4, en.suggestionsUrl);
        query.bindValue(5, en.suggestionsParameters);

        query.exec();
    }
}