#include "UserSettings.h"
#include "AppConfig.h"

#include <QCoreApplication>
#include <QDir>
#include <QFileInfo>
#include <QRect>
#include <QSettings>
#include <QtGlobal>

namespace
{
    const char kXor[] = "IM-Client-local";

    QString encodeSecret(const QString &plain)
    {
        if (plain.isEmpty())
            return QString();
        QByteArray raw = plain.toUtf8();
        const int kn = static_cast<int>(sizeof(kXor) - 1);
        for (int i = 0; i < raw.size(); ++i)
            raw[i] = raw[i] ^ kXor[i % kn];
        return QString::fromLatin1(raw.toBase64());
    }

    QString decodeSecret(const QString &stored)
    {
        if (stored.isEmpty())
            return QString();
        QByteArray raw = QByteArray::fromBase64(stored.toLatin1());
        const int kn = static_cast<int>(sizeof(kXor) - 1);
        for (int i = 0; i < raw.size(); ++i)
            raw[i] = raw[i] ^ kXor[i % kn];
        return QString::fromUtf8(raw);
    }

    void applyIniCodec(QSettings &ini)
    {
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
        ini.setIniCodec("UTF-8");
#else
        Q_UNUSED(ini);
#endif
    }
}

UserSettings &UserSettings::instance()
{
    static UserSettings s;
    return s;
}

bool UserSettings::load()
{
    QString dir;
    if (AppConfig::instance().loaded())
        dir = QFileInfo(AppConfig::instance().path()).absolutePath();
    else
        dir = QDir::cleanPath(QCoreApplication::applicationDirPath() + QStringLiteral("/config"));

    QDir().mkpath(dir);
    m_path = dir + QStringLiteral("/user.ini");

    QSettings ini(m_path, QSettings::IniFormat);
    applyIniCodec(ini);

    m_account = ini.value(QStringLiteral("login/account")).toString().trimmed();
    m_nickname = ini.value(QStringLiteral("login/nickname")).toString().trimmed();
    m_rememberPassword = ini.value(QStringLiteral("login/remember_password"), false).toBool();
    m_autoLogin = ini.value(QStringLiteral("login/auto_login"), false).toBool();
    if (m_rememberPassword)
        m_password = decodeSecret(ini.value(QStringLiteral("login/password")).toString());
    else
        m_password.clear();
    if (!m_rememberPassword)
        m_autoLogin = false;

    m_fontPreset = ini.value(QStringLiteral("ui/font_preset")).toString().trimmed();
    if (m_fontPreset.isEmpty())
    {
        QSettings legacyNim(QStringLiteral("NIM"), QStringLiteral("Client"));
        m_fontPreset = legacyNim.value(QStringLiteral("ui/fontPreset")).toString();
        if (m_fontPreset.isEmpty())
        {
            QSettings legacyIm(QStringLiteral("IM"), QStringLiteral("Client"));
            m_fontPreset = legacyIm.value(QStringLiteral("ui/fontPreset"), QStringLiteral("system")).toString();
        }
        if (m_fontPreset.isEmpty())
            m_fontPreset = QStringLiteral("system");
        persist();
    }

    const int x = ini.value(QStringLiteral("window/x"), -1).toInt();
    const int y = ini.value(QStringLiteral("window/y"), -1).toInt();
    const int w = ini.value(QStringLiteral("window/w"), 0).toInt();
    const int h = ini.value(QStringLiteral("window/h"), 0).toInt();
    if (w > 0 && h > 0)
        m_windowRect = QRect(x, y, w, h);
    m_windowMaximized = ini.value(QStringLiteral("window/maximized"), false).toBool();
    const QString closeAct = ini.value(QStringLiteral("window/close_action")).toString().trimmed();
    if (closeAct == QLatin1String("tray"))
        m_closeAction = 1;
    else if (closeAct == QLatin1String("quit"))
        m_closeAction = 2;
    else
        m_closeAction = 0;
    return true;
}

void UserSettings::persist() const
{
    if (m_path.isEmpty())
        return;

    QSettings ini(m_path, QSettings::IniFormat);
    applyIniCodec(ini);
    ini.setValue(QStringLiteral("login/account"), m_account);
    ini.setValue(QStringLiteral("login/nickname"), m_nickname);
    ini.setValue(QStringLiteral("login/remember_password"), m_rememberPassword);
    ini.setValue(QStringLiteral("login/auto_login"), m_autoLogin && m_rememberPassword);
    ini.setValue(QStringLiteral("login/password"),
                 m_rememberPassword ? encodeSecret(m_password) : QString());
    ini.setValue(QStringLiteral("ui/font_preset"), m_fontPreset);
    if (m_windowRect.isValid())
    {
        ini.setValue(QStringLiteral("window/x"), m_windowRect.x());
        ini.setValue(QStringLiteral("window/y"), m_windowRect.y());
        ini.setValue(QStringLiteral("window/w"), m_windowRect.width());
        ini.setValue(QStringLiteral("window/h"), m_windowRect.height());
    }
    ini.setValue(QStringLiteral("window/maximized"), m_windowMaximized);
    if (m_closeAction == 1)
        ini.setValue(QStringLiteral("window/close_action"), QStringLiteral("tray"));
    else if (m_closeAction == 2)
        ini.setValue(QStringLiteral("window/close_action"), QStringLiteral("quit"));
    else
        ini.remove(QStringLiteral("window/close_action"));
    ini.sync();
}

void UserSettings::saveLogin(const QString &account, const QString &nickname,
                             const QString &password, bool rememberPassword, bool autoLogin)
{
    m_account = account.trimmed();
    m_nickname = nickname.trimmed();
    m_rememberPassword = rememberPassword && !password.isEmpty();
    m_autoLogin = autoLogin && m_rememberPassword;
    m_password = m_rememberPassword ? password : QString();
    persist();
}

void UserSettings::setFontPreset(const QString &key)
{
    m_fontPreset = key.isEmpty() ? QStringLiteral("system") : key;
    persist();
}

void UserSettings::saveWindow(const QRect &rect, bool maximized)
{
    if (rect.width() > 0 && rect.height() > 0)
        m_windowRect = rect;
    m_windowMaximized = maximized;
    persist();
}

void UserSettings::setCloseAction(int action)
{
    m_closeAction = (action == 1 || action == 2) ? action : 0;
    persist();
}