#include "./qtconfigarguments.h"

#include <c++utilities/conversion/stringconversion.h>

#include <QFont>
#include <QIcon>
#include <QLocale>
#include <QString>
#ifdef QT_UTILITIES_GUI_QTWIDGETS
#include <QApplication>
#include <QStyleFactory>
#else
#include <QGuiApplication>
#endif

#include <initializer_list>
#include <iostream>

using namespace std;
using namespace ConversionUtilities;

namespace ApplicationUtilities {

/*!
 * \brief Constructs new Qt config arguments.
 */
QtConfigArguments::QtConfigArguments()
    : m_qtWidgetsGuiArg("qt-widgets-gui", 'g', "shows a Qt widgets based graphical user interface")
    , m_qtQuickGuiArg("qt-quick-gui", 'q', "shows a Qt quick based graphical user interface")
    , m_lngArg("lang", 'l', "sets the language for the Qt GUI")
    , m_qmlDebuggerArg("qmljsdebugger", '\0', "enables QML debugging (see "
                                              "http://doc.qt.io/qt-5/"
                                              "qtquick-debugging.html)")
    , m_styleArg("style", '\0', "sets the Qt widgets style")
    , m_iconThemeArg("icon-theme", '\0', "sets the icon theme and additional "
                                         "theme search paths for the Qt GUI")
    , m_fontArg("font", '\0', "sets the font family and size (point) for the Qt GUI")
    , m_libraryPathsArg("library-paths", '\0', "sets the list of directories to search when loading "
                                               "libraries (all existing paths will be deleted)")
    , m_platformThemeArg("platformtheme", '\0', "specifies the Qt platform theme to be used")
{
    // language
    m_lngArg.setValueNames({ "language" });
    m_lngArg.setRequiredValueCount(1);
    m_lngArg.setRequired(false);
    m_lngArg.setCombinable(true);
    // qml debugger (handled by Qt, just to let the parser know of it)
    m_qmlDebuggerArg.setValueNames({ "port:<port_from>[,port_to][,host:<ip address>][,block]" });
    m_qmlDebuggerArg.setRequiredValueCount(1);
    m_qmlDebuggerArg.setCombinable(true);
    // appearance
    m_styleArg.setValueNames({ "style name" });
    m_styleArg.setRequiredValueCount(1);
    m_styleArg.setCombinable(true);
    m_iconThemeArg.setValueNames({ "theme name", "search path 1", "search path 2" });
    m_iconThemeArg.setRequiredValueCount(-1);
    m_iconThemeArg.setCombinable(true);
    m_fontArg.setValueNames({ "name", "size" });
    m_fontArg.setRequiredValueCount(2);
    m_fontArg.setCombinable(true);
    m_libraryPathsArg.setValueNames({ "path 1", "path 2" });
    m_libraryPathsArg.setRequiredValueCount(-1);
    m_libraryPathsArg.setCombinable(true);
    m_platformThemeArg.setRequiredValueCount(1);
    m_platformThemeArg.setCombinable(true);
    m_platformThemeArg.setValueNames({ "qt5ct/kde/..." });
    m_platformThemeArg.setPreDefinedCompletionValues("qt5ct kde gnome");
    m_qtWidgetsGuiArg.setSubArguments(
        { &m_lngArg, &m_qmlDebuggerArg, &m_styleArg, &m_iconThemeArg, &m_fontArg, &m_libraryPathsArg, &m_platformThemeArg });
    m_qtQuickGuiArg.setSubArguments({ &m_lngArg, &m_qmlDebuggerArg, &m_iconThemeArg, &m_fontArg, &m_libraryPathsArg, &m_platformThemeArg });
    m_qtWidgetsGuiArg.setDenotesOperation(true);
    m_qtQuickGuiArg.setDenotesOperation(true);
#if defined QT_UTILITIES_GUI_QTWIDGETS
    m_qtWidgetsGuiArg.setImplicit(true);
#elif defined QT_UTILITIES_GUI_QTQUICK
    m_qtQuickGuiArg.setImplicit(true);
#endif
}

/*!
 * \brief Applies the settings from the arguments.
 * \remarks Also checks environment variables for the icon theme.
 * \param preventApplyingDefaultFont If true, the font will not be updated to
 * some default value if no font has been specified explicitly.
 */
void QtConfigArguments::applySettings(bool preventApplyingDefaultFont) const
{
    if (m_lngArg.isPresent()) {
        QLocale::setDefault(QLocale(QString::fromLocal8Bit(m_lngArg.values().front())));
    }
    if (m_styleArg.isPresent()) {
#ifdef QT_UTILITIES_GUI_QTWIDGETS
        if (QStyle *style = QStyleFactory::create(QString::fromLocal8Bit(m_styleArg.values().front()))) {
            QApplication::setStyle(style);
        } else {
            cerr << "Warning: Can not find the specified style." << endl;
        }
#else
#ifdef QT_UTILITIES_GUI_QTQUICK
        cerr << "Warning: Can not set a style for the Qt Quick GUI." << endl;
#endif
#endif
    }
    if (m_iconThemeArg.isPresent()) {
        auto i = m_iconThemeArg.values().cbegin(), end = m_iconThemeArg.values().end();
        if (i != end) {
            QIcon::setThemeName(QString::fromLocal8Bit(*i));
            if (++i != end) {
                QStringList searchPaths;
                searchPaths.reserve(m_iconThemeArg.values().size() - 1);
                for (; i != end; ++i) {
                    searchPaths << QString::fromLocal8Bit(*i);
                }
                searchPaths << QStringLiteral(":/icons");
                QIcon::setThemeSearchPaths(searchPaths);
            }
        }
    } else {
        if (qEnvironmentVariableIsSet("ICON_THEME_SEARCH_PATH")) {
            QString path;
            path.append(qgetenv("ICON_THEME_SEARCH_PATH"));
            QIcon::setThemeSearchPaths(QStringList() << path << QStringLiteral(":/icons"));
        } else {
            QIcon::setThemeSearchPaths(QIcon::themeSearchPaths() << QStringLiteral("../share/icons") << QStringLiteral(":/icons"));
        }
        if (qEnvironmentVariableIsSet("ICON_THEME")) {
            QString themeName;
            themeName.append(qgetenv("ICON_THEME"));
            QIcon::setThemeName(themeName);
        }
    }
#ifdef Q_OS_WIN32
    // default configuration under Windows
    if (QIcon::themeName().isEmpty()) {
        QIcon::setThemeName(QStringLiteral("default"));
    }
#endif
    if (m_fontArg.isPresent()) {
        QFont font;
        font.setFamily(QString::fromLocal8Bit(m_fontArg.values().front()));
        try {
            font.setPointSize(stringToNumber<int>(m_fontArg.values().back()));
        } catch (const ConversionException &) {
            cerr << "Warning: The specified font size is no number and will be "
                    "ignored."
                 << endl;
        }
        QGuiApplication::setFont(font);
    }
#ifdef Q_OS_WIN32
    else if (!preventApplyingDefaultFont) {
        QGuiApplication::setFont(QFont(QStringLiteral("Segoe UI"), 9));
    }
#else
    VAR_UNUSED(preventApplyingDefaultFont)
#endif
    if (m_libraryPathsArg.isPresent()) {
        QStringList libraryPaths;
        libraryPaths.reserve(m_libraryPathsArg.values().size());
        for (const auto &path : m_libraryPathsArg.values()) {
            libraryPaths << QString::fromLocal8Bit(path);
        }
        QCoreApplication::setLibraryPaths(libraryPaths);
    }
}
}