#include "qhotkey.h"
#include "qhotkey_p.h"
#include <qt_windows.h>
#include <QDebug>

#define HKEY_ID(nativeShortcut) (((nativeShortcut.key ^ (nativeShortcut.modifier << 8)) & 0x0FFF) | 0x7000)

class QHotkeyPrivateWin : public QHotkeyPrivate
{
public:
    // QAbstractNativeEventFilter interface
    bool nativeEventFilter(const QByteArray &eventType, void *message, long *result) Q_DECL_OVERRIDE;

protected:
    // QHotkeyPrivate interface
    quint32 nativeKeycode(Qt::Key keycode, bool &ok) Q_DECL_OVERRIDE;
    quint32 nativeModifiers(Qt::KeyboardModifiers modifiers, bool &ok) Q_DECL_OVERRIDE;
    bool registerShortcut(QHotkey::NativeShortcut shortcut) Q_DECL_OVERRIDE;
    bool unregisterShortcut(QHotkey::NativeShortcut shortcut) Q_DECL_OVERRIDE;

private:
    static QString formatWinError(DWORD winError);
};
NATIVE_INSTANCE(QHotkeyPrivateWin)

bool QHotkeyPrivateWin::nativeEventFilter(const QByteArray &eventType, void *message, long *result)
{
    Q_UNUSED(eventType);
    Q_UNUSED(result);

    MSG *msg = static_cast<MSG *>(message);
    if (msg->message == WM_HOTKEY) {
        this->activateShortcut(QHotkey::NativeShortcut(HIWORD(msg->lParam), LOWORD(msg->lParam)));
    }

    return false;
}

quint32 QHotkeyPrivateWin::nativeKeycode(Qt::Key keycode, bool &ok)
{
    ok = true;
    if (keycode <= 0xFFFF) { //Try to obtain the key from it's "character"
        const SHORT vKey = VkKeyScanW(keycode);
        if (vKey > -1) {
            return LOBYTE(vKey);
        }
    }

    //find key from switch/case --> Only finds a very small subset of keys
    switch (keycode) {
        case Qt::Key_Escape:
            return VK_ESCAPE;
        case Qt::Key_Tab:
        case Qt::Key_Backtab:
            return VK_TAB;
        case Qt::Key_Backspace:
            return VK_BACK;
        case Qt::Key_Return:
        case Qt::Key_Enter:
            return VK_RETURN;
        case Qt::Key_Insert:
            return VK_INSERT;
        case Qt::Key_Delete:
            return VK_DELETE;
        case Qt::Key_Pause:
            return VK_PAUSE;
        case Qt::Key_Print:
            return VK_PRINT;
        case Qt::Key_Clear:
            return VK_CLEAR;
        case Qt::Key_Home:
            return VK_HOME;
        case Qt::Key_End:
            return VK_END;
        case Qt::Key_Left:
            return VK_LEFT;
        case Qt::Key_Up:
            return VK_UP;
        case Qt::Key_Right:
            return VK_RIGHT;
        case Qt::Key_Down:
            return VK_DOWN;
        case Qt::Key_PageUp:
            return VK_PRIOR;
        case Qt::Key_PageDown:
            return VK_NEXT;
        case Qt::Key_CapsLock:
            return VK_CAPITAL;
        case Qt::Key_NumLock:
            return VK_NUMLOCK;
        case Qt::Key_ScrollLock:
            return VK_SCROLL;

        case Qt::Key_F1:
            return VK_F1;
        case Qt::Key_F2:
            return VK_F2;
        case Qt::Key_F3:
            return VK_F3;
        case Qt::Key_F4:
            return VK_F4;
        case Qt::Key_F5:
            return VK_F5;
        case Qt::Key_F6:
            return VK_F6;
        case Qt::Key_F7:
            return VK_F7;
        case Qt::Key_F8:
            return VK_F8;
        case Qt::Key_F9:
            return VK_F9;
        case Qt::Key_F10:
            return VK_F10;
        case Qt::Key_F11:
            return VK_F11;
        case Qt::Key_F12:
            return VK_F12;
        case Qt::Key_F13:
            return VK_F13;
        case Qt::Key_F14:
            return VK_F14;
        case Qt::Key_F15:
            return VK_F15;
        case Qt::Key_F16:
            return VK_F16;
        case Qt::Key_F17:
            return VK_F17;
        case Qt::Key_F18:
            return VK_F18;
        case Qt::Key_F19:
            return VK_F19;
        case Qt::Key_F20:
            return VK_F20;
        case Qt::Key_F21:
            return VK_F21;
        case Qt::Key_F22:
            return VK_F22;
        case Qt::Key_F23:
            return VK_F23;
        case Qt::Key_F24:
            return VK_F24;

        case Qt::Key_Menu:
            return VK_APPS;
        case Qt::Key_Help:
            return VK_HELP;
        case Qt::Key_MediaNext:
            return VK_MEDIA_NEXT_TRACK;
        case Qt::Key_MediaPrevious:
            return VK_MEDIA_PREV_TRACK;
        case Qt::Key_MediaPlay:
            return VK_MEDIA_PLAY_PAUSE;
        case Qt::Key_MediaStop:
            return VK_MEDIA_STOP;
        case Qt::Key_VolumeDown:
            return VK_VOLUME_DOWN;
        case Qt::Key_VolumeUp:
            return VK_VOLUME_UP;
        case Qt::Key_VolumeMute:
            return VK_VOLUME_MUTE;
        case Qt::Key_Mode_switch:
            return VK_MODECHANGE;
        case Qt::Key_Select:
            return VK_SELECT;
        case Qt::Key_Printer:
            return VK_PRINT;
        case Qt::Key_Execute:
            return VK_EXECUTE;
        case Qt::Key_Sleep:
            return VK_SLEEP;
        case Qt::Key_Period:
            return VK_DECIMAL;
        case Qt::Key_Play:
            return VK_PLAY;
        case Qt::Key_Cancel:
            return VK_CANCEL;

        case Qt::Key_Forward:
            return VK_BROWSER_FORWARD;
        case Qt::Key_Refresh:
            return VK_BROWSER_REFRESH;
        case Qt::Key_Stop:
            return VK_BROWSER_STOP;
        case Qt::Key_Search:
            return VK_BROWSER_SEARCH;
        case Qt::Key_Favorites:
            return VK_BROWSER_FAVORITES;
        case Qt::Key_HomePage:
            return VK_BROWSER_HOME;

        case Qt::Key_LaunchMail:
            return VK_LAUNCH_MAIL;
        case Qt::Key_LaunchMedia:
            return VK_LAUNCH_MEDIA_SELECT;
        case Qt::Key_Launch0:
            return VK_LAUNCH_APP1;
        case Qt::Key_Launch1:
            return VK_LAUNCH_APP2;

        case Qt::Key_Massyo:
            return VK_OEM_FJ_MASSHOU;
        case Qt::Key_Touroku:
            return VK_OEM_FJ_TOUROKU;

        default:
            ok = false;
            return 0;
    }
}

quint32 QHotkeyPrivateWin::nativeModifiers(Qt::KeyboardModifiers modifiers, bool &ok)
{
    quint32 nMods = 0;
    if (modifiers & Qt::ShiftModifier) {
        nMods |= MOD_SHIFT;
    }
    if (modifiers & Qt::ControlModifier) {
        nMods |= MOD_CONTROL;
    }
    if (modifiers & Qt::AltModifier) {
        nMods |= MOD_ALT;
    }
    if (modifiers & Qt::MetaModifier) {
        nMods |= MOD_WIN;
    }
    ok = true;
    return nMods;
}

bool QHotkeyPrivateWin::registerShortcut(QHotkey::NativeShortcut shortcut)
{
    BOOL ok = RegisterHotKey(NULL,
                             HKEY_ID(shortcut),
                             shortcut.modifier,
                             shortcut.key);
    if (ok) {
        return true;
    } else {
        qDebug() << "Failed to register hotkey. Error:"
                 << qPrintable(QHotkeyPrivateWin::formatWinError(::GetLastError()));
        return false;
    }
}

bool QHotkeyPrivateWin::unregisterShortcut(QHotkey::NativeShortcut shortcut)
{
    BOOL ok = UnregisterHotKey(NULL, HKEY_ID(shortcut));
    if (ok) {
        return true;
    } else {
        qDebug() << "Failed to unregister hotkey. Error:"
                 << qPrintable(QHotkeyPrivateWin::formatWinError(::GetLastError()));
        return false;
    }
}

QString QHotkeyPrivateWin::formatWinError(DWORD winError)
{
    wchar_t *buffer = NULL;
    DWORD num = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
                               NULL,
                               winError,
                               0,
                               (LPWSTR)&buffer,
                               0,
                               NULL);
    if (buffer) {
        QString res = QString::fromWCharArray(buffer, num);
        LocalFree(buffer);
        return res;
    } else {
        return QString();
    }
}