#include "qhotkey.h"
#include "qhotkey_p.h"
#include <Carbon/Carbon.h>
#include <QDebug>

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

    static OSStatus hotkeyEventHandler(EventHandlerCallRef nextHandler, EventRef event, void *data);

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 bool isHotkeyHandlerRegistered;
    static QHash<QHotkey::NativeShortcut, EventHotKeyRef> hotkeyRefs;
};
NATIVE_INSTANCE(QHotkeyPrivateMac)

bool QHotkeyPrivateMac::isHotkeyHandlerRegistered = false;
QHash<QHotkey::NativeShortcut, EventHotKeyRef> QHotkeyPrivateMac::hotkeyRefs;

bool QHotkeyPrivateMac::nativeEventFilter(const QByteArray &eventType, void *message, long *result)
{
    Q_UNUSED(eventType);
    Q_UNUSED(message);
    Q_UNUSED(result);
    return false;
}

quint32 QHotkeyPrivateMac::nativeKeycode(Qt::Key keycode, bool &ok)
{
    // Constants found in NSEvent.h from AppKit.framework
    ok = true;
    switch (keycode) {
        case Qt::Key_Return:
            return kVK_Return;
        case Qt::Key_Enter:
            return kVK_ANSI_KeypadEnter;
        case Qt::Key_Tab:
            return kVK_Tab;
        case Qt::Key_Space:
            return kVK_Space;
        case Qt::Key_Backspace:
            return kVK_Delete;
        case Qt::Key_Escape:
            return kVK_Escape;
        case Qt::Key_CapsLock:
            return kVK_CapsLock;
        case Qt::Key_Option:
            return kVK_Option;
        case Qt::Key_F17:
            return kVK_F17;
        case Qt::Key_VolumeUp:
            return kVK_VolumeUp;
        case Qt::Key_VolumeDown:
            return kVK_VolumeDown;
        case Qt::Key_F18:
            return kVK_F18;
        case Qt::Key_F19:
            return kVK_F19;
        case Qt::Key_F20:
            return kVK_F20;
        case Qt::Key_F5:
            return kVK_F5;
        case Qt::Key_F6:
            return kVK_F6;
        case Qt::Key_F7:
            return kVK_F7;
        case Qt::Key_F3:
            return kVK_F3;
        case Qt::Key_F8:
            return kVK_F8;
        case Qt::Key_F9:
            return kVK_F9;
        case Qt::Key_F11:
            return kVK_F11;
        case Qt::Key_F13:
            return kVK_F13;
        case Qt::Key_F16:
            return kVK_F16;
        case Qt::Key_F14:
            return kVK_F14;
        case Qt::Key_F10:
            return kVK_F10;
        case Qt::Key_F12:
            return kVK_F12;
        case Qt::Key_F15:
            return kVK_F15;
        case Qt::Key_Help:
            return kVK_Help;
        case Qt::Key_Home:
            return kVK_Home;
        case Qt::Key_PageUp:
            return kVK_PageUp;
        case Qt::Key_Delete:
            return kVK_ForwardDelete;
        case Qt::Key_F4:
            return kVK_F4;
        case Qt::Key_End:
            return kVK_End;
        case Qt::Key_F2:
            return kVK_F2;
        case Qt::Key_PageDown:
            return kVK_PageDown;
        case Qt::Key_F1:
            return kVK_F1;
        case Qt::Key_Left:
            return kVK_LeftArrow;
        case Qt::Key_Right:
            return kVK_RightArrow;
        case Qt::Key_Down:
            return kVK_DownArrow;
        case Qt::Key_Up:
            return kVK_UpArrow;
        default:
            ok = false;
            break;
    }

    UTF16Char ch = keycode;

    CFDataRef currentLayoutData;
    TISInputSourceRef currentKeyboard = TISCopyCurrentKeyboardInputSource();

    if (currentKeyboard == NULL) {
        return 0;
    }

    currentLayoutData = (CFDataRef)TISGetInputSourceProperty(currentKeyboard, kTISPropertyUnicodeKeyLayoutData);
    CFRelease(currentKeyboard);
    if (currentLayoutData == NULL) {
        return 0;
    }

    UCKeyboardLayout *header = (UCKeyboardLayout *)CFDataGetBytePtr(currentLayoutData);
    UCKeyboardTypeHeader *table = header->keyboardTypeList;

    uint8_t *data = (uint8_t *)header;
    for (quint32 i = 0; i < header->keyboardTypeCount; i++) {
        UCKeyStateRecordsIndex *stateRec = 0;
        if (table[i].keyStateRecordsIndexOffset != 0) {
            stateRec = reinterpret_cast<UCKeyStateRecordsIndex *>(data + table[i].keyStateRecordsIndexOffset);
            if (stateRec->keyStateRecordsIndexFormat != kUCKeyStateRecordsIndexFormat) {
                stateRec = 0;
            }
        }

        UCKeyToCharTableIndex *charTable = reinterpret_cast<UCKeyToCharTableIndex *>(data + table[i].keyToCharTableIndexOffset);
        if (charTable->keyToCharTableIndexFormat != kUCKeyToCharTableIndexFormat) {
            continue;
        }

        for (quint32 j = 0; j < charTable->keyToCharTableCount; j++) {
            UCKeyOutput *keyToChar = reinterpret_cast<UCKeyOutput *>(data + charTable->keyToCharTableOffsets[j]);
            for (quint32 k = 0; k < charTable->keyToCharTableSize; k++) {
                if (keyToChar[k] & kUCKeyOutputTestForIndexMask) {
                    long idx = keyToChar[k] & kUCKeyOutputGetIndexMask;
                    if (stateRec && idx < stateRec->keyStateRecordCount) {
                        UCKeyStateRecord *rec = reinterpret_cast<UCKeyStateRecord *>(data + stateRec->keyStateRecordOffsets[idx]);
                        if (rec->stateZeroCharData == ch) {
                            ok = true;
                            return k;
                        }
                    }
                } else if (!(keyToChar[k] & kUCKeyOutputSequenceIndexMask) && keyToChar[k] < 0xFFFE) {
                    if (keyToChar[k] == ch) {
                        ok = true;
                        return k;
                    }
                }
            }
        }
    }
    return 0;
}

quint32 QHotkeyPrivateMac::nativeModifiers(Qt::KeyboardModifiers modifiers, bool &ok)
{
    quint32 nMods = 0;
    if (modifiers & Qt::ShiftModifier) {
        nMods |= shiftKey;
    }
    if (modifiers & Qt::ControlModifier) {
        nMods |= cmdKey;
    }
    if (modifiers & Qt::AltModifier) {
        nMods |= optionKey;
    }
    if (modifiers & Qt::MetaModifier) {
        nMods |= controlKey;
    }
    if (modifiers & Qt::KeypadModifier) {
        nMods |= kEventKeyModifierNumLockMask;
    }
    ok = true;
    return nMods;
}

bool QHotkeyPrivateMac::registerShortcut(QHotkey::NativeShortcut shortcut)
{
    if (!this->isHotkeyHandlerRegistered) {
        EventTypeSpec eventSpec;
        eventSpec.eventClass = kEventClassKeyboard;
        eventSpec.eventKind = kEventHotKeyPressed;
        InstallApplicationEventHandler(&QHotkeyPrivateMac::hotkeyEventHandler, 1, &eventSpec, NULL, NULL);
    }

    EventHotKeyID hkeyID;
    hkeyID.signature = shortcut.key;
    hkeyID.id = shortcut.modifier;

    EventHotKeyRef eventRef = 0;
    OSStatus status = RegisterEventHotKey(shortcut.key,
                                          shortcut.modifier,
                                          hkeyID,
                                          GetApplicationEventTarget(),
                                          0,
                                          &eventRef);
    if (status != noErr) {
        qDebug() << "Failed to register hotkey. Error:" << status;
        return false;
    } else {
        this->hotkeyRefs.insert(shortcut, eventRef);
        return true;
    }
}

bool QHotkeyPrivateMac::unregisterShortcut(QHotkey::NativeShortcut shortcut)
{
    EventHotKeyRef eventRef = QHotkeyPrivateMac::hotkeyRefs.value(shortcut);
    OSStatus status = UnregisterEventHotKey(eventRef);
    if (status != noErr) {
        qDebug() << "Failed to unregister hotkey. Error:" << status;
        return false;
    } else {
        this->hotkeyRefs.remove(shortcut);
        return true;
    }
}

OSStatus QHotkeyPrivateMac::hotkeyEventHandler(EventHandlerCallRef nextHandler, EventRef event, void *data)
{
    Q_UNUSED(nextHandler);
    Q_UNUSED(data);

    if (GetEventClass(event) == kEventClassKeyboard &&
        GetEventKind(event) == kEventHotKeyPressed) {
        EventHotKeyID hkeyID;
        GetEventParameter(event,
                          kEventParamDirectObject,
                          typeEventHotKeyID,
                          NULL,
                          sizeof(EventHotKeyID),
                          NULL,
                          &hkeyID);
        hotkeyPrivate->activateShortcut(QHotkey::NativeShortcut(hkeyID.signature, hkeyID.id));
    }

    return noErr;
}