/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

extern HWND juce_messageWindowHandle;

#if JUCE_MODULE_AVAILABLE_juce_gui_extra
 LRESULT juce_offerEventToActiveXControl (::MSG&);
#endif

using CheckEventBlockedByModalComps = bool (*)(const MSG&);
CheckEventBlockedByModalComps isEventBlockedByModalComps = nullptr;

using SettingChangeCallbackFunc = void (*)(void);
SettingChangeCallbackFunc settingChangeCallback = nullptr;

//==============================================================================
class InternalMessageQueue
{
public:
    InternalMessageQueue()
    {
        messageWindow = std::make_unique<HiddenMessageWindow> (messageWindowName, (WNDPROC) messageWndProc);
        juce_messageWindowHandle = messageWindow->getHWND();
    }

    ~InternalMessageQueue()
    {
        juce_messageWindowHandle = nullptr;
        clearSingletonInstance();
    }

    JUCE_DECLARE_SINGLETON_INLINE (InternalMessageQueue, false)

    //==============================================================================
    void broadcastMessage (const String& message)
    {
        auto localCopy = message;

        Array<HWND> windows;
        EnumWindows (&broadcastEnumWindowProc, (LPARAM) &windows);

        for (int i = windows.size(); --i >= 0;)
        {
            COPYDATASTRUCT data;
            data.dwData = broadcastMessageMagicNumber;
            data.cbData = (DWORD) (((size_t) localCopy.length() + 1) * sizeof (CharPointer_UTF32::CharType));
            data.lpData = (void*) localCopy.toUTF32().getAddress();

            DWORD_PTR result;
            SendMessageTimeout (windows.getUnchecked (i), WM_COPYDATA,
                                (WPARAM) juce_messageWindowHandle,
                                (LPARAM) &data,
                                SMTO_BLOCK | SMTO_ABORTIFHUNG, 8000, &result);
        }
    }

    void postMessage (MessageManager::MessageBase* message)
    {
        bool shouldTriggerMessageQueueDispatch = false;

        {
            const ScopedLock sl (lock);

            shouldTriggerMessageQueueDispatch = messageQueue.isEmpty();
            messageQueue.add (message);
        }

        if (! shouldTriggerMessageQueueDispatch)
            return;

        if (detail::RunningInUnity::state)
        {
            SendNotifyMessage (juce_messageWindowHandle, customMessageID, 0, 0);
            return;
        }

        PostMessage (juce_messageWindowHandle, customMessageID, 0, 0);
    }

    bool dispatchNextMessage (bool returnIfNoPendingMessages)
    {
        MSG m;

        if (returnIfNoPendingMessages && ! PeekMessage (&m, nullptr, 0, 0, PM_NOREMOVE))
            return false;

        if (GetMessage (&m, nullptr, 0, 0) >= 0)
        {
           #if JUCE_MODULE_AVAILABLE_juce_gui_extra
            if (juce_offerEventToActiveXControl (m) != S_FALSE)
                return true;
           #endif

            if (m.message == customMessageID && m.hwnd == juce_messageWindowHandle)
            {
                dispatchMessages();
            }
            else if (m.message == WM_QUIT)
            {
                if (auto* app = JUCEApplicationBase::getInstance())
                    app->systemRequestedQuit();
            }
            else if (isEventBlockedByModalComps == nullptr || ! isEventBlockedByModalComps (m))
            {
                if ((m.message == WM_LBUTTONDOWN || m.message == WM_RBUTTONDOWN)
                      && ! JuceWindowIdentifier::isJUCEWindow (m.hwnd))
                {
                    // if it's someone else's window being clicked on, and the focus is
                    // currently on a juce window, pass the kb focus over..
                    auto currentFocus = GetFocus();

                    if (currentFocus == nullptr || JuceWindowIdentifier::isJUCEWindow (currentFocus))
                        SetFocus (m.hwnd);
                }

                TranslateMessage (&m);
                DispatchMessage (&m);
            }
        }

        return true;
    }

private:
    //==============================================================================
    static LRESULT CALLBACK messageWndProc (HWND h, UINT message, WPARAM wParam, LPARAM lParam) noexcept
    {
        if (h == juce_messageWindowHandle)
        {
            if (message == customMessageID)
            {
                if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
                    queue->dispatchMessages();

                return 0;
            }

            if (message == WM_COPYDATA)
            {
                handleBroadcastMessage (reinterpret_cast<const COPYDATASTRUCT*> (lParam));
                return 0;
            }

            if (message == WM_SETTINGCHANGE)
                NullCheckedInvocation::invoke (settingChangeCallback);
        }

        return DefWindowProc (h, message, wParam, lParam);
    }

    static BOOL CALLBACK broadcastEnumWindowProc (HWND hwnd, LPARAM lParam)
    {
        if (hwnd != juce_messageWindowHandle)
        {
            TCHAR windowName[64] = { 0 }; // no need to read longer strings than this
            GetWindowText (hwnd, windowName, 63);

            if (String (windowName) == messageWindowName)
                reinterpret_cast<Array<HWND>*> (lParam)->add (hwnd);
        }

        return TRUE;
    }

    static void dispatchMessage (MessageManager::MessageBase* message)
    {
        JUCE_TRY
        {
            message->messageCallback();
        }
        JUCE_CATCH_EXCEPTION

        message->decReferenceCount();
    }

    static void handleBroadcastMessage (const COPYDATASTRUCT* data)
    {
        if (data != nullptr && data->dwData == broadcastMessageMagicNumber)
        {
            struct BroadcastMessage final : public CallbackMessage
            {
                BroadcastMessage (CharPointer_UTF32 text, size_t length) : message (text, length) {}
                void messageCallback() override { MessageManager::getInstance()->deliverBroadcastMessage (message); }

                String message;
            };

            (new BroadcastMessage (CharPointer_UTF32 ((const CharPointer_UTF32::CharType*) data->lpData),
                                   data->cbData / sizeof (CharPointer_UTF32::CharType)))
                ->post();
        }
    }

    void dispatchMessages()
    {
        ReferenceCountedArray<MessageManager::MessageBase> messagesToDispatch;

        {
            const ScopedLock sl (lock);

            if (messageQueue.isEmpty())
                return;

            messagesToDispatch.swapWith (messageQueue);
        }

        for (int i = 0; i < messagesToDispatch.size(); ++i)
        {
            auto message = messagesToDispatch.getUnchecked (i);
            message->incReferenceCount();
            dispatchMessage (message.get());
        }
    }

    //==============================================================================
    static constexpr unsigned int customMessageID = WM_USER + 123;
    static constexpr unsigned int broadcastMessageMagicNumber = 0xc403;
    static const TCHAR messageWindowName[];

    std::unique_ptr<HiddenMessageWindow> messageWindow;

    CriticalSection lock;
    ReferenceCountedArray<MessageManager::MessageBase> messageQueue;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (InternalMessageQueue)
};

const TCHAR InternalMessageQueue::messageWindowName[] = _T("JUCEWindow");

//==============================================================================
namespace detail
{

bool dispatchNextMessageOnSystemQueue (bool returnIfNoPendingMessages)
{
    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
        return queue->dispatchNextMessage (returnIfNoPendingMessages);

    return false;
}

} // namespace detail

bool MessageManager::postMessageToSystemQueue (MessageManager::MessageBase* const message)
{
    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
    {
        queue->postMessage (message);
        return true;
    }

    return false;
}

void MessageManager::broadcastMessage (const String& value)
{
    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
        queue->broadcastMessage (value);
}

//==============================================================================
void MessageManager::doPlatformSpecificInitialisation()
{
    [[maybe_unused]] const auto result = OleInitialize (nullptr);
    InternalMessageQueue::getInstance();
}

void MessageManager::doPlatformSpecificShutdown()
{
    InternalMessageQueue::deleteInstance();
    OleUninitialize();
}

//==============================================================================
struct MountedVolumeListChangeDetector::Pimpl
{
    explicit Pimpl (MountedVolumeListChangeDetector& d)
        : owner (d)
    {
        File::findFileSystemRoots (lastVolumeList);
    }

    void systemDeviceChanged()
    {
        Array<File> newList;
        File::findFileSystemRoots (newList);

        if (std::exchange (lastVolumeList, newList) != newList)
            owner.mountedVolumeListChanged();
    }

    DeviceChangeDetector detector { L"MountedVolumeList", [this] { systemDeviceChanged(); } };
    MountedVolumeListChangeDetector& owner;
    Array<File> lastVolumeList;
};

MountedVolumeListChangeDetector::MountedVolumeListChangeDetector()  { pimpl.reset (new Pimpl (*this)); }
MountedVolumeListChangeDetector::~MountedVolumeListChangeDetector() {}

} // namespace juce
