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

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

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

class MidiInCollector
{
public:
    MidiInCollector (MidiInput* const input_,
                     MidiInputCallback& callback_)
        : deviceHandle (0),
          input (input_),
          callback (callback_),
          concatenator (4096),
          isStarted (false),
          startTime (0)
    {
    }

    ~MidiInCollector()
    {
        stop();

        if (deviceHandle != 0)
        {
            for (int count = 5; --count >= 0;)
            {
                if (midiInClose (deviceHandle) == MMSYSERR_NOERROR)
                    break;

                Sleep (20);
            }
        }
    }

    //==============================================================================
    void handleMessage (const uint8* bytes, const uint32 timeStamp)
    {
        if (bytes[0] >= 0x80 && isStarted)
        {
            concatenator.pushMidiData (bytes, MidiMessage::getMessageLengthFromFirstByte (bytes[0]),
                                       convertTimeStamp (timeStamp), input, callback);
            writeFinishedBlocks();
        }
    }

    void handleSysEx (MIDIHDR* const hdr, const uint32 timeStamp)
    {
        if (isStarted && hdr->dwBytesRecorded > 0)
        {
            concatenator.pushMidiData (hdr->lpData, (int) hdr->dwBytesRecorded,
                                       convertTimeStamp (timeStamp), input, callback);
            writeFinishedBlocks();
        }
    }

    void start()
    {
        if (deviceHandle != 0 && ! isStarted)
        {
            activeMidiCollectors.addIfNotAlreadyThere (this);

            for (int i = 0; i < (int) numHeaders; ++i)
            {
                headers[i].prepare (deviceHandle);
                headers[i].write (deviceHandle);
            }

            startTime = Time::getMillisecondCounterHiRes();
            MMRESULT res = midiInStart (deviceHandle);

            if (res == MMSYSERR_NOERROR)
            {
                concatenator.reset();
                isStarted = true;
            }
            else
            {
                unprepareAllHeaders();
            }
        }
    }

    void stop()
    {
        if (isStarted)
        {
            isStarted = false;
            midiInReset (deviceHandle);
            midiInStop (deviceHandle);
            activeMidiCollectors.removeFirstMatchingValue (this);
            unprepareAllHeaders();
            concatenator.reset();
        }
    }

    static void CALLBACK midiInCallback (HMIDIIN, UINT uMsg, DWORD_PTR dwInstance,
                                         DWORD_PTR midiMessage, DWORD_PTR timeStamp)
    {
        MidiInCollector* const collector = reinterpret_cast<MidiInCollector*> (dwInstance);

        if (activeMidiCollectors.contains (collector))
        {
            if (uMsg == MIM_DATA)
                collector->handleMessage ((const uint8*) &midiMessage, (uint32) timeStamp);
            else if (uMsg == MIM_LONGDATA)
                collector->handleSysEx ((MIDIHDR*) midiMessage, (uint32) timeStamp);
        }
    }

    HMIDIIN deviceHandle;

private:
    static Array <MidiInCollector*, CriticalSection> activeMidiCollectors;

    MidiInput* input;
    MidiInputCallback& callback;
    MidiDataConcatenator concatenator;
    bool volatile isStarted;
    double startTime;

    class MidiHeader
    {
    public:
        MidiHeader() {}

        void prepare (HMIDIIN device)
        {
            zerostruct (hdr);
            hdr.lpData = data;
            hdr.dwBufferLength = (DWORD) numElementsInArray (data);

            midiInPrepareHeader (device, &hdr, sizeof (hdr));
        }

        void unprepare (HMIDIIN device)
        {
            if ((hdr.dwFlags & WHDR_DONE) != 0)
            {
                int c = 10;
                while (--c >= 0 && midiInUnprepareHeader (device, &hdr, sizeof (hdr)) == MIDIERR_STILLPLAYING)
                    Thread::sleep (20);

                jassert (c >= 0);
            }
        }

        void write (HMIDIIN device)
        {
            hdr.dwBytesRecorded = 0;
            midiInAddBuffer (device, &hdr, sizeof (hdr));
        }

        void writeIfFinished (HMIDIIN device)
        {
            if ((hdr.dwFlags & WHDR_DONE) != 0)
                write (device);
        }

    private:
        MIDIHDR hdr;
        char data [256];

        JUCE_DECLARE_NON_COPYABLE (MidiHeader)
    };

    enum { numHeaders = 32 };
    MidiHeader headers [numHeaders];

    void writeFinishedBlocks()
    {
        for (int i = 0; i < (int) numHeaders; ++i)
            headers[i].writeIfFinished (deviceHandle);
    }

    void unprepareAllHeaders()
    {
        for (int i = 0; i < (int) numHeaders; ++i)
            headers[i].unprepare (deviceHandle);
    }

    double convertTimeStamp (uint32 timeStamp)
    {
        double t = startTime + timeStamp;

        const double now = Time::getMillisecondCounterHiRes();
        if (t > now)
        {
            if (t > now + 2.0)
                startTime -= 1.0;

            t = now;
        }

        return t * 0.001;
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MidiInCollector)
};

Array <MidiInCollector*, CriticalSection> MidiInCollector::activeMidiCollectors;


//==============================================================================
StringArray MidiInput::getDevices()
{
    StringArray s;
    const UINT num = midiInGetNumDevs();

    for (UINT i = 0; i < num; ++i)
    {
        MIDIINCAPS mc = { 0 };

        if (midiInGetDevCaps (i, &mc, sizeof (mc)) == MMSYSERR_NOERROR)
            s.add (String (mc.szPname, sizeof (mc.szPname)));
    }

    return s;
}

int MidiInput::getDefaultDeviceIndex()
{
    return 0;
}

MidiInput* MidiInput::openDevice (const int index, MidiInputCallback* const callback)
{
    if (callback == nullptr)
        return nullptr;

    UINT deviceId = MIDI_MAPPER;
    int n = 0;
    String name;

    const UINT num = midiInGetNumDevs();

    for (UINT i = 0; i < num; ++i)
    {
        MIDIINCAPS mc = { 0 };

        if (midiInGetDevCaps (i, &mc, sizeof (mc)) == MMSYSERR_NOERROR)
        {
            if (index == n)
            {
                deviceId = i;
                name = String (mc.szPname, (size_t) numElementsInArray (mc.szPname));
                break;
            }

            ++n;
        }
    }

    ScopedPointer<MidiInput> in (new MidiInput (name));
    ScopedPointer<MidiInCollector> collector (new MidiInCollector (in, *callback));

    HMIDIIN h;
    MMRESULT err = midiInOpen (&h, deviceId,
                               (DWORD_PTR) &MidiInCollector::midiInCallback,
                               (DWORD_PTR) (MidiInCollector*) collector,
                               CALLBACK_FUNCTION);

    if (err == MMSYSERR_NOERROR)
    {
        collector->deviceHandle = h;
        in->internal = collector.release();
        return in.release();
    }

    return nullptr;
}

MidiInput::MidiInput (const String& name_)
    : name (name_),
      internal (0)
{
}

MidiInput::~MidiInput()
{
    delete static_cast<MidiInCollector*> (internal);
}

void MidiInput::start()     { static_cast<MidiInCollector*> (internal)->start(); }
void MidiInput::stop()      { static_cast<MidiInCollector*> (internal)->stop(); }


//==============================================================================
struct MidiOutHandle
{
    int refCount;
    UINT deviceId;
    HMIDIOUT handle;

    static Array<MidiOutHandle*> activeHandles;

private:
    JUCE_LEAK_DETECTOR (MidiOutHandle)
};

Array<MidiOutHandle*> MidiOutHandle::activeHandles;

//==============================================================================
StringArray MidiOutput::getDevices()
{
    StringArray s;
    const UINT num = midiOutGetNumDevs();

    for (UINT i = 0; i < num; ++i)
    {
        MIDIOUTCAPS mc = { 0 };

        if (midiOutGetDevCaps (i, &mc, sizeof (mc)) == MMSYSERR_NOERROR)
            s.add (String (mc.szPname, sizeof (mc.szPname)));
    }

    return s;
}

int MidiOutput::getDefaultDeviceIndex()
{
    const UINT num = midiOutGetNumDevs();
    int n = 0;

    for (UINT i = 0; i < num; ++i)
    {
        MIDIOUTCAPS mc = { 0 };

        if (midiOutGetDevCaps (i, &mc, sizeof (mc)) == MMSYSERR_NOERROR)
        {
            if ((mc.wTechnology & MOD_MAPPER) != 0)
                return n;

             ++n;
        }
    }

    return 0;
}

MidiOutput* MidiOutput::openDevice (int index)
{
    UINT deviceId = MIDI_MAPPER;
    const UINT num = midiOutGetNumDevs();
    int n = 0;
    String deviceName;

    for (UINT i = 0; i < num; ++i)
    {
        MIDIOUTCAPS mc = { 0 };

        if (midiOutGetDevCaps (i, &mc, sizeof (mc)) == MMSYSERR_NOERROR)
        {
            String name = String (mc.szPname, sizeof (mc.szPname));

            // use the microsoft sw synth as a default - best not to allow deviceId
            // to be MIDI_MAPPER, or else device sharing breaks
            if (name.containsIgnoreCase ("microsoft"))
                deviceId = i;

            if (index == n)
            {
                deviceName = name;
                deviceId = i;
                break;
            }

            ++n;
        }
    }

    for (int i = MidiOutHandle::activeHandles.size(); --i >= 0;)
    {
        MidiOutHandle* const han = MidiOutHandle::activeHandles.getUnchecked(i);

        if (han->deviceId == deviceId)
        {
            han->refCount++;

            MidiOutput* const out = new MidiOutput (deviceName);
            out->internal = han;
            return out;
        }
    }

    for (int i = 4; --i >= 0;)
    {
        HMIDIOUT h = 0;
        MMRESULT res = midiOutOpen (&h, deviceId, 0, 0, CALLBACK_NULL);

        if (res == MMSYSERR_NOERROR)
        {
            MidiOutHandle* const han = new MidiOutHandle();
            han->deviceId = deviceId;
            han->refCount = 1;
            han->handle = h;
            MidiOutHandle::activeHandles.add (han);

            MidiOutput* const out = new MidiOutput (deviceName);
            out->internal = han;
            return out;
        }
        else if (res == MMSYSERR_ALLOCATED)
        {
            Sleep (100);
        }
        else
        {
            break;
        }
    }

    return nullptr;
}

MidiOutput::~MidiOutput()
{
    stopBackgroundThread();

    MidiOutHandle* const h = static_cast<MidiOutHandle*> (internal);

    if (MidiOutHandle::activeHandles.contains (h) && --(h->refCount) == 0)
    {
        midiOutClose (h->handle);
        MidiOutHandle::activeHandles.removeFirstMatchingValue (h);
        delete h;
    }
}

void MidiOutput::sendMessageNow (const MidiMessage& message)
{
    const MidiOutHandle* const handle = static_cast<const MidiOutHandle*> (internal);

    if (message.getRawDataSize() > 3 || message.isSysEx())
    {
        MIDIHDR h = { 0 };

        h.lpData = (char*) message.getRawData();
        h.dwBytesRecorded = h.dwBufferLength  = (DWORD) message.getRawDataSize();

        if (midiOutPrepareHeader (handle->handle, &h, sizeof (MIDIHDR)) == MMSYSERR_NOERROR)
        {
            MMRESULT res = midiOutLongMsg (handle->handle, &h, sizeof (MIDIHDR));

            if (res == MMSYSERR_NOERROR)
            {
                while ((h.dwFlags & MHDR_DONE) == 0)
                    Sleep (1);

                int count = 500; // 1 sec timeout

                while (--count >= 0)
                {
                    res = midiOutUnprepareHeader (handle->handle, &h, sizeof (MIDIHDR));

                    if (res == MIDIERR_STILLPLAYING)
                        Sleep (2);
                    else
                        break;
                }
            }
        }
    }
    else
    {
        for (int i = 0; i < 50; ++i)
        {
            if (midiOutShortMsg (handle->handle, *(unsigned int*) message.getRawData()) != MIDIERR_NOTREADY)
                break;

            Sleep (1);
        }
    }
}
