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

   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.

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

//==============================================================================
#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD) \
 STATICMETHOD (getMinBufferSize,            "getMinBufferSize",             "(III)I") \
 STATICMETHOD (getNativeOutputSampleRate,   "getNativeOutputSampleRate",    "(I)I") \
 METHOD (constructor,   "<init>",   "(IIIIII)V") \
 METHOD (getState,      "getState", "()I") \
 METHOD (play,          "play",     "()V") \
 METHOD (stop,          "stop",     "()V") \
 METHOD (release,       "release",  "()V") \
 METHOD (flush,         "flush",    "()V") \
 METHOD (write,         "write",    "([SII)I") \

DECLARE_JNI_CLASS (AudioTrack, "android/media/AudioTrack");
#undef JNI_CLASS_MEMBERS

//==============================================================================
#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD) \
 STATICMETHOD (getMinBufferSize, "getMinBufferSize", "(III)I") \
 METHOD (constructor,       "<init>",           "(IIIII)V") \
 METHOD (getState,          "getState",         "()I") \
 METHOD (startRecording,    "startRecording",   "()V") \
 METHOD (stop,              "stop",             "()V") \
 METHOD (read,              "read",             "([SII)I") \
 METHOD (release,           "release",          "()V") \

DECLARE_JNI_CLASS (AudioRecord, "android/media/AudioRecord");
#undef JNI_CLASS_MEMBERS

//==============================================================================
enum
{
    CHANNEL_OUT_STEREO  = 12,
    CHANNEL_IN_STEREO   = 12,
    CHANNEL_IN_MONO     = 16,
    ENCODING_PCM_16BIT  = 2,
    STREAM_MUSIC        = 3,
    MODE_STREAM         = 1,
    STATE_UNINITIALIZED = 0
};

const char* const javaAudioTypeName = "Android Audio";

//==============================================================================
class AndroidAudioIODevice  : public AudioIODevice,
                              public Thread
{
public:
    //==============================================================================
    AndroidAudioIODevice (const String& deviceName)
        : AudioIODevice (deviceName, javaAudioTypeName),
          Thread ("audio"),
          minBufferSizeOut (0), minBufferSizeIn (0), callback (0), sampleRate (0),
          numClientInputChannels (0), numDeviceInputChannels (0), numDeviceInputChannelsAvailable (2),
          numClientOutputChannels (0), numDeviceOutputChannels (0),
          actualBufferSize (0), isRunning (false),
          inputChannelBuffer (1, 1),
          outputChannelBuffer (1, 1)
    {
        JNIEnv* env = getEnv();
        sampleRate = env->CallStaticIntMethod (AudioTrack, AudioTrack.getNativeOutputSampleRate, MODE_STREAM);

        minBufferSizeOut = (int) env->CallStaticIntMethod (AudioTrack,  AudioTrack.getMinBufferSize,  sampleRate, CHANNEL_OUT_STEREO, ENCODING_PCM_16BIT);
        minBufferSizeIn  = (int) env->CallStaticIntMethod (AudioRecord, AudioRecord.getMinBufferSize, sampleRate, CHANNEL_IN_STEREO,  ENCODING_PCM_16BIT);

        if (minBufferSizeIn <= 0)
        {
            minBufferSizeIn = env->CallStaticIntMethod (AudioRecord, AudioRecord.getMinBufferSize, sampleRate, CHANNEL_IN_MONO, ENCODING_PCM_16BIT);

            if (minBufferSizeIn > 0)
                numDeviceInputChannelsAvailable = 1;
            else
                numDeviceInputChannelsAvailable = 0;
        }

        DBG ("Audio device - min buffers: " << minBufferSizeOut << ", " << minBufferSizeIn << "; "
              << sampleRate << " Hz; input chans: " << numDeviceInputChannelsAvailable);
    }

    ~AndroidAudioIODevice()
    {
        close();
    }

    StringArray getOutputChannelNames() override
    {
        StringArray s;
        s.add ("Left");
        s.add ("Right");
        return s;
    }

    StringArray getInputChannelNames() override
    {
        StringArray s;

        if (numDeviceInputChannelsAvailable == 2)
        {
            s.add ("Left");
            s.add ("Right");
        }
        else if (numDeviceInputChannelsAvailable == 1)
        {
            s.add ("Audio Input");
        }

        return s;
    }

    Array<double> getAvailableSampleRates() override
    {
        Array<double> r;
        r.add ((double) sampleRate);
        return r;
    }

    Array<int> getAvailableBufferSizes() override
    {
        Array<int> b;
        int n = 16;

        for (int i = 0; i < 50; ++i)
        {
            b.add (n);
            n += n < 64 ? 16
                        : (n < 512 ? 32
                                   : (n < 1024 ? 64
                                               : (n < 2048 ? 128 : 256)));
        }

        return b;
    }

    int getDefaultBufferSize() override                 { return 2048; }

    String open (const BigInteger& inputChannels,
                 const BigInteger& outputChannels,
                 double requestedSampleRate,
                 int bufferSize) override
    {
        close();

        if (sampleRate != (int) requestedSampleRate)
            return "Sample rate not allowed";

        lastError.clear();
        int preferredBufferSize = (bufferSize <= 0) ? getDefaultBufferSize() : bufferSize;

        numDeviceInputChannels = 0;
        numDeviceOutputChannels = 0;

        activeOutputChans = outputChannels;
        activeOutputChans.setRange (2, activeOutputChans.getHighestBit(), false);
        numClientOutputChannels = activeOutputChans.countNumberOfSetBits();

        activeInputChans = inputChannels;
        activeInputChans.setRange (2, activeInputChans.getHighestBit(), false);
        numClientInputChannels = activeInputChans.countNumberOfSetBits();

        actualBufferSize = preferredBufferSize;
        inputChannelBuffer.setSize (2, actualBufferSize);
        inputChannelBuffer.clear();
        outputChannelBuffer.setSize (2, actualBufferSize);
        outputChannelBuffer.clear();

        JNIEnv* env = getEnv();

        if (numClientOutputChannels > 0)
        {
            numDeviceOutputChannels = 2;
            outputDevice = GlobalRef (env->NewObject (AudioTrack, AudioTrack.constructor,
                                                      STREAM_MUSIC, sampleRate, CHANNEL_OUT_STEREO, ENCODING_PCM_16BIT,
                                                      (jint) (minBufferSizeOut * numDeviceOutputChannels * sizeof (int16)), MODE_STREAM));

            int outputDeviceState = env->CallIntMethod (outputDevice, AudioTrack.getState);
            if (outputDeviceState > 0)
            {
                isRunning = true;
            }
            else
            {
                 // failed to open the device
                outputDevice.clear();
                lastError = "Error opening audio output device: android.media.AudioTrack failed with state = " + String (outputDeviceState);
            }
        }

        if (numClientInputChannels > 0 && numDeviceInputChannelsAvailable > 0)
        {
            if (! RuntimePermissions::isGranted (RuntimePermissions::recordAudio))
            {
                // If you hit this assert, you probably forgot to get RuntimePermissions::recordAudio
                // before trying to open an audio input device. This is not going to work!
                jassertfalse;

                inputDevice.clear();
                lastError = "Error opening audio input device: the app was not granted android.permission.RECORD_AUDIO";
            }
            else
            {
                numDeviceInputChannels = jmin (numClientInputChannels, numDeviceInputChannelsAvailable);
                inputDevice = GlobalRef (env->NewObject (AudioRecord, AudioRecord.constructor,
                                                         0 /* (default audio source) */, sampleRate,
                                                         numDeviceInputChannelsAvailable > 1 ? CHANNEL_IN_STEREO : CHANNEL_IN_MONO,
                                                         ENCODING_PCM_16BIT,
                                                         (jint) (minBufferSizeIn * numDeviceInputChannels * sizeof (int16))));

                int inputDeviceState = env->CallIntMethod (inputDevice, AudioRecord.getState);
                if (inputDeviceState > 0)
                {
                    isRunning = true;
                }
                else
                {
                     // failed to open the device
                    inputDevice.clear();
                    lastError = "Error opening audio input device: android.media.AudioRecord failed with state = " + String (inputDeviceState);
                }
            }
        }

        if (isRunning)
        {
            if (outputDevice != nullptr)
                env->CallVoidMethod (outputDevice, AudioTrack.play);

            if (inputDevice != nullptr)
                env->CallVoidMethod (inputDevice, AudioRecord.startRecording);

            startThread (8);
        }
        else
        {
            closeDevices();
        }

        return lastError;
    }

    void close() override
    {
        if (isRunning)
        {
            stopThread (2000);
            isRunning = false;
            closeDevices();
        }
    }

    int getOutputLatencyInSamples() override             { return (minBufferSizeOut * 3) / 4; }
    int getInputLatencyInSamples() override              { return (minBufferSizeIn * 3) / 4; }
    bool isOpen() override                               { return isRunning; }
    int getCurrentBufferSizeSamples() override           { return actualBufferSize; }
    int getCurrentBitDepth() override                    { return 16; }
    double getCurrentSampleRate() override               { return sampleRate; }
    BigInteger getActiveOutputChannels() const override  { return activeOutputChans; }
    BigInteger getActiveInputChannels() const override   { return activeInputChans; }
    String getLastError() override                       { return lastError; }
    bool isPlaying() override                            { return isRunning && callback != 0; }

    void start (AudioIODeviceCallback* newCallback) override
    {
        if (isRunning && callback != newCallback)
        {
            if (newCallback != nullptr)
                newCallback->audioDeviceAboutToStart (this);

            const ScopedLock sl (callbackLock);
            callback = newCallback;
        }
    }

    void stop() override
    {
        if (isRunning)
        {
            AudioIODeviceCallback* lastCallback;

            {
                const ScopedLock sl (callbackLock);
                lastCallback = callback;
                callback = nullptr;
            }

            if (lastCallback != nullptr)
                lastCallback->audioDeviceStopped();
        }
    }

    void run() override
    {
        JNIEnv* env = getEnv();
        jshortArray audioBuffer = env->NewShortArray (actualBufferSize * jmax (numDeviceOutputChannels, numDeviceInputChannels));

        while (! threadShouldExit())
        {
            if (inputDevice != nullptr)
            {
                jint numRead = env->CallIntMethod (inputDevice, AudioRecord.read, audioBuffer, 0, actualBufferSize * numDeviceInputChannels);

                if (numRead < actualBufferSize * numDeviceInputChannels)
                {
                    DBG ("Audio read under-run! " << numRead);
                }

                jshort* const src = env->GetShortArrayElements (audioBuffer, 0);

                for (int chan = 0; chan < inputChannelBuffer.getNumChannels(); ++chan)
                {
                    AudioData::Pointer <AudioData::Float32, AudioData::NativeEndian, AudioData::NonInterleaved, AudioData::NonConst> d (inputChannelBuffer.getWritePointer (chan));

                    if (chan < numDeviceInputChannels)
                    {
                        AudioData::Pointer <AudioData::Int16, AudioData::NativeEndian, AudioData::Interleaved, AudioData::Const> s (src + chan, numDeviceInputChannels);
                        d.convertSamples (s, actualBufferSize);
                    }
                    else
                    {
                        d.clearSamples (actualBufferSize);
                    }
                }

                env->ReleaseShortArrayElements (audioBuffer, src, 0);
            }

            if (threadShouldExit())
                break;

            {
                const ScopedLock sl (callbackLock);

                if (callback != nullptr)
                {
                    callback->audioDeviceIOCallback (inputChannelBuffer.getArrayOfReadPointers(), numClientInputChannels,
                                                     outputChannelBuffer.getArrayOfWritePointers(), numClientOutputChannels,
                                                     actualBufferSize);
                }
                else
                {
                    outputChannelBuffer.clear();
                }
            }

            if (outputDevice != nullptr)
            {
                if (threadShouldExit())
                    break;

                jshort* const dest = env->GetShortArrayElements (audioBuffer, 0);

                for (int chan = 0; chan < numDeviceOutputChannels; ++chan)
                {
                    AudioData::Pointer <AudioData::Int16, AudioData::NativeEndian, AudioData::Interleaved, AudioData::NonConst> d (dest + chan, numDeviceOutputChannels);

                    const float* const sourceChanData = outputChannelBuffer.getReadPointer (jmin (chan, outputChannelBuffer.getNumChannels() - 1));
                    AudioData::Pointer <AudioData::Float32, AudioData::NativeEndian, AudioData::NonInterleaved, AudioData::Const> s (sourceChanData);
                    d.convertSamples (s, actualBufferSize);
                }

                env->ReleaseShortArrayElements (audioBuffer, dest, 0);
                jint numWritten = env->CallIntMethod (outputDevice, AudioTrack.write, audioBuffer, 0, actualBufferSize * numDeviceOutputChannels);

                if (numWritten < actualBufferSize * numDeviceOutputChannels)
                {
                    DBG ("Audio write underrun! " << numWritten);
                }
            }
        }
    }

    int minBufferSizeOut, minBufferSizeIn;

private:
    //==============================================================================
    CriticalSection callbackLock;
    AudioIODeviceCallback* callback;
    jint sampleRate;
    int numClientInputChannels, numDeviceInputChannels, numDeviceInputChannelsAvailable;
    int numClientOutputChannels, numDeviceOutputChannels;
    int actualBufferSize;
    bool isRunning;
    String lastError;
    BigInteger activeOutputChans, activeInputChans;
    GlobalRef outputDevice, inputDevice;
    AudioSampleBuffer inputChannelBuffer, outputChannelBuffer;

    void closeDevices()
    {
        if (outputDevice != nullptr)
        {
            outputDevice.callVoidMethod (AudioTrack.stop);
            outputDevice.callVoidMethod (AudioTrack.release);
            outputDevice.clear();
        }

        if (inputDevice != nullptr)
        {
            inputDevice.callVoidMethod (AudioRecord.stop);
            inputDevice.callVoidMethod (AudioRecord.release);
            inputDevice.clear();
        }
    }

    JUCE_DECLARE_NON_COPYABLE (AndroidAudioIODevice)
};

//==============================================================================
class AndroidAudioIODeviceType  : public AudioIODeviceType
{
public:
    AndroidAudioIODeviceType()  : AudioIODeviceType (javaAudioTypeName) {}

    //==============================================================================
    void scanForDevices() {}
    StringArray getDeviceNames (bool wantInputNames) const              { return StringArray (javaAudioTypeName); }
    int getDefaultDeviceIndex (bool forInput) const                     { return 0; }
    int getIndexOfDevice (AudioIODevice* device, bool asInput) const    { return device != nullptr ? 0 : -1; }
    bool hasSeparateInputsAndOutputs() const                            { return false; }

    AudioIODevice* createDevice (const String& outputDeviceName,
                                 const String& inputDeviceName)
    {
        ScopedPointer<AndroidAudioIODevice> dev;

        if (outputDeviceName.isNotEmpty() || inputDeviceName.isNotEmpty())
        {
            dev = new AndroidAudioIODevice (outputDeviceName.isNotEmpty() ? outputDeviceName
                                                                          : inputDeviceName);

            if (dev->getCurrentSampleRate() <= 0 || dev->getDefaultBufferSize() <= 0)
                dev = nullptr;
        }

        return dev.release();
    }

private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AndroidAudioIODeviceType)
};


//==============================================================================
extern bool isOpenSLAvailable();

AudioIODeviceType* AudioIODeviceType::createAudioIODeviceType_Android()
{
   #if JUCE_USE_ANDROID_OPENSLES
    if (isOpenSLAvailable())
        return nullptr;
   #endif

    return new AndroidAudioIODeviceType();
}
