/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "AAudioServiceStreamMMAP"
//#define LOG_NDEBUG 0
#include <utils/Log.h>

#include <atomic>
#include <stdint.h>

#include <utils/String16.h>
#include <media/nbaio/AudioStreamOutSink.h>
#include <media/MmapStreamInterface.h>

#include "AAudioServiceStreamBase.h"
#include "AAudioServiceStreamMMAP.h"
#include "binding/AudioEndpointParcelable.h"
#include "SharedMemoryProxy.h"
#include "utility/AAudioUtilities.h"

using android::base::unique_fd;
using namespace android;
using namespace aaudio;

#define AAUDIO_BUFFER_CAPACITY_MIN    4 * 512
#define AAUDIO_SAMPLE_RATE_DEFAULT    48000

// This is an estimate of the time difference between the HW and the MMAP time.
// TODO Get presentation timestamps from the HAL instead of using these estimates.
#define OUTPUT_ESTIMATED_HARDWARE_OFFSET_NANOS  (3 * AAUDIO_NANOS_PER_MILLISECOND)
#define INPUT_ESTIMATED_HARDWARE_OFFSET_NANOS   (-1 * AAUDIO_NANOS_PER_MILLISECOND)

/**
 * Service Stream that uses an MMAP buffer.
 */

AAudioServiceStreamMMAP::AAudioServiceStreamMMAP(const android::AudioClient& serviceClient,
                                                 bool inService)
        : AAudioServiceStreamBase()
        , mMmapStreamCallback(new MyMmapStreamCallback(*this))
        , mPreviousFrameCounter(0)
        , mMmapStream(nullptr)
        , mServiceClient(serviceClient)
        , mInService(inService) {
}

aaudio_result_t AAudioServiceStreamMMAP::close() {
    if (mState == AAUDIO_STREAM_STATE_CLOSED) {
        return AAUDIO_OK;
    }
    stop();
    if (mMmapStream != 0) {
        mMmapStream.clear(); // TODO review. Is that all we have to do?
        // Apparently the above close is asynchronous. An attempt to open a new device
        // right after a close can fail. Also some callbacks may still be in flight!
        // FIXME Make closing synchronous.
        AudioClock::sleepForNanos(100 * AAUDIO_NANOS_PER_MILLISECOND);
    }

    return AAudioServiceStreamBase::close();
}

// Open stream on HAL and pass information about the shared memory buffer back to the client.
aaudio_result_t AAudioServiceStreamMMAP::open(const aaudio::AAudioStreamRequest &request,
                                       aaudio::AAudioStreamConfiguration &configurationOutput) {
    const audio_attributes_t attributes = {
        .content_type = AUDIO_CONTENT_TYPE_MUSIC,
        .usage = AUDIO_USAGE_MEDIA,
        .source = AUDIO_SOURCE_VOICE_RECOGNITION,
        .flags = AUDIO_FLAG_LOW_LATENCY,
        .tags = ""
    };
    audio_config_base_t config;

    aaudio_result_t result = AAudioServiceStreamBase::open(request, configurationOutput);
    if (result != AAUDIO_OK) {
        ALOGE("AAudioServiceStreamBase open returned %d", result);
        return result;
    }

    const AAudioStreamConfiguration &configurationInput = request.getConstantConfiguration();
    audio_port_handle_t deviceId = configurationInput.getDeviceId();
    aaudio_direction_t direction = request.getDirection();

    // Fill in config
    aaudio_format_t aaudioFormat = configurationInput.getFormat();
    if (aaudioFormat == AAUDIO_UNSPECIFIED || aaudioFormat == AAUDIO_FORMAT_PCM_FLOAT) {
        aaudioFormat = AAUDIO_FORMAT_PCM_I16;
    }
    config.format = AAudioConvert_aaudioToAndroidDataFormat(aaudioFormat);

    int32_t aaudioSampleRate = configurationInput.getSampleRate();
    if (aaudioSampleRate == AAUDIO_UNSPECIFIED) {
        aaudioSampleRate = AAUDIO_SAMPLE_RATE_DEFAULT;
    }
    config.sample_rate = aaudioSampleRate;

    int32_t aaudioSamplesPerFrame = configurationInput.getSamplesPerFrame();

    if (direction == AAUDIO_DIRECTION_OUTPUT) {
        config.channel_mask = (aaudioSamplesPerFrame == AAUDIO_UNSPECIFIED)
                            ? AUDIO_CHANNEL_OUT_STEREO
                            : audio_channel_out_mask_from_count(aaudioSamplesPerFrame);
        mHardwareTimeOffsetNanos = OUTPUT_ESTIMATED_HARDWARE_OFFSET_NANOS; // frames at DAC later

    } else if (direction == AAUDIO_DIRECTION_INPUT) {
        config.channel_mask =  (aaudioSamplesPerFrame == AAUDIO_UNSPECIFIED)
                            ? AUDIO_CHANNEL_IN_STEREO
                            : audio_channel_in_mask_from_count(aaudioSamplesPerFrame);
        mHardwareTimeOffsetNanos = INPUT_ESTIMATED_HARDWARE_OFFSET_NANOS; // frames at ADC earlier

    } else {
        ALOGE("openMmapStream - invalid direction = %d", direction);
        return AAUDIO_ERROR_ILLEGAL_ARGUMENT;
    }

    MmapStreamInterface::stream_direction_t streamDirection = (direction == AAUDIO_DIRECTION_OUTPUT)
        ? MmapStreamInterface::DIRECTION_OUTPUT : MmapStreamInterface::DIRECTION_INPUT;

    // Open HAL stream.
    status_t status = MmapStreamInterface::openMmapStream(streamDirection,
                                                          &attributes,
                                                          &config,
                                                          mMmapClient,
                                                          &deviceId,
                                                          mMmapStreamCallback,
                                                          mMmapStream,
                                                          &mPortHandle);
    if (status != OK) {
        ALOGE("openMmapStream returned status %d", status);
        return AAUDIO_ERROR_UNAVAILABLE;
    }

    if (deviceId == AAUDIO_UNSPECIFIED) {
        ALOGW("AAudioServiceStreamMMAP::open() - openMmapStream() failed to set deviceId");
    }

    // Create MMAP/NOIRQ buffer.
    int32_t minSizeFrames = configurationInput.getBufferCapacity();
    if (minSizeFrames <= 0) { // zero will get rejected
        minSizeFrames = AAUDIO_BUFFER_CAPACITY_MIN;
    }
    status = mMmapStream->createMmapBuffer(minSizeFrames, &mMmapBufferinfo);
    if (status != OK) {
        ALOGE("AAudioServiceStreamMMAP::open() - createMmapBuffer() returned status %d",
              status);
        return AAUDIO_ERROR_UNAVAILABLE;
    } else {
        ALOGD("createMmapBuffer status = %d, buffer_size = %d, burst_size %d"
                ", Sharable FD: %s",
              status,
              abs(mMmapBufferinfo.buffer_size_frames),
              mMmapBufferinfo.burst_size_frames,
              mMmapBufferinfo.buffer_size_frames < 0 ? "Yes" : "No");
    }

    mCapacityInFrames = mMmapBufferinfo.buffer_size_frames;
    // FIXME: the audio HAL indicates if the shared memory fd can be shared outside of audioserver
    // by returning a negative buffer size
    if (mCapacityInFrames < 0) {
        // Exclusive mode is possible from any client
        mCapacityInFrames = -mCapacityInFrames;
    } else {
        // exclusive mode is only possible if the final fd destination is inside audioserver
        if ((mMmapClient.clientUid != mServiceClient.clientUid) &&
                configurationInput.getSharingMode() == AAUDIO_SHARING_MODE_EXCLUSIVE) {
            // Fallback is handled by caller but indicate what is possible in case
            // this is used in the future
            configurationOutput.setSharingMode(AAUDIO_SHARING_MODE_SHARED);
            return AAUDIO_ERROR_UNAVAILABLE;
        }
    }

    // Get information about the stream and pass it back to the caller.
    mSamplesPerFrame = (direction == AAUDIO_DIRECTION_OUTPUT)
                           ? audio_channel_count_from_out_mask(config.channel_mask)
                           : audio_channel_count_from_in_mask(config.channel_mask);

    // AAudio creates a copy of this FD and retains ownership of the copy.
    // Assume that AudioFlinger will close the original shared_memory_fd.
    mAudioDataFileDescriptor.reset(dup(mMmapBufferinfo.shared_memory_fd));
    if (mAudioDataFileDescriptor.get() == -1) {
        ALOGE("AAudioServiceStreamMMAP::open() - could not dup shared_memory_fd");
        return AAUDIO_ERROR_INTERNAL; // TODO review
    }
    mFramesPerBurst = mMmapBufferinfo.burst_size_frames;
    mAudioFormat = AAudioConvert_androidToAAudioDataFormat(config.format);
    mSampleRate = config.sample_rate;

    // Scale up the burst size to meet the minimum equivalent in microseconds.
    // This is to avoid waking the CPU too often when the HW burst is very small
    // or at high sample rates.
    int32_t burstMinMicros = AAudioProperty_getHardwareBurstMinMicros();
    int32_t burstMicros = 0;
    do {
        if (burstMicros > 0) {  // skip first loop
            mFramesPerBurst *= 2;
        }
        burstMicros = mFramesPerBurst * static_cast<int64_t>(1000000) / mSampleRate;
    } while (burstMicros < burstMinMicros);

    ALOGD("AAudioServiceStreamMMAP::open() original burst = %d, minMicros = %d, final burst = %d\n",
          mMmapBufferinfo.burst_size_frames, burstMinMicros, mFramesPerBurst);

    ALOGD("AAudioServiceStreamMMAP::open() actual rate = %d, channels = %d, deviceId = %d\n",
          mSampleRate, mSamplesPerFrame, deviceId);

    // Fill in AAudioStreamConfiguration
    configurationOutput.setSampleRate(mSampleRate);
    configurationOutput.setSamplesPerFrame(mSamplesPerFrame);
    configurationOutput.setFormat(mAudioFormat);
    configurationOutput.setDeviceId(deviceId);

    setState(AAUDIO_STREAM_STATE_OPEN);
    return AAUDIO_OK;
}

/**
 * Start the flow of data.
 */
aaudio_result_t AAudioServiceStreamMMAP::start() {
    if (isRunning()) {
        return AAUDIO_OK;
    }
    if (mMmapStream == nullptr) return AAUDIO_ERROR_NULL;
    aaudio_result_t result;
    status_t status = mMmapStream->start(mServiceClient, &mPortHandle);
    if (status != OK) {
        ALOGE("AAudioServiceStreamMMAP::start() mMmapStream->start() returned %d", status);
        disconnect();
        result = AAudioConvert_androidToAAudioResult(status);
    } else {
        result = AAudioServiceStreamBase::start();
        if (!mInService && result == AAUDIO_OK) {
            startClient(mMmapClient, &mClientHandle);
        }
    }
    return result;
}

/**
 * Stop the flow of data such that start() can resume with loss of data.
 */
aaudio_result_t AAudioServiceStreamMMAP::pause() {
    if (!isRunning()) {
        return AAUDIO_OK;
    }
    if (mMmapStream == nullptr) return AAUDIO_ERROR_NULL;
    aaudio_result_t result1 = AAudioServiceStreamBase::pause();
    if (!mInService) {
        stopClient(mClientHandle);
    }
    status_t status = mMmapStream->stop(mPortHandle);
    mFramesRead.reset32();
    return (result1 != AAUDIO_OK) ? result1 : AAudioConvert_androidToAAudioResult(status);
}

aaudio_result_t AAudioServiceStreamMMAP::stop() {
    if (!isRunning()) {
        return AAUDIO_OK;
    }
    if (mMmapStream == nullptr) return AAUDIO_ERROR_NULL;
    aaudio_result_t result1 = AAudioServiceStreamBase::stop();
    if (!mInService) {
        stopClient(mClientHandle);
    }
    aaudio_result_t status = mMmapStream->stop(mPortHandle);
    mFramesRead.reset32();
    return (result1 != AAUDIO_OK) ? result1 :  AAudioConvert_androidToAAudioResult(status);
}

/**
 *  Discard any data held by the underlying HAL or Service.
 */
aaudio_result_t AAudioServiceStreamMMAP::flush() {
    if (mMmapStream == nullptr) return AAUDIO_ERROR_NULL;
    // TODO how do we flush an MMAP/NOIRQ buffer? sync pointers?
    return AAudioServiceStreamBase::flush();;
}

aaudio_result_t AAudioServiceStreamMMAP::startClient(const android::AudioClient& client,
                                                     audio_port_handle_t *clientHandle) {
    return AAudioConvert_androidToAAudioResult(mMmapStream->start(client, clientHandle));
}

aaudio_result_t AAudioServiceStreamMMAP::stopClient(audio_port_handle_t clientHandle) {
    return AAudioConvert_androidToAAudioResult(mMmapStream->stop(clientHandle));
}

// Get free-running DSP or DMA hardware position from the HAL.
aaudio_result_t AAudioServiceStreamMMAP::getFreeRunningPosition(int64_t *positionFrames,
                                                                int64_t *timeNanos) {
    struct audio_mmap_position position;
    if (mMmapStream == nullptr) {
        disconnect();
        return AAUDIO_ERROR_NULL;
    }
    status_t status = mMmapStream->getMmapPosition(&position);
    aaudio_result_t result = AAudioConvert_androidToAAudioResult(status);
    if (result == AAUDIO_ERROR_UNAVAILABLE) {
        ALOGW("sendCurrentTimestamp(): getMmapPosition() has no position data yet");
    } else if (result != AAUDIO_OK) {
        ALOGE("sendCurrentTimestamp(): getMmapPosition() returned status %d", status);
        disconnect();
    } else {
        mFramesRead.update32(position.position_frames);

        Timestamp timestamp(mFramesRead.get(), position.time_nanoseconds);
        mAtomicTimestamp.write(timestamp);
        *positionFrames = timestamp.getPosition();
        *timeNanos = timestamp.getNanoseconds();
    }
    return result;
}

// Get timestamp that was written by getFreeRunningPosition()
aaudio_result_t AAudioServiceStreamMMAP::getHardwareTimestamp(int64_t *positionFrames,
                                                                int64_t *timeNanos) {
    // TODO Get presentation timestamp from the HAL
    if (mAtomicTimestamp.isValid()) {
        Timestamp timestamp = mAtomicTimestamp.read();
        *positionFrames = timestamp.getPosition();
        *timeNanos = timestamp.getNanoseconds() + mHardwareTimeOffsetNanos;
        return AAUDIO_OK;
    } else {
        return AAUDIO_ERROR_UNAVAILABLE;
    }
}

void AAudioServiceStreamMMAP::onTearDown() {
    ALOGD("AAudioServiceStreamMMAP::onTearDown() called");
    disconnect();
};

void AAudioServiceStreamMMAP::onVolumeChanged(audio_channel_mask_t channels,
                     android::Vector<float> values) {
    // TODO do we really need a different volume for each channel?
    float volume = values[0];
    ALOGD("AAudioServiceStreamMMAP::onVolumeChanged() volume[0] = %f", volume);
    sendServiceEvent(AAUDIO_SERVICE_EVENT_VOLUME, volume);
};

void AAudioServiceStreamMMAP::onRoutingChanged(audio_port_handle_t deviceId) {
    ALOGD("AAudioServiceStreamMMAP::onRoutingChanged() called with %d, old = %d",
          deviceId, mDeviceId);
    if (mDeviceId != AUDIO_PORT_HANDLE_NONE  && mDeviceId != deviceId) {
        disconnect();
    }
    mDeviceId = deviceId;
};

/**
 * Get an immutable description of the data queue from the HAL.
 */
aaudio_result_t AAudioServiceStreamMMAP::getDownDataDescription(AudioEndpointParcelable &parcelable)
{
    // Gather information on the data queue based on HAL info.
    int32_t bytesPerFrame = calculateBytesPerFrame();
    int32_t capacityInBytes = mCapacityInFrames * bytesPerFrame;
    int fdIndex = parcelable.addFileDescriptor(mAudioDataFileDescriptor, capacityInBytes);
    parcelable.mDownDataQueueParcelable.setupMemory(fdIndex, 0, capacityInBytes);
    parcelable.mDownDataQueueParcelable.setBytesPerFrame(bytesPerFrame);
    parcelable.mDownDataQueueParcelable.setFramesPerBurst(mFramesPerBurst);
    parcelable.mDownDataQueueParcelable.setCapacityInFrames(mCapacityInFrames);
    return AAUDIO_OK;
}