/*
 * Copyright 2014,2016 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.
 */

#include <inttypes.h>

#define LOG_TAG "Camera3StreamSplitter"
#define ATRACE_TAG ATRACE_TAG_CAMERA
//#define LOG_NDEBUG 0

#include <gui/BufferItem.h>
#include <gui/IGraphicBufferConsumer.h>
#include <gui/IGraphicBufferProducer.h>
#include <gui/BufferQueue.h>
#include <gui/Surface.h>

#include <ui/GraphicBuffer.h>

#include <binder/ProcessState.h>

#include <utils/Trace.h>

#include <cutils/atomic.h>

#include "Camera3StreamSplitter.h"

namespace android {

status_t Camera3StreamSplitter::connect(const std::vector<sp<Surface> >& surfaces,
        uint32_t consumerUsage, size_t halMaxBuffers, sp<Surface>* consumer) {
    ATRACE_CALL();
    if (consumer == nullptr) {
        SP_LOGE("%s: consumer pointer is NULL", __FUNCTION__);
        return BAD_VALUE;
    }

    Mutex::Autolock lock(mMutex);
    status_t res = OK;

    if (mOutputs.size() > 0 || mConsumer != nullptr) {
        SP_LOGE("%s: already connected", __FUNCTION__);
        return BAD_VALUE;
    }
    if (mBuffers.size() > 0) {
        SP_LOGE("%s: still has %zu pending buffers", __FUNCTION__, mBuffers.size());
        return BAD_VALUE;
    }

    mMaxHalBuffers = halMaxBuffers;
    mConsumerName = getUniqueConsumerName();
    // Add output surfaces. This has to be before creating internal buffer queue
    // in order to get max consumer side buffers.
    for (size_t i = 0; i < surfaces.size(); i++) {
        if (surfaces[i] == nullptr) {
            SP_LOGE("%s: Fatal: surface is NULL", __FUNCTION__);
            return BAD_VALUE;
        }
        res = addOutputLocked(surfaces[i]);
        if (res != OK) {
            SP_LOGE("%s: Failed to add output surface: %s(%d)",
                    __FUNCTION__, strerror(-res), res);
            return res;
        }
    }

    // Create BufferQueue for input
    BufferQueue::createBufferQueue(&mProducer, &mConsumer);

    // Allocate 1 extra buffer to handle the case where all buffers are detached
    // from input, and attached to the outputs. In this case, the input queue's
    // dequeueBuffer can still allocate 1 extra buffer before being blocked by
    // the output's attachBuffer().
    mBufferItemConsumer = new BufferItemConsumer(mConsumer, consumerUsage,
                                                 mMaxConsumerBuffers+1);
    if (mBufferItemConsumer == nullptr) {
        return NO_MEMORY;
    }
    mConsumer->setConsumerName(mConsumerName);

    *consumer = new Surface(mProducer);
    if (*consumer == nullptr) {
        return NO_MEMORY;
    }

    res = mConsumer->consumerConnect(this, /* controlledByApp */ false);

    SP_LOGV("%s: connected", __FUNCTION__);
    return res;
}

status_t Camera3StreamSplitter::getOnFrameAvailableResult() {
    ATRACE_CALL();
    return mOnFrameAvailableRes.load();
}

void Camera3StreamSplitter::disconnect() {
    ATRACE_CALL();
    Mutex::Autolock lock(mMutex);

    for (auto& notifier : mNotifiers) {
        sp<IGraphicBufferProducer> producer = notifier.first;
        sp<OutputListener> listener = notifier.second;
        IInterface::asBinder(producer)->unlinkToDeath(listener);
    }
    mNotifiers.clear();

    for (auto& output : mOutputs) {
        output->disconnect(NATIVE_WINDOW_API_CAMERA);
    }
    mOutputs.clear();
    mOutputSlots.clear();

    mConsumer->consumerDisconnect();

    if (mBuffers.size() > 0) {
        SP_LOGW("%zu buffers still being tracked", mBuffers.size());
        mBuffers.clear();
    }

    mMaxHalBuffers = 0;
    mMaxConsumerBuffers = 0;
    SP_LOGV("%s: Disconnected", __FUNCTION__);
}


Camera3StreamSplitter::~Camera3StreamSplitter() {
    disconnect();
}

status_t Camera3StreamSplitter::addOutput(const sp<Surface>& outputQueue) {
    ATRACE_CALL();
    Mutex::Autolock lock(mMutex);
    status_t res = addOutputLocked(outputQueue);

    if (res != OK) {
        SP_LOGE("%s: addOutputLocked failed %d", __FUNCTION__, res);
        return res;
    }

    res = mConsumer->setMaxAcquiredBufferCount(mMaxConsumerBuffers+1);

    return res;
}

status_t Camera3StreamSplitter::addOutputLocked(const sp<Surface>& outputQueue) {
    ATRACE_CALL();
    if (outputQueue == nullptr) {
        SP_LOGE("addOutput: outputQueue must not be NULL");
        return BAD_VALUE;
    }

    sp<IGraphicBufferProducer> gbp = outputQueue->getIGraphicBufferProducer();
    // Connect to the buffer producer
    sp<OutputListener> listener(new OutputListener(this, gbp));
    IInterface::asBinder(gbp)->linkToDeath(listener);
    status_t res = outputQueue->connect(NATIVE_WINDOW_API_CAMERA, listener);
    if (res != NO_ERROR) {
        SP_LOGE("addOutput: failed to connect (%d)", res);
        return res;
    }

    // Query consumer side buffer count, and update overall buffer count
    int maxConsumerBuffers = 0;
    res = static_cast<ANativeWindow*>(outputQueue.get())->query(
            outputQueue.get(),
            NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, &maxConsumerBuffers);
    if (res != OK) {
        SP_LOGE("%s: Unable to query consumer undequeued buffer count"
              " for surface", __FUNCTION__);
        return res;
    }

    SP_LOGV("%s: Consumer wants %d buffers, Producer wants %zu", __FUNCTION__,
            maxConsumerBuffers, mMaxHalBuffers);
    size_t totalBufferCount = maxConsumerBuffers + mMaxHalBuffers;
    res = native_window_set_buffer_count(outputQueue.get(),
            totalBufferCount);
    if (res != OK) {
        SP_LOGE("%s: Unable to set buffer count for surface %p",
                __FUNCTION__, outputQueue.get());
        return res;
    }

    // Set dequeueBuffer/attachBuffer timeout if the consumer is not hw composer or hw texture.
    // We need skip these cases as timeout will disable the non-blocking (async) mode.
    int32_t usage = 0;
    static_cast<ANativeWindow*>(outputQueue.get())->query(
            outputQueue.get(),
            NATIVE_WINDOW_CONSUMER_USAGE_BITS, &usage);
    if (!(usage & (GRALLOC_USAGE_HW_COMPOSER | GRALLOC_USAGE_HW_TEXTURE))) {
        outputQueue->setDequeueTimeout(kDequeueBufferTimeout);
    }

    res = gbp->allowAllocation(false);
    if (res != OK) {
        SP_LOGE("%s: Failed to turn off allocation for outputQueue", __FUNCTION__);
        return res;
    }

    // Add new entry into mOutputs
    mOutputs.push_back(gbp);
    mNotifiers[gbp] = listener;
    mOutputSlots[gbp] = std::make_unique<OutputSlots>(totalBufferCount);

    mMaxConsumerBuffers += maxConsumerBuffers;
    return NO_ERROR;
}

status_t Camera3StreamSplitter::outputBufferLocked(const sp<IGraphicBufferProducer>& output,
        const BufferItem& bufferItem) {
    ATRACE_CALL();
    status_t res;
    IGraphicBufferProducer::QueueBufferInput queueInput(
            bufferItem.mTimestamp, bufferItem.mIsAutoTimestamp,
            bufferItem.mDataSpace, bufferItem.mCrop,
            static_cast<int32_t>(bufferItem.mScalingMode),
            bufferItem.mTransform, bufferItem.mFence);

    IGraphicBufferProducer::QueueBufferOutput queueOutput;

    uint64_t bufferId = bufferItem.mGraphicBuffer->getId();
    const BufferTracker& tracker = *(mBuffers[bufferId]);
    int slot = getSlotForOutputLocked(output, tracker.getBuffer());

    // In case the output BufferQueue has its own lock, if we hold splitter lock while calling
    // queueBuffer (which will try to acquire the output lock), the output could be holding its
    // own lock calling releaseBuffer (which  will try to acquire the splitter lock), running into
    // circular lock situation.
    mMutex.unlock();
    res = output->queueBuffer(slot, queueInput, &queueOutput);
    mMutex.lock();

    SP_LOGV("%s: Queuing buffer to buffer queue %p slot %d returns %d",
            __FUNCTION__, output.get(), slot, res);
    if (res != OK) {
        if (res != NO_INIT && res != DEAD_OBJECT) {
            SP_LOGE("Queuing buffer to output failed (%d)", res);
        }
        // If we just discovered that this output has been abandoned, note
        // that, increment the release count so that we still release this
        // buffer eventually, and move on to the next output
        onAbandonedLocked();
        decrementBufRefCountLocked(bufferItem.mGraphicBuffer->getId(), output);
        return res;
    }

    // If the queued buffer replaces a pending buffer in the async
    // queue, no onBufferReleased is called by the buffer queue.
    // Proactively trigger the callback to avoid buffer loss.
    if (queueOutput.bufferReplaced) {
        onBufferReleasedByOutputLocked(output);
    }

    return res;
}

String8 Camera3StreamSplitter::getUniqueConsumerName() {
    static volatile int32_t counter = 0;
    return String8::format("Camera3StreamSplitter-%d", android_atomic_inc(&counter));
}

status_t Camera3StreamSplitter::notifyBufferReleased(const sp<GraphicBuffer>& buffer) {
    ATRACE_CALL();
    status_t res = OK;

    Mutex::Autolock lock(mMutex);

    uint64_t bufferId = buffer->getId();
    std::unique_ptr<BufferTracker> tracker_ptr = std::move(mBuffers[bufferId]);
    mBuffers.erase(bufferId);

    for (const auto surface : tracker_ptr->requestedSurfaces()) {
        sp<IGraphicBufferProducer>& gbp = mOutputs[surface];
        OutputSlots& outputSlots = *(mOutputSlots[gbp]);
        int slot = getSlotForOutputLocked(gbp, buffer);
        if (slot != BufferItem::INVALID_BUFFER_SLOT) {
             gbp->detachBuffer(slot);
             outputSlots[slot].clear();
        }
    }

    return res;
}

status_t Camera3StreamSplitter::attachBufferToOutputs(ANativeWindowBuffer* anb,
        const std::vector<size_t>& surface_ids) {
    ATRACE_CALL();
    status_t res = OK;

    Mutex::Autolock lock(mMutex);

    sp<GraphicBuffer> gb(static_cast<GraphicBuffer*>(anb));
    uint64_t bufferId = gb->getId();

    // Initialize buffer tracker for this input buffer
    auto tracker = std::make_unique<BufferTracker>(gb, surface_ids);

    for (auto& surface_id : surface_ids) {
        sp<IGraphicBufferProducer>& gbp = mOutputs[surface_id];
        int slot = BufferItem::INVALID_BUFFER_SLOT;
        //Temporarly Unlock the mutex when trying to attachBuffer to the output
        //queue, because attachBuffer could block in case of a slow consumer. If
        //we block while holding the lock, onFrameAvailable and onBufferReleased
        //will block as well because they need to acquire the same lock.
        mMutex.unlock();
        res = gbp->attachBuffer(&slot, gb);
        mMutex.lock();
        if (res != OK) {
            SP_LOGE("%s: Cannot acquireBuffer from GraphicBufferProducer %p: %s (%d)",
                    __FUNCTION__, gbp.get(), strerror(-res), res);
            return res;
        }
        auto& outputSlots = *mOutputSlots[gbp];
        if (outputSlots[slot] != nullptr) {
            // If the buffer is attached to a slot which already contains a buffer,
            // the previous buffer will be removed from the output queue. Decrement
            // the reference count accordingly.
            decrementBufRefCountLocked(outputSlots[slot]->getId(), gbp);
        }
        SP_LOGV("%s: Attached buffer %p to slot %d on output %p.",__FUNCTION__, gb.get(),
                slot, gbp.get());
        outputSlots[slot] = gb;
    }

    mBuffers[bufferId] = std::move(tracker);

    return res;
}

void Camera3StreamSplitter::onFrameAvailable(const BufferItem& /*item*/) {
    ATRACE_CALL();
    Mutex::Autolock lock(mMutex);

    // Acquire and detach the buffer from the input
    BufferItem bufferItem;
    status_t res = mConsumer->acquireBuffer(&bufferItem, /* presentWhen */ 0);
    if (res != NO_ERROR) {
        SP_LOGE("%s: Acquiring buffer from input failed (%d)", __FUNCTION__, res);
        mOnFrameAvailableRes.store(res);
        return;
    }
    if (mBuffers.find(bufferItem.mGraphicBuffer->getId()) == mBuffers.end()) {
        SP_LOGE("%s: Acquired buffer doesn't exist in attached buffer map",
                __FUNCTION__);
        mOnFrameAvailableRes.store(INVALID_OPERATION);
        return;
    }

    SP_LOGV("acquired buffer %" PRId64 " from input at slot %d",
            bufferItem.mGraphicBuffer->getId(), bufferItem.mSlot);

    res = mConsumer->detachBuffer(bufferItem.mSlot);
    if (res != NO_ERROR) {
        SP_LOGE("%s: detaching buffer from input failed (%d)", __FUNCTION__, res);
        mOnFrameAvailableRes.store(res);
        return;
    }

    // Attach and queue the buffer to each of the outputs
    BufferTracker& tracker = *(mBuffers[bufferItem.mGraphicBuffer->getId()]);

    SP_LOGV("%s: BufferTracker for buffer %" PRId64 ", number of requests %zu",
           __FUNCTION__, bufferItem.mGraphicBuffer->getId(), tracker.requestedSurfaces().size());
    for (const auto id : tracker.requestedSurfaces()) {

        LOG_ALWAYS_FATAL_IF(id >= mOutputs.size(),
                "requested surface id exceeding max registered ids");

        res = outputBufferLocked(mOutputs[id], bufferItem);
        if (res != OK) {
            SP_LOGE("%s: outputBufferLocked failed %d", __FUNCTION__, res);
            mOnFrameAvailableRes.store(res);
            // If we fail to send buffer to certain output, keep sending to
            // other outputs.
            continue;
        }
    }

    mOnFrameAvailableRes.store(res);
}

void Camera3StreamSplitter::decrementBufRefCountLocked(uint64_t id,
        const sp<IGraphicBufferProducer>& from) {
    ATRACE_CALL();
    size_t referenceCount = mBuffers[id]->decrementReferenceCountLocked();

    removeSlotForOutputLocked(from, mBuffers[id]->getBuffer());
    if (referenceCount > 0) {
        return;
    }

    // We no longer need to track the buffer now that it is being returned to the
    // input. Note that this should happen before we unlock the mutex and call
    // releaseBuffer, to avoid the case where the same bufferId is acquired in
    // attachBufferToOutputs resulting in a new BufferTracker with same bufferId
    // overwrites the current one.
    std::unique_ptr<BufferTracker> tracker_ptr = std::move(mBuffers[id]);
    mBuffers.erase(id);

    // Attach and release the buffer back to the input
    int consumerSlot = BufferItem::INVALID_BUFFER_SLOT;
    status_t res = mConsumer->attachBuffer(&consumerSlot, tracker_ptr->getBuffer());
    if (res != NO_ERROR) {
        SP_LOGE("%s: attaching buffer to input failed (%d)", __FUNCTION__, res);
        return;
    }

    // Temporarily unlock mutex to avoid circular lock:
    // 1. This function holds splitter lock, calls releaseBuffer which triggers
    // onBufferReleased in Camera3OutputStream. onBufferReleased waits on the
    // OutputStream lock
    // 2. Camera3SharedOutputStream::getBufferLocked calls
    // attachBufferToOutputs, which holds the stream lock, and waits for the
    // splitter lock.
    sp<IGraphicBufferConsumer> consumer(mConsumer);
    mMutex.unlock();
    if (consumer != nullptr) {
        res = consumer->releaseBuffer(consumerSlot, /* frameNumber */ 0,
                EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, tracker_ptr->getMergedFence());
    } else {
        SP_LOGE("%s: consumer has become null!", __FUNCTION__);
    }
    mMutex.lock();
    // If the producer of this queue is disconnected, -22 error will occur
    if (res != NO_ERROR) {
        SP_LOGE("%s: releaseBuffer returns %d", __FUNCTION__, res);
    }
}

void Camera3StreamSplitter::onBufferReleasedByOutput(
        const sp<IGraphicBufferProducer>& from) {
    ATRACE_CALL();
    Mutex::Autolock lock(mMutex);

    onBufferReleasedByOutputLocked(from);
}

void Camera3StreamSplitter::onBufferReleasedByOutputLocked(
        const sp<IGraphicBufferProducer>& from) {
    ATRACE_CALL();
    sp<GraphicBuffer> buffer;
    sp<Fence> fence;
    status_t res = from->detachNextBuffer(&buffer, &fence);
    if (res == NO_INIT) {
        // If we just discovered that this output has been abandoned, note that,
        // but we can't do anything else, since buffer is invalid
        onAbandonedLocked();
        return;
    } else if (res == NO_MEMORY) {
        SP_LOGV("%s: No free buffers", __FUNCTION__);
        return;
    } else if (res != OK) {
        SP_LOGE("%s: detaching buffer from output failed (%d)", __FUNCTION__, res);
        return;
    }

    BufferTracker& tracker = *(mBuffers[buffer->getId()]);
    // Merge the release fence of the incoming buffer so that the fence we send
    // back to the input includes all of the outputs' fences
    if (fence != nullptr && fence->isValid()) {
        tracker.mergeFence(fence);
    }
    SP_LOGV("detached buffer %" PRId64 " %p from output %p",
            buffer->getId(), buffer.get(), from.get());

    // Check to see if this is the last outstanding reference to this buffer
    decrementBufRefCountLocked(buffer->getId(), from);
}

void Camera3StreamSplitter::onAbandonedLocked() {
    // If this is called from binderDied callback, it means the app process
    // holding the binder has died. CameraService will be notified of the binder
    // death, and camera device will be closed, which in turn calls
    // disconnect().
    //
    // If this is called from onBufferReleasedByOutput or onFrameAvailable, one
    // consumer being abanoned shouldn't impact the other consumer. So we won't
    // stop the buffer flow.
    //
    // In both cases, we don't need to do anything here.
    SP_LOGV("One of my outputs has abandoned me");
}

int Camera3StreamSplitter::getSlotForOutputLocked(const sp<IGraphicBufferProducer>& gbp,
        const sp<GraphicBuffer>& gb) {
    auto& outputSlots = *mOutputSlots[gbp];

    for (size_t i = 0; i < outputSlots.size(); i++) {
        if (outputSlots[i] == gb) {
            return (int)i;
        }
    }

    SP_LOGE("%s: Cannot find slot for gb %p on output %p", __FUNCTION__, gb.get(),
            gbp.get());
    return BufferItem::INVALID_BUFFER_SLOT;
}

status_t Camera3StreamSplitter::removeSlotForOutputLocked(const sp<IGraphicBufferProducer>& gbp,
        const sp<GraphicBuffer>& gb) {
    auto& outputSlots = *mOutputSlots[gbp];

    for (size_t i = 0; i < outputSlots.size(); i++) {
        if (outputSlots[i] == gb) {
           outputSlots[i].clear();
           return NO_ERROR;
        }
    }

    SP_LOGE("%s: Cannot find slot for gb %p on output %p", __FUNCTION__, gb.get(),
            gbp.get());
    return BAD_VALUE;
}

Camera3StreamSplitter::OutputListener::OutputListener(
        wp<Camera3StreamSplitter> splitter,
        wp<IGraphicBufferProducer> output)
      : mSplitter(splitter), mOutput(output) {}

void Camera3StreamSplitter::OutputListener::onBufferReleased() {
    ATRACE_CALL();
    sp<Camera3StreamSplitter> splitter = mSplitter.promote();
    sp<IGraphicBufferProducer> output = mOutput.promote();
    if (splitter != nullptr && output != nullptr) {
        splitter->onBufferReleasedByOutput(output);
    }
}

void Camera3StreamSplitter::OutputListener::binderDied(const wp<IBinder>& /* who */) {
    sp<Camera3StreamSplitter> splitter = mSplitter.promote();
    if (splitter != nullptr) {
        Mutex::Autolock lock(splitter->mMutex);
        splitter->onAbandonedLocked();
    }
}

Camera3StreamSplitter::BufferTracker::BufferTracker(
        const sp<GraphicBuffer>& buffer, const std::vector<size_t>& requestedSurfaces)
      : mBuffer(buffer), mMergedFence(Fence::NO_FENCE), mRequestedSurfaces(requestedSurfaces),
        mReferenceCount(requestedSurfaces.size()) {}

void Camera3StreamSplitter::BufferTracker::mergeFence(const sp<Fence>& with) {
    mMergedFence = Fence::merge(String8("Camera3StreamSplitter"), mMergedFence, with);
}

size_t Camera3StreamSplitter::BufferTracker::decrementReferenceCountLocked() {
    if (mReferenceCount > 0)
        --mReferenceCount;
    return mReferenceCount;
}

} // namespace android
