/*
 * Copyright (C) 2007 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 <stdlib.h>
#include <stdint.h>
#include <sys/types.h>

#include <cutils/properties.h>
#include <cutils/native_handle.h>

#include <utils/Errors.h>
#include <utils/Log.h>
#include <utils/StopWatch.h>

#include <ui/PixelFormat.h>
#include <ui/Surface.h>

#include "Buffer.h"
#include "clz.h"
#include "Layer.h"
#include "SurfaceFlinger.h"
#include "DisplayHardware/DisplayHardware.h"


#define DEBUG_RESIZE    0


namespace android {

// ---------------------------------------------------------------------------

const uint32_t Layer::typeInfo = LayerBaseClient::typeInfo | 4;
const char* const Layer::typeID = "Layer";

// ---------------------------------------------------------------------------

Layer::Layer(SurfaceFlinger* flinger, DisplayID display, 
        const sp<Client>& c, int32_t i)
    :   LayerBaseClient(flinger, display, c, i),
        mSecure(false),
        mNeedsBlending(true)
{
    // no OpenGL operation is possible here, since we might not be
    // in the OpenGL thread.
    mFrontBufferIndex = lcblk->getFrontBuffer();
}

Layer::~Layer()
{
    destroy();
    // the actual buffers will be destroyed here
}

// called with SurfaceFlinger::mStateLock as soon as the layer is entered
// in the purgatory list
void Layer::onRemoved()
{
    // wake up the condition
    lcblk->setStatus(NO_INIT);
}

void Layer::destroy()
{
    for (size_t i=0 ; i<NUM_BUFFERS ; i++) {
        if (mTextures[i].name != -1U) {
            glDeleteTextures(1, &mTextures[i].name);
            mTextures[i].name = -1U;
        }
        if (mTextures[i].image != EGL_NO_IMAGE_KHR) {
            EGLDisplay dpy(mFlinger->graphicPlane(0).getEGLDisplay());
            eglDestroyImageKHR(dpy, mTextures[i].image);
            mTextures[i].image = EGL_NO_IMAGE_KHR;
        }
        Mutex::Autolock _l(mLock);
        mBuffers[i].clear();
        mWidth = mHeight = 0;
    }
    mSurface.clear();
}

sp<LayerBaseClient::Surface> Layer::createSurface() const
{
    return mSurface;
}

status_t Layer::ditch()
{
    // the layer is not on screen anymore. free as much resources as possible
    destroy();
    return NO_ERROR;
}

status_t Layer::setBuffers( uint32_t w, uint32_t h,
                            PixelFormat format, uint32_t flags)
{
    PixelFormatInfo info;
    status_t err = getPixelFormatInfo(format, &info);
    if (err) return err;

    uint32_t bufferFlags = 0;
    if (flags & ISurfaceComposer::eSecure)
        bufferFlags |= Buffer::SECURE;

    mFormat = format;
    mWidth = w;
    mHeight = h;
    mSecure = (bufferFlags & Buffer::SECURE) ? true : false;
    mNeedsBlending = (info.h_alpha - info.l_alpha) > 0;
    mBufferFlags = bufferFlags;
    for (size_t i=0 ; i<NUM_BUFFERS ; i++) {
        mBuffers[i] = new Buffer();
    }
    mSurface = new SurfaceLayer(mFlinger, clientIndex(), this);
    return NO_ERROR;
}

void Layer::reloadTexture(const Region& dirty)
{
    Mutex::Autolock _l(mLock);
    sp<Buffer> buffer(getFrontBuffer());
    if (LIKELY(mFlags & DisplayHardware::DIRECT_TEXTURE)) {
        int index = mFrontBufferIndex;
        if (LIKELY(!mTextures[index].dirty)) {
            glBindTexture(GL_TEXTURE_2D, mTextures[index].name);
        } else {
            // we need to recreate the texture
            EGLDisplay dpy(mFlinger->graphicPlane(0).getEGLDisplay());
            
            // create the new texture name if needed
            if (UNLIKELY(mTextures[index].name == -1U)) {
                mTextures[index].name = createTexture();
            } else {
                glBindTexture(GL_TEXTURE_2D, mTextures[index].name);
            }

            // free the previous image
            if (mTextures[index].image != EGL_NO_IMAGE_KHR) {
                eglDestroyImageKHR(dpy, mTextures[index].image);
                mTextures[index].image = EGL_NO_IMAGE_KHR;
            }
            
            // construct an EGL_NATIVE_BUFFER_ANDROID
            android_native_buffer_t* clientBuf = buffer->getNativeBuffer();
            
            // create the new EGLImageKHR
            const EGLint attrs[] = { 
                    EGL_IMAGE_PRESERVED_KHR,    EGL_TRUE, 
                    EGL_NONE,                   EGL_NONE 
            };
            mTextures[index].image = eglCreateImageKHR(
                    dpy, EGL_NO_CONTEXT, EGL_NATIVE_BUFFER_ANDROID,
                    (EGLClientBuffer)clientBuf, attrs);

            LOGE_IF(mTextures[index].image == EGL_NO_IMAGE_KHR,
                    "eglCreateImageKHR() failed. err=0x%4x",
                    eglGetError());
            
            if (mTextures[index].image != EGL_NO_IMAGE_KHR) {
                glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, 
                        (GLeglImageOES)mTextures[index].image);
                GLint error = glGetError();
                if (UNLIKELY(error != GL_NO_ERROR)) {
                    // this failed, for instance, because we don't support
                    // NPOT.
                    // FIXME: do something!
                    mFlags &= ~DisplayHardware::DIRECT_TEXTURE;
                } else {
                    // Everything went okay!
                    mTextures[index].dirty  = false;
                    mTextures[index].width  = clientBuf->width;
                    mTextures[index].height = clientBuf->height;
                }
            }                
        }
    } else {
        GGLSurface t;
        status_t res = buffer->lock(&t, GRALLOC_USAGE_SW_READ_RARELY);
        LOGE_IF(res, "error %d (%s) locking buffer %p",
                res, strerror(res), buffer.get());
        if (res == NO_ERROR) {
            if (UNLIKELY(mTextures[0].name == -1U)) {
                mTextures[0].name = createTexture();
            }
            loadTexture(&mTextures[0], mTextures[0].name, dirty, t);
            buffer->unlock();
        }
    }
}


void Layer::onDraw(const Region& clip) const
{
    const int index = (mFlags & DisplayHardware::DIRECT_TEXTURE) ? 
            mFrontBufferIndex : 0;
    GLuint textureName = mTextures[index].name;
    if (UNLIKELY(textureName == -1LU)) {
        //LOGW("Layer %p doesn't have a texture", this);
        // the texture has not been created yet, this Layer has
        // in fact never been drawn into. this happens frequently with
        // SurfaceView.
        clearWithOpenGL(clip);
        return;
    }

    drawWithOpenGL(clip, mTextures[index]);
}

sp<SurfaceBuffer> Layer::requestBuffer(int index, int usage)
{
    sp<Buffer> buffer;

    // this ensures our client doesn't go away while we're accessing
    // the shared area.
    sp<Client> ourClient(client.promote());
    if (ourClient == 0) {
        // oops, the client is already gone
        return buffer;
    }

    /*
     * This is called from the client's Surface::dequeue(). This can happen
     * at any time, especially while we're in the middle of using the
     * buffer 'index' as our front buffer.
     * 
     * Make sure the buffer we're resizing is not the front buffer and has been
     * dequeued. Once this condition is asserted, we are guaranteed that this
     * buffer cannot become the front buffer under our feet, since we're called
     * from Surface::dequeue()
     */
    status_t err = lcblk->assertReallocate(index);
    LOGE_IF(err, "assertReallocate(%d) failed (%s)", index, strerror(-err));
    if (err != NO_ERROR) {
        // the surface may have died
        return buffer;
    }

    uint32_t w, h;
    { // scope for the lock
        Mutex::Autolock _l(mLock);
        w = mWidth;
        h = mHeight;
        buffer = mBuffers[index];
        mBuffers[index].clear();
    }


    if (buffer->getStrongCount() == 1) {
        err = buffer->reallocate(w, h, mFormat, usage, mBufferFlags);
    } else {
        // here we have to reallocate a new buffer because we could have a
        // client in our process with a reference to it (eg: status bar),
        // and we can't release the handle under its feet.
        buffer.clear();
        buffer = new Buffer(w, h, mFormat, usage, mBufferFlags);
        err = buffer->initCheck();
    }

    if (err || buffer->handle == 0) {
        LOGE_IF(err || buffer->handle == 0,
                "Layer::requestBuffer(this=%p), index=%d, w=%d, h=%d failed (%s)",
                this, index, w, h, strerror(-err));
    } else {
        LOGD_IF(DEBUG_RESIZE,
                "Layer::requestBuffer(this=%p), index=%d, w=%d, h=%d",
                this, index, w, h);
    }

    if (err == NO_ERROR && buffer->handle != 0) {
        Mutex::Autolock _l(mLock);
        if (mWidth && mHeight) {
            // and we have new buffer
            mBuffers[index] = buffer;
            // texture is now dirty...
            mTextures[index].dirty = true;
        } else {
            // oops we got killed while we were allocating the buffer
            buffer.clear();
        }
    }
    return buffer;
}

uint32_t Layer::doTransaction(uint32_t flags)
{
    const Layer::State& front(drawingState());
    const Layer::State& temp(currentState());

    // Index of the back buffer
    const bool backbufferChanged = (front.w != temp.w) || (front.h != temp.h);

    if (backbufferChanged) {
        // the size changed, we need to ask our client to request a new buffer
        LOGD_IF(DEBUG_RESIZE,
                    "resize (layer=%p), requested (%dx%d), "
                    "drawing (%d,%d), (%dx%d), (%dx%d)",
                    this, int(temp.w), int(temp.h),
                    int(drawingState().w), int(drawingState().h),
                    int(mBuffers[0]->getWidth()), int(mBuffers[0]->getHeight()),
                    int(mBuffers[1]->getWidth()), int(mBuffers[1]->getHeight()));

        // record the new size, form this point on, when the client request a
        // buffer, it'll get the new size.
        setDrawingSize(temp.w, temp.h);

        // all buffers need reallocation
        lcblk->reallocate();

        // recompute the visible region
        // FIXME: ideally we would do that only when we have received
        // a buffer of the right size
        flags |= Layer::eVisibleRegion;
        this->contentDirty = true;
        
#if 0 
        // FIXME: handle freeze lock
        // we're being resized and there is a freeze display request,
        // acquire a freeze lock, so that the screen stays put
        // until we've redrawn at the new size; this is to avoid
        // glitches upon orientation changes.
        if (mFlinger->hasFreezeRequest()) {
            // if the surface is hidden, don't try to acquire the
            // freeze lock, since hidden surfaces may never redraw
            if (!(front.flags & ISurfaceComposer::eLayerHidden)) {
                mFreezeLock = mFlinger->getFreezeLock();
            }
        }
#endif
    }

    if (temp.sequence != front.sequence) {
        if (temp.flags & ISurfaceComposer::eLayerHidden || temp.alpha == 0) {
            // this surface is now hidden, so it shouldn't hold a freeze lock
            // (it may never redraw, which is fine if it is hidden)
            mFreezeLock.clear();
        }
    }
        
    return LayerBase::doTransaction(flags);
}

void Layer::setDrawingSize(uint32_t w, uint32_t h) {
    Mutex::Autolock _l(mLock);
    mWidth = w;
    mHeight = h;
}

// ----------------------------------------------------------------------------
// pageflip handling...
// ----------------------------------------------------------------------------

void Layer::lockPageFlip(bool& recomputeVisibleRegions)
{
    ssize_t buf = lcblk->retireAndLock();
    if (buf < NO_ERROR) {
        //LOGW("nothing to retire (%s)", strerror(-buf));
        // NOTE: here the buffer is locked because we will used 
        // for composition later in the loop
        return;
    }
    
    // we retired a buffer, which becomes the new front buffer
    mFrontBufferIndex = buf;

    // get the dirty region
    sp<Buffer> newFrontBuffer(getBuffer(buf));
    const Region dirty(lcblk->getDirtyRegion(buf));
    mPostedDirtyRegion = dirty.intersect( newFrontBuffer->getBounds() );

    // FIXME: signal an event if we have more buffers waiting
    // mFlinger->signalEvent();

    reloadTexture( mPostedDirtyRegion );
}

void Layer::unlockPageFlip(
        const Transform& planeTransform, Region& outDirtyRegion)
{
    Region dirtyRegion(mPostedDirtyRegion);
    if (!dirtyRegion.isEmpty()) {
        mPostedDirtyRegion.clear();
        // The dirty region is given in the layer's coordinate space
        // transform the dirty region by the surface's transformation
        // and the global transformation.
        const Layer::State& s(drawingState());
        const Transform tr(planeTransform * s.transform);
        dirtyRegion = tr.transform(dirtyRegion);

        // At this point, the dirty region is in screen space.
        // Make sure it's constrained by the visible region (which
        // is in screen space as well).
        dirtyRegion.andSelf(visibleRegionScreen);
        outDirtyRegion.orSelf(dirtyRegion);
    }
}

void Layer::finishPageFlip()
{
    status_t err = lcblk->unlock( mFrontBufferIndex );
    LOGE_IF(err!=NO_ERROR, 
            "layer %p, buffer=%d wasn't locked!",
            this, mFrontBufferIndex);
}

// ---------------------------------------------------------------------------

Layer::SurfaceLayer::SurfaceLayer(const sp<SurfaceFlinger>& flinger,
        SurfaceID id, const sp<Layer>& owner)
    : Surface(flinger, id, owner->getIdentity(), owner)
{
}

Layer::SurfaceLayer::~SurfaceLayer()
{
}

sp<SurfaceBuffer> Layer::SurfaceLayer::requestBuffer(int index, int usage)
{
    sp<SurfaceBuffer> buffer;
    sp<Layer> owner(getOwner());
    if (owner != 0) {
        LOGE_IF(uint32_t(index)>=NUM_BUFFERS,
                "getBuffer() index (%d) out of range", index);
        if (uint32_t(index) < NUM_BUFFERS) {
            buffer = owner->requestBuffer(index, usage);
        }
    }
    return buffer;
}

// ---------------------------------------------------------------------------


}; // namespace android