/*
 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
 *
 * 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 <android/log.h>
#include <string.h>

#include "libdisplay/GonkDisplay.h"
#include "Framebuffer.h"
#include "HwcComposer2D.h"
#include "mozilla/layers/LayerManagerComposite.h"
#include "mozilla/layers/PLayerTransaction.h"
#include "mozilla/layers/ShadowLayerUtilsGralloc.h"
#include "mozilla/StaticPtr.h"
#include "cutils/properties.h"
#include "gfxUtils.h"

#define LOG_TAG "HWComposer"

#if (LOG_NDEBUG == 0)
#define LOGD(args...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, ## args)
#else
#define LOGD(args...) ((void)0)
#endif

#define LOGE(args...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, ## args)

#define LAYER_COUNT_INCREMENTS 5

using namespace android;
using namespace mozilla::layers;

enum {
    HWC_USE_GPU = HWC_FRAMEBUFFER,
    HWC_USE_OVERLAY = HWC_OVERLAY,
    HWC_USE_COPYBIT
};

// HWC layer flags
enum {
    // Draw a solid color rectangle
    // The color should be set on the transform member of the hwc_layer_t struct
    // The expected format is a 32 bit ABGR with 8 bits per component
    HWC_COLOR_FILL = 0x8,
    // Swap the RB pixels of gralloc buffer, like RGBA<->BGRA or RGBX<->BGRX
    // The flag will be set inside LayerRenderState
    HWC_FORMAT_RB_SWAP = 0x40
};

namespace mozilla {

static StaticRefPtr<HwcComposer2D> sInstance;

HwcComposer2D::HwcComposer2D()
    : mMaxLayerCount(0)
    , mList(nullptr)
    , mHwc(nullptr)
{
}

HwcComposer2D::~HwcComposer2D() {
    free(mList);
}

int
HwcComposer2D::Init(hwc_display_t dpy, hwc_surface_t sur)
{
    MOZ_ASSERT(!Initialized());

    mHwc = (hwc_composer_device_t*)GetGonkDisplay()->GetHWCDevice();
    if (!mHwc) {
        LOGE("Failed to initialize hwc");
        return -1;
    }

    nsIntSize screenSize;

    mozilla::Framebuffer::GetSize(&screenSize);
    mScreenRect  = nsIntRect(nsIntPoint(0, 0), screenSize);

    char propValue[PROPERTY_VALUE_MAX];
    property_get("ro.display.colorfill", propValue, "0");
    mColorFill = (atoi(propValue) == 1) ? true : false;

    mDpy = dpy;
    mSur = sur;

    return 0;
}

HwcComposer2D*
HwcComposer2D::GetInstance()
{
    if (!sInstance) {
        LOGD("Creating new instance");
        sInstance = new HwcComposer2D();
    }
    return sInstance;
}

bool
HwcComposer2D::ReallocLayerList()
{
    int size = sizeof(hwc_layer_list_t) +
        ((mMaxLayerCount + LAYER_COUNT_INCREMENTS) * sizeof(hwc_layer_t));

    hwc_layer_list_t* listrealloc = (hwc_layer_list_t*)realloc(mList, size);

    if (!listrealloc) {
        return false;
    }

    if (!mList) {
        //first alloc, initialize
        listrealloc->numHwLayers = 0;
        listrealloc->flags = 0;
    }

    mList = listrealloc;
    mMaxLayerCount += LAYER_COUNT_INCREMENTS;
    return true;
}

/**
 * Sets hwc layer rectangles required for hwc composition
 *
 * @param aVisible Input. Layer's unclipped visible rectangle
 *        The origin is the top-left corner of the layer
 * @param aTransform Input. Layer's transformation matrix
 *        It transforms from layer space to screen space
 * @param aClip Input. A clipping rectangle.
 *        The origin is the top-left corner of the screen
 * @param aBufferRect Input. The layer's buffer bounds
 *        The origin is the top-left corner of the layer
 * @param aSurceCrop Output. Area of the source to consider,
 *        the origin is the top-left corner of the buffer
 * @param aVisibleRegionScreen Output. Visible region in screen space.
 *        The origin is the top-left corner of the screen
 * @return true if the layer should be rendered.
 *         false if the layer can be skipped
 */
static bool
PrepareLayerRects(nsIntRect aVisible, const gfxMatrix& aTransform,
                  nsIntRect aClip, nsIntRect aBufferRect,
                  hwc_rect_t* aSourceCrop, hwc_rect_t* aVisibleRegionScreen) {

    gfxRect visibleRect(aVisible);
    gfxRect clip(aClip);
    gfxRect visibleRectScreen = aTransform.TransformBounds(visibleRect);
    // |clip| is guaranteed to be integer
    visibleRectScreen.IntersectRect(visibleRectScreen, clip);

    if (visibleRectScreen.IsEmpty()) {
        LOGD("Skip layer");
        return false;
    }

    gfxMatrix inverse(aTransform);
    inverse.Invert();
    gfxRect crop = inverse.TransformBounds(visibleRectScreen);

    //clip to buffer size
    crop.IntersectRect(crop, aBufferRect);
    crop.Round();

    if (crop.IsEmpty()) {
        LOGD("Skip layer");
        return false;
    }

    //propagate buffer clipping back to visible rect
    visibleRectScreen = aTransform.TransformBounds(crop);
    visibleRectScreen.Round();

    // Map from layer space to buffer space
    crop -= aBufferRect.TopLeft();

    aSourceCrop->left = crop.x;
    aSourceCrop->top  = crop.y;
    aSourceCrop->right  = crop.x + crop.width;
    aSourceCrop->bottom = crop.y + crop.height;

    aVisibleRegionScreen->left = visibleRectScreen.x;
    aVisibleRegionScreen->top  = visibleRectScreen.y;
    aVisibleRegionScreen->right  = visibleRectScreen.x + visibleRectScreen.width;
    aVisibleRegionScreen->bottom = visibleRectScreen.y + visibleRectScreen.height;

    return true;
}

/**
 * Prepares hwc layer visible region required for hwc composition
 *
 * @param aVisible Input. Layer's unclipped visible region
 *        The origin is the top-left corner of the layer
 * @param aTransform Input. Layer's transformation matrix
 *        It transforms from layer space to screen space
 * @param aClip Input. A clipping rectangle.
 *        The origin is the top-left corner of the screen
 * @param aBufferRect Input. The layer's buffer bounds
 *        The origin is the top-left corner of the layer
 * @param aVisibleRegionScreen Output. Visible region in screen space.
 *        The origin is the top-left corner of the screen
 * @return true if the layer should be rendered.
 *         false if the layer can be skipped
 */
static bool
PrepareVisibleRegion(const nsIntRegion& aVisible,
                     const gfxMatrix& aTransform,
                     nsIntRect aClip, nsIntRect aBufferRect,
                     RectVector* aVisibleRegionScreen) {

    nsIntRegionRectIterator rect(aVisible);
    bool isVisible = false;
    while (const nsIntRect* visibleRect = rect.Next()) {
        hwc_rect_t visibleRectScreen;
        gfxRect screenRect;

        screenRect.IntersectRect(gfxRect(*visibleRect), aBufferRect);
        screenRect = aTransform.TransformBounds(screenRect);
        screenRect.IntersectRect(screenRect, aClip);
        screenRect.Round();
        if (screenRect.IsEmpty()) {
            continue;
        }
        visibleRectScreen.left = screenRect.x;
        visibleRectScreen.top  = screenRect.y;
        visibleRectScreen.right  = screenRect.XMost();
        visibleRectScreen.bottom = screenRect.YMost();
        aVisibleRegionScreen->push_back(visibleRectScreen);
        isVisible = true;
    }

    return isVisible;
}

/**
 * Calculates the layer's clipping rectangle
 *
 * @param aTransform Input. A transformation matrix
 *        It transforms the clip rect to screen space
 * @param aLayerClip Input. The layer's internal clipping rectangle.
 *        This may be NULL which means the layer has no internal clipping
 *        The origin is the top-left corner of the layer
 * @param aParentClip Input. The parent layer's rendering clipping rectangle
 *        The origin is the top-left corner of the screen
 * @param aRenderClip Output. The layer's rendering clipping rectangle
 *        The origin is the top-left corner of the screen
 * @return true if the layer should be rendered.
 *         false if the layer can be skipped
 */
static bool
CalculateClipRect(const gfxMatrix& aTransform, const nsIntRect* aLayerClip,
                  nsIntRect aParentClip, nsIntRect* aRenderClip) {

    *aRenderClip = aParentClip;

    if (!aLayerClip) {
        return true;
    }

    if (aLayerClip->IsEmpty()) {
        return false;
    }

    nsIntRect clip = *aLayerClip;

    gfxRect r(clip);
    gfxRect trClip = aTransform.TransformBounds(r);
    trClip.Round();
    gfxUtils::GfxRectToIntRect(trClip, &clip);

    aRenderClip->IntersectRect(*aRenderClip, clip);
    return true;
}

bool
HwcComposer2D::PrepareLayerList(Layer* aLayer,
                                const nsIntRect& aClip,
                                const gfxMatrix& aParentTransform,
                                const gfxMatrix& aGLWorldTransform)
{
    // NB: we fall off this path whenever there are container layers
    // that require intermediate surfaces.  That means all the
    // GetEffective*() coordinates are relative to the framebuffer.

    bool fillColor = false;

    const nsIntRegion& visibleRegion = aLayer->GetEffectiveVisibleRegion();
    if (visibleRegion.IsEmpty()) {
        return true;
    }

    float opacity = aLayer->GetEffectiveOpacity();
    if (opacity < 1) {
        LOGD("%s Layer has planar semitransparency which is unsupported", aLayer->Name());
        return false;
    }

    nsIntRect clip;
    if (!CalculateClipRect(aParentTransform * aGLWorldTransform,
                           aLayer->GetEffectiveClipRect(),
                           aClip,
                           &clip))
    {
        LOGD("%s Clip rect is empty. Skip layer", aLayer->Name());
        return true;
    }

    gfxMatrix transform;
    const gfx3DMatrix& transform3D = aLayer->GetEffectiveTransform();
    if (!transform3D.Is2D(&transform) || !transform.PreservesAxisAlignedRectangles()) {
        LOGD("Layer has a 3D transform or a non-square angle rotation");
        return false;
    }


    if (ContainerLayer* container = aLayer->AsContainerLayer()) {
        if (container->UseIntermediateSurface()) {
            LOGD("Container layer needs intermediate surface");
            return false;
        }
        nsAutoTArray<Layer*, 12> children;
        container->SortChildrenBy3DZOrder(children);

        for (uint32_t i = 0; i < children.Length(); i++) {
            if (!PrepareLayerList(children[i], clip, transform, aGLWorldTransform)) {
                return false;
            }
        }
        return true;
    }

    LayerRenderState state = aLayer->GetRenderState();
    nsIntSize surfaceSize;

    if (state.mSurface.get()) {
        surfaceSize = state.mSize;
    } else {
        if (aLayer->AsColorLayer() && mColorFill) {
            fillColor = true;
        } else {
            LOGD("%s Layer doesn't have a gralloc buffer", aLayer->Name());
            return false;
        }
    }
    if (state.BufferRotated()) {
        LOGD("%s Layer has a rotated buffer", aLayer->Name());
        return false;
    }


    // OK!  We can compose this layer with hwc.

    int current = mList ? mList->numHwLayers : 0;
    if (!mList || current >= mMaxLayerCount) {
        if (!ReallocLayerList() || current >= mMaxLayerCount) {
            LOGE("PrepareLayerList failed! Could not increase the maximum layer count");
            return false;
        }
    }

    nsIntRect visibleRect = visibleRegion.GetBounds();

    nsIntRect bufferRect;
    if (fillColor) {
        bufferRect = nsIntRect(visibleRect);
    } else {
        if(state.mHasOwnOffset) {
            bufferRect = nsIntRect(state.mOffset.x, state.mOffset.y,
                                   state.mSize.width, state.mSize.height);
        } else {
            //Since the buffer doesn't have its own offset, assign the whole
            //surface size as its buffer bounds
            bufferRect = nsIntRect(0, 0, state.mSize.width, state.mSize.height);
        }
    }

    hwc_layer_t& hwcLayer = mList->hwLayers[current];

    if(!PrepareLayerRects(visibleRect,
                          transform * aGLWorldTransform,
                          clip,
                          bufferRect,
                          &(hwcLayer.sourceCrop),
                          &(hwcLayer.displayFrame)))
    {
        return true;
    }

    buffer_handle_t handle = fillColor ? nullptr : state.mSurface->getNativeBuffer()->handle;
    hwcLayer.handle = handle;

    hwcLayer.flags = 0;
    hwcLayer.hints = 0;
    hwcLayer.blending = HWC_BLENDING_PREMULT;
    hwcLayer.compositionType = HWC_USE_COPYBIT;

    if (!fillColor) {
        if (state.FormatRBSwapped()) {
            hwcLayer.flags |= HWC_FORMAT_RB_SWAP;
        }

        gfxMatrix rotation = transform * aGLWorldTransform;
        // Compute fuzzy equal like PreservesAxisAlignedRectangles()
        if (fabs(rotation.xx) < 1e-6) {
            if (rotation.xy < 0) {
                hwcLayer.transform = HWC_TRANSFORM_ROT_90;
                LOGD("Layer buffer rotated 90 degrees");
            } else {
                hwcLayer.transform = HWC_TRANSFORM_ROT_270;
                LOGD("Layer buffer rotated 270 degrees");
            }
        } else if (rotation.xx < 0) {
            hwcLayer.transform = HWC_TRANSFORM_ROT_180;
            LOGD("Layer buffer rotated 180 degrees");
        } else {
            hwcLayer.transform = 0;
        }

        hwcLayer.transform |= state.YFlipped() ? HWC_TRANSFORM_FLIP_V : 0;
        hwc_region_t region;
        if (visibleRegion.GetNumRects() > 1) {
            mVisibleRegions.push_back(RectVector());
            RectVector* visibleRects = &(mVisibleRegions.back());
            if(!PrepareVisibleRegion(visibleRegion,
                                     transform * aGLWorldTransform,
                                     clip,
                                     bufferRect,
                                     visibleRects)) {
                return true;
            }
            region.numRects = visibleRects->size();
            region.rects = &((*visibleRects)[0]);
        } else {
            region.numRects = 1;
            region.rects = &(hwcLayer.displayFrame);
        }
        hwcLayer.visibleRegionScreen = region;
    } else {
        hwcLayer.flags |= HWC_COLOR_FILL;
        ColorLayer* colorLayer = aLayer->AsColorLayer();
        if (colorLayer->GetColor().a < 1.0) {
            LOGD("Color layer has semitransparency which is unsupported");
            return false;
        }
        hwcLayer.transform = colorLayer->GetColor().Packed();
    }

    mList->numHwLayers++;
    return true;
}

bool
HwcComposer2D::TryRender(Layer* aRoot,
                         const gfxMatrix& aGLWorldTransform)
{
    if (!aGLWorldTransform.PreservesAxisAlignedRectangles()) {
        LOGD("Render aborted. World transform has non-square angle rotation");
        return false;
    }

    MOZ_ASSERT(Initialized());
    if (mList) {
        mList->numHwLayers = 0;
    }

    // XXX: The clear() below means all rect vectors will be have to be
    // reallocated. We may want to avoid this if possible
    mVisibleRegions.clear();

    if (!PrepareLayerList(aRoot,
                          mScreenRect,
                          gfxMatrix(),
                          aGLWorldTransform))
    {
        LOGD("Render aborted. Nothing was drawn to the screen");
        return false;
    }

    if (mHwc->set(mHwc, mDpy, mSur, mList)) {
        LOGE("Hardware device failed to render");
        return false;
    }

    LOGD("Frame rendered");
    return true;
}

} // namespace mozilla