/*
 * Copyright 2010, The Android Open Source Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "TilesManager.h"

#if USE(ACCELERATED_COMPOSITING)

#include "BaseTile.h"
#include "PaintedSurface.h"
#include "SkCanvas.h"
#include "SkDevice.h"
#include "SkPaint.h"
#include <android/native_window.h>
#include <cutils/atomic.h>
#include <gui/SurfaceTexture.h>
#include <gui/SurfaceTextureClient.h>


#include <cutils/log.h>
#include <wtf/CurrentTime.h>
#include <wtf/text/CString.h>

#undef XLOGC
#define XLOGC(...) android_printLog(ANDROID_LOG_DEBUG, "TilesManager", __VA_ARGS__)

#ifdef DEBUG

#undef XLOG
#define XLOG(...) android_printLog(ANDROID_LOG_DEBUG, "TilesManager", __VA_ARGS__)

#else

#undef XLOG
#define XLOG(...)

#endif // DEBUG

// Important: We need at least twice as many textures as is needed to cover
// one viewport, otherwise the allocation may stall.
// We need n textures for one TiledPage, and another n textures for the
// second page used when scaling.
// In our case, we use 256*256 textures. On the tablet, this equates to
// at least 60 textures, or 112 with expanded tile boundaries.
// 112(tiles)*256*256*4(bpp)*2(pages) = 56MB
#define MAX_TEXTURE_ALLOCATION ((6+TILE_PREFETCH_DISTANCE*2)*(5+TILE_PREFETCH_DISTANCE*2)*2)
#define TILE_WIDTH 256
#define TILE_HEIGHT 256
#define LAYER_TILE_WIDTH 256
#define LAYER_TILE_HEIGHT 256
#define LAYER_TILES 50

// Define a maximum amount of ram used by layers
#define MAX_LAYERS_ALLOCATION 33554432 // 32Mb
// Define a maximum amount of ram used by one layer
#define MAX_LAYER_ALLOCATION 8388608 // 8Mb
#define BYTES_PER_PIXEL 4 // 8888 config

namespace WebCore {

GLint TilesManager::getMaxTextureSize()
{
    static GLint maxTextureSize = 0;
    if (!maxTextureSize)
        glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
    return maxTextureSize;
}

int TilesManager::getMaxTextureAllocation()
{
    return MAX_TEXTURE_ALLOCATION;
}

TilesManager::TilesManager()
    : m_layersMemoryUsage(0)
    , m_maxTextureCount(0)
    , m_generatorReady(false)
    , m_showVisualIndicator(false)
    , m_invertedScreen(false)
    , m_invertedScreenSwitch(false)
    , m_drawGLCount(0)
{
    XLOG("TilesManager ctor");
    m_textures.reserveCapacity(MAX_TEXTURE_ALLOCATION);
    m_availableTextures.reserveCapacity(MAX_TEXTURE_ALLOCATION);
    m_tilesTextures.reserveCapacity(LAYER_TILES);
    m_availableTilesTextures.reserveCapacity(LAYER_TILES);
    m_pixmapsGenerationThread = new TexturesGenerator();
    m_pixmapsGenerationThread->run("TexturesGenerator");
}

void TilesManager::allocateTiles()
{
    int nbTexturesToAllocate = m_maxTextureCount - m_textures.size();
    XLOG("%d tiles to allocate (%d textures planned)", nbTexturesToAllocate, m_maxTextureCount);
    int nbTexturesAllocated = 0;
    for (int i = 0; i < nbTexturesToAllocate; i++) {
        BaseTileTexture* texture = new BaseTileTexture(
            tileWidth(), tileHeight());
        // the atomic load ensures that the texture has been fully initialized
        // before we pass a pointer for other threads to operate on
        BaseTileTexture* loadedTexture =
            reinterpret_cast<BaseTileTexture*>(
            android_atomic_acquire_load(reinterpret_cast<int32_t*>(&texture)));
        m_textures.append(loadedTexture);
        nbTexturesAllocated++;
    }

    int nbLayersTexturesToAllocate = LAYER_TILES - m_tilesTextures.size();
    XLOG("%d layers tiles to allocate (%d textures planned)", nbLayersTexturesToAllocate, LAYER_TILES);
    int nbLayersTexturesAllocated = 0;
    for (int i = 0; i < nbLayersTexturesToAllocate; i++) {
        BaseTileTexture* texture = new BaseTileTexture(
            layerTileWidth(), layerTileHeight());
        // the atomic load ensures that the texture has been fully initialized
        // before we pass a pointer for other threads to operate on
        BaseTileTexture* loadedTexture =
            reinterpret_cast<BaseTileTexture*>(
            android_atomic_acquire_load(reinterpret_cast<int32_t*>(&texture)));
        m_tilesTextures.append(loadedTexture);
        nbLayersTexturesAllocated++;
    }
    XLOG("allocated %d textures for base (total: %d, %d Mb), %d textures for layers (total: %d, %d Mb)",
         nbTexturesAllocated, m_textures.size(),
         m_textures.size() * TILE_WIDTH * TILE_HEIGHT * 4 / 1024 / 1024,
         nbLayersTexturesAllocated, m_tilesTextures.size(),
         m_tilesTextures.size() * LAYER_TILE_WIDTH * LAYER_TILE_HEIGHT * 4 / 1024 / 1024);
}

void TilesManager::printTextures()
{
#ifdef DEBUG
    XLOG("++++++");
    for (unsigned int i = 0; i < m_textures.size(); i++) {
        BaseTileTexture* texture = m_textures[i];
        BaseTile* o = 0;
        if (texture->owner())
            o = (BaseTile*) texture->owner();
        int x = -1;
        int y = -1;
        if (o) {
            x = o->x();
            y = o->y();
        }
        XLOG("[%d] texture %x  busy: %d owner: %x (%d, %d) page: %x scale: %.2f",
               i, texture,
               texture->busy(), o, x, y, o ? o->page() : 0, o ? o->scale() : 0);
    }
    XLOG("------");
#endif // DEBUG
}

void TilesManager::swapLayersTextures(LayerAndroid* oldTree, LayerAndroid* newTree)
{
    if (oldTree)
        oldTree->assignTextureTo(newTree);

    if (newTree)
        newTree->createTexture();

    WTF::Vector<PaintedSurface*> collect;
    for (unsigned int i = 0; i < m_paintedSurfaces.size(); i++) {
        PaintedSurface* surface = m_paintedSurfaces[i];
        if (!surface->layer())
            collect.append(surface);
    }
    for (unsigned int i = 0; i < collect.size(); i++) {
        m_paintedSurfaces.remove(m_paintedSurfaces.find(collect[i]));
        SkSafeUnref(collect[i]);
    }
}

void TilesManager::addPaintedSurface(PaintedSurface* surface)
{
    m_paintedSurfaces.append(surface);
}

void TilesManager::gatherTextures()
{
    android::Mutex::Autolock lock(m_texturesLock);
    m_availableTextures = m_textures;
}

void TilesManager::gatherLayerTextures()
{
    android::Mutex::Autolock lock(m_texturesLock);
    m_availableTilesTextures = m_tilesTextures;
}

BaseTileTexture* TilesManager::getAvailableTexture(BaseTile* owner)
{
    android::Mutex::Autolock lock(m_texturesLock);

    // Sanity check that the tile does not already own a texture
    if (owner->backTexture() && owner->backTexture()->owner() == owner) {
        XLOG("same owner (%d, %d), getAvailableBackTexture(%x) => texture %x",
             owner->x(), owner->y(), owner, owner->backTexture());
        if (owner->isLayerTile())
            m_availableTilesTextures.remove(m_availableTilesTextures.find(owner->backTexture()));
        else
            m_availableTextures.remove(m_availableTextures.find(owner->backTexture()));
        return owner->backTexture();
    }

    WTF::Vector<BaseTileTexture*>* availableTexturePool;
    if (owner->isLayerTile()) {
        availableTexturePool = &m_availableTilesTextures;
    } else {
        availableTexturePool = &m_availableTextures;
    }

    // The heuristic for selecting a texture is as follows:
    //  1. If a tile isn't owned, break with that one
    //  2. If we find a tile in the same page with a different scale,
    //         it's old and not visible. Break with that one
    //  3. Otherwise, use the least recently prepared tile

    BaseTileTexture* farthestTexture = 0;
    unsigned long long oldestDrawCount = ~0; //maximum u64
    const unsigned int max = availableTexturePool->size();
    for (unsigned int i = 0; i < max; i++) {
        BaseTileTexture* texture = (*availableTexturePool)[i];
        TextureOwner* currentOwner = texture->owner();
        if (!currentOwner) {
            farthestTexture = texture;
            break;
        }

        if (currentOwner->page() == owner->page() && texture->scale() != owner->scale()) {
            // if we render the back page with one scale, then another while
            // still zooming, we recycle the tiles with the old scale instead of
            // taking ones from the front page
            farthestTexture = texture;
            break;
        }

        unsigned long long textureDrawCount = currentOwner->drawCount();
        if (oldestDrawCount > textureDrawCount) {
            farthestTexture = texture;
            oldestDrawCount = textureDrawCount;
        }
    }

    TextureOwner* previousOwner = farthestTexture->owner();
    if (farthestTexture && farthestTexture->acquire(owner)) {
        if (previousOwner) {
            XLOG("%s texture %p stolen from tile %d, %d, drawCount was %llu",
                 owner->isLayerTile() ? "LAYER" : "BASE",
                 farthestTexture, owner->x(), owner->y(), oldestDrawCount);
        }

        availableTexturePool->remove(availableTexturePool->find(farthestTexture));
        return farthestTexture;
    }

    XLOG("Couldn't find an available texture for tile %x (%d, %d) out of %d available!!!",
          owner, owner->x(), owner->y(), max);
#ifdef DEBUG
    printTextures();
#endif // DEBUG
    return 0;
}

int TilesManager::maxLayersAllocation()
{
    return MAX_LAYERS_ALLOCATION;
}

int TilesManager::maxLayerAllocation()
{
    return MAX_LAYER_ALLOCATION;
}

int TilesManager::maxTextureCount()
{
    android::Mutex::Autolock lock(m_texturesLock);
    return m_maxTextureCount;
}

void TilesManager::setMaxTextureCount(int max)
{
    XLOG("setMaxTextureCount: %d (current: %d, total:%d)",
         max, m_maxTextureCount, MAX_TEXTURE_ALLOCATION);
    if (m_maxTextureCount == MAX_TEXTURE_ALLOCATION ||
         max <= m_maxTextureCount)
        return;

    android::Mutex::Autolock lock(m_texturesLock);

    if (max < MAX_TEXTURE_ALLOCATION)
        m_maxTextureCount = max;
    else
        m_maxTextureCount = MAX_TEXTURE_ALLOCATION;

    allocateTiles();
}

float TilesManager::tileWidth()
{
    return TILE_WIDTH;
}

float TilesManager::tileHeight()
{
    return TILE_HEIGHT;
}

float TilesManager::layerTileWidth()
{
    return LAYER_TILE_WIDTH;
}

float TilesManager::layerTileHeight()
{
    return LAYER_TILE_HEIGHT;
}

void TilesManager::unregisterGLWebViewState(GLWebViewState* state)
{
    // Discard the whole queue b/c we lost GL context already.
    // Note the real updateTexImage will still wait for the next draw.
    transferQueue()->discardQueue();
}

TilesManager* TilesManager::instance()
{
    if (!gInstance) {
        gInstance = new TilesManager();
        XLOG("instance(), new gInstance is %x", gInstance);
        XLOG("Waiting for the generator...");
        gInstance->waitForGenerator();
        XLOG("Generator ready!");
    }
    return gInstance;
}

TilesManager* TilesManager::gInstance = 0;

} // namespace WebCore

#endif // USE(ACCELERATED_COMPOSITING)