/*
 * 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 "GLWebViewState.h"

#if USE(ACCELERATED_COMPOSITING)

#include "BaseLayerAndroid.h"
#include "ClassTracker.h"
#include "GLUtils.h"
#include "ImagesManager.h"
#include "LayerAndroid.h"
#include "SkPath.h"
#include "TilesManager.h"
#include "TilesTracker.h"
#include <wtf/CurrentTime.h>

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

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

#ifdef DEBUG

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

#else

#undef XLOG
#define XLOG(...)

#endif // DEBUG

#define FIRST_TILED_PAGE_ID 1
#define SECOND_TILED_PAGE_ID 2

#define FRAMERATE_CAP 0.01666 // We cap at 60 fps

// log warnings if scale goes outside this range
#define MIN_SCALE_WARNING 0.1
#define MAX_SCALE_WARNING 10

namespace WebCore {

using namespace android;

GLWebViewState::GLWebViewState(android::Mutex* buttonMutex)
    : m_zoomManager(this)
    , m_paintingBaseLayer(0)
    , m_currentBaseLayer(0)
    , m_currentBaseLayerRoot(0)
    , m_currentPictureCounter(0)
    , m_usePageA(true)
    , m_frameworkInval(0, 0, 0, 0)
    , m_frameworkLayersInval(0, 0, 0, 0)
    , m_globalButtonMutex(buttonMutex)
    , m_baseLayerUpdate(true)
    , m_backgroundColor(SK_ColorWHITE)
    , m_isScrolling(false)
    , m_goingDown(true)
    , m_goingLeft(false)
    , m_expandedTileBoundsX(0)
    , m_expandedTileBoundsY(0)
    , m_scale(1)
{
    m_viewport.setEmpty();
    m_futureViewportTileBounds.setEmpty();
    m_viewportTileBounds.setEmpty();
    m_preZoomBounds.setEmpty();

    m_tiledPageA = new TiledPage(FIRST_TILED_PAGE_ID, this);
    m_tiledPageB = new TiledPage(SECOND_TILED_PAGE_ID, this);

#ifdef DEBUG_COUNT
    ClassTracker::instance()->increment("GLWebViewState");
#endif
#ifdef MEASURES_PERF
    m_timeCounter = 0;
    m_totalTimeCounter = 0;
    m_measurePerfs = false;
#endif
}

GLWebViewState::~GLWebViewState()
{
    // Unref the existing tree/PaintedSurfaces
    if (m_currentBaseLayerRoot)
        TilesManager::instance()->swapLayersTextures(m_currentBaseLayerRoot, 0);

    // Take care of the transfer queue such that Tex Gen thread will not stuck
    TilesManager::instance()->unregisterGLWebViewState(this);

    // We have to destroy the two tiled pages first as their destructor
    // may depend on the existence of this GLWebViewState and some of its
    // instance variables in order to complete.
    // Explicitely, currently we need to have the m_paintingBaseLayer around
    // in order to complete any pending paint operations (the tiled pages
    // will remove any pending operations, and wait if one is underway).
    delete m_tiledPageA;
    delete m_tiledPageB;
    SkSafeUnref(m_paintingBaseLayer);
    SkSafeUnref(m_currentBaseLayer);
    SkSafeUnref(m_currentBaseLayerRoot);
    m_paintingBaseLayer = 0;
    m_currentBaseLayer = 0;
    m_currentBaseLayerRoot = 0;
#ifdef DEBUG_COUNT
    ClassTracker::instance()->decrement("GLWebViewState");
#endif

}

void GLWebViewState::setBaseLayer(BaseLayerAndroid* layer, const SkRegion& inval,
                                  bool showVisualIndicator, bool isPictureAfterFirstLayout)
{
    android::Mutex::Autolock lock(m_baseLayerLock);
    if (!layer || isPictureAfterFirstLayout) {
        m_tiledPageA->discardTextures();
        m_tiledPageB->discardTextures();
    }
    if (isPictureAfterFirstLayout) {
        m_baseLayerUpdate = true;
        m_invalidateRegion.setEmpty();
    }

    SkSafeRef(layer);
    SkSafeUnref(m_currentBaseLayer);
    m_currentBaseLayer = layer;


    // copy content from old composited root to new
    LayerAndroid* oldRoot = m_currentBaseLayerRoot;
    if (layer) {
        layer->setGLWebViewState(this);
        m_currentBaseLayerRoot = static_cast<LayerAndroid*>(layer->getChild(0));
        SkSafeRef(m_currentBaseLayerRoot);
    } else {
        m_currentBaseLayerRoot = 0;
    }
    if (oldRoot != m_currentBaseLayerRoot)
        TilesManager::instance()->swapLayersTextures(oldRoot, m_currentBaseLayerRoot);
    SkSafeUnref(oldRoot);

    // We only update the base layer if we are not currently
    // waiting for a tiledPage to be painted
    if (m_baseLayerUpdate) {
        SkSafeRef(layer);
        SkSafeUnref(m_paintingBaseLayer);
        m_paintingBaseLayer = layer;
    }
    m_glExtras.setDrawExtra(0);
    invalRegion(inval);

#ifdef MEASURES_PERF
    if (m_measurePerfs && !showVisualIndicator)
        dumpMeasures();
    m_measurePerfs = showVisualIndicator;
#endif

    TilesManager::instance()->setShowVisualIndicator(showVisualIndicator);
}

void GLWebViewState::invalRegion(const SkRegion& region)
{
    SkRegion::Iterator iterator(region);
    while (!iterator.done()) {
        SkIRect r = iterator.rect();
        IntRect ir(r.fLeft, r.fTop, r.width(), r.height());
        inval(ir);
        iterator.next();
    }
}

void GLWebViewState::unlockBaseLayerUpdate() {
    if (m_baseLayerUpdate)
        return;

    m_baseLayerUpdate = true;
    android::Mutex::Autolock lock(m_baseLayerLock);
    SkSafeRef(m_currentBaseLayer);
    SkSafeUnref(m_paintingBaseLayer);
    m_paintingBaseLayer = m_currentBaseLayer;

    invalRegion(m_invalidateRegion);
    m_invalidateRegion.setEmpty();
}

void GLWebViewState::inval(const IntRect& rect)
{
    if (m_baseLayerUpdate) {
        // base layer isn't locked, so go ahead and issue the inval to both tiled pages
        m_currentPictureCounter++;
        if (!rect.isEmpty()) {
            // find which tiles fall within the invalRect and mark them as dirty
            m_tiledPageA->invalidateRect(rect, m_currentPictureCounter);
            m_tiledPageB->invalidateRect(rect, m_currentPictureCounter);
            if (m_frameworkInval.isEmpty())
                m_frameworkInval = rect;
            else
                m_frameworkInval.unite(rect);
            XLOG("intermediate invalRect(%d, %d, %d, %d) after unite with rect %d %d %d %d", m_frameworkInval.x(),
                 m_frameworkInval.y(), m_frameworkInval.width(), m_frameworkInval.height(),
                 rect.x(), rect.y(), rect.width(), rect.height());
        }
    } else {
        // base layer is locked, so defer invalidation until unlockBaseLayerUpdate()
        m_invalidateRegion.op(rect.x(), rect.y(), rect.maxX(), rect.maxY(), SkRegion::kUnion_Op);
    }
    TilesManager::instance()->getProfiler()->nextInval(rect, zoomManager()->currentScale());
}

unsigned int GLWebViewState::paintBaseLayerContent(SkCanvas* canvas)
{
    android::Mutex::Autolock lock(m_baseLayerLock);
    if (m_paintingBaseLayer) {
        m_globalButtonMutex->lock();
        m_paintingBaseLayer->drawCanvas(canvas);
        m_globalButtonMutex->unlock();
    }
    return m_currentPictureCounter;
}

TiledPage* GLWebViewState::sibling(TiledPage* page)
{
    return (page == m_tiledPageA) ? m_tiledPageB : m_tiledPageA;
}

TiledPage* GLWebViewState::frontPage()
{
    android::Mutex::Autolock lock(m_tiledPageLock);
    return m_usePageA ? m_tiledPageA : m_tiledPageB;
}

TiledPage* GLWebViewState::backPage()
{
    android::Mutex::Autolock lock(m_tiledPageLock);
    return m_usePageA ? m_tiledPageB : m_tiledPageA;
}

void GLWebViewState::swapPages()
{
    android::Mutex::Autolock lock(m_tiledPageLock);
    m_usePageA ^= true;
    TiledPage* oldPage = m_usePageA ? m_tiledPageB : m_tiledPageA;
    zoomManager()->swapPages();
    oldPage->discardTextures();
}

int GLWebViewState::baseContentWidth()
{
    return m_paintingBaseLayer ? m_paintingBaseLayer->content()->width() : 0;
}
int GLWebViewState::baseContentHeight()
{
    return m_paintingBaseLayer ? m_paintingBaseLayer->content()->height() : 0;
}

void GLWebViewState::setViewport(SkRect& viewport, float scale)
{
    if ((m_viewport == viewport) &&
        (zoomManager()->futureScale() == scale))
        return;

    m_goingDown = m_viewport.fTop - viewport.fTop <= 0;
    m_goingLeft = m_viewport.fLeft - viewport.fLeft >= 0;
    m_viewport = viewport;

    XLOG("New VIEWPORT %.2f - %.2f %.2f - %.2f (w: %2.f h: %.2f scale: %.2f currentScale: %.2f futureScale: %.2f)",
         m_viewport.fLeft, m_viewport.fTop, m_viewport.fRight, m_viewport.fBottom,
         m_viewport.width(), m_viewport.height(), scale,
         zoomManager()->currentScale(), zoomManager()->futureScale());

    const float invTileContentWidth = scale / TilesManager::tileWidth();
    const float invTileContentHeight = scale / TilesManager::tileHeight();

    m_viewportTileBounds.set(
            static_cast<int>(floorf(viewport.fLeft * invTileContentWidth)),
            static_cast<int>(floorf(viewport.fTop * invTileContentHeight)),
            static_cast<int>(ceilf(viewport.fRight * invTileContentWidth)),
            static_cast<int>(ceilf(viewport.fBottom * invTileContentHeight)));

    // allocate max possible number of tiles visible with this viewport
    int viewMaxTileX = static_cast<int>(ceilf((viewport.width()-1) * invTileContentWidth)) + 1;
    int viewMaxTileY = static_cast<int>(ceilf((viewport.height()-1) * invTileContentHeight)) + 1;
    int maxTextureCount = (viewMaxTileX + TILE_PREFETCH_DISTANCE * 2) *
        (viewMaxTileY + TILE_PREFETCH_DISTANCE * 2) * 2;
    TilesManager::instance()->setMaxTextureCount(maxTextureCount);
    m_tiledPageA->updateBaseTileSize();
    m_tiledPageB->updateBaseTileSize();
}

#ifdef MEASURES_PERF
void GLWebViewState::dumpMeasures()
{
    for (int i = 0; i < m_timeCounter; i++) {
        XLOGC("%d delay: %d ms", m_totalTimeCounter + i,
             static_cast<int>(m_delayTimes[i]*1000));
        m_delayTimes[i] = 0;
    }
    m_totalTimeCounter += m_timeCounter;
    m_timeCounter = 0;
}
#endif // MEASURES_PERF

void GLWebViewState::resetFrameworkInval()
{
    m_frameworkInval.setX(0);
    m_frameworkInval.setY(0);
    m_frameworkInval.setWidth(0);
    m_frameworkInval.setHeight(0);
}

void GLWebViewState::addDirtyArea(const IntRect& rect)
{
    if (rect.isEmpty())
        return;

    IntRect inflatedRect = rect;
    inflatedRect.inflate(8);
    if (m_frameworkLayersInval.isEmpty())
        m_frameworkLayersInval = inflatedRect;
    else
        m_frameworkLayersInval.unite(inflatedRect);
}

void GLWebViewState::resetLayersDirtyArea()
{
    m_frameworkLayersInval.setX(0);
    m_frameworkLayersInval.setY(0);
    m_frameworkLayersInval.setWidth(0);
    m_frameworkLayersInval.setHeight(0);
}

double GLWebViewState::setupDrawing(IntRect& viewRect, SkRect& visibleRect,
                                  IntRect& webViewRect, int titleBarHeight,
                                  IntRect& screenClip, float scale)
{
    int left = viewRect.x();
    int top = viewRect.y();
    int width = viewRect.width();
    int height = viewRect.height();

    if (TilesManager::instance()->invertedScreen()) {
        float color = 1.0 - ((((float) m_backgroundColor.red() / 255.0) +
                      ((float) m_backgroundColor.green() / 255.0) +
                      ((float) m_backgroundColor.blue() / 255.0)) / 3.0);
        glClearColor(color, color, color, 1);
    } else {
        glClearColor((float)m_backgroundColor.red() / 255.0,
                     (float)m_backgroundColor.green() / 255.0,
                     (float)m_backgroundColor.blue() / 255.0, 1);
    }
    glClear(GL_COLOR_BUFFER_BIT);

    glViewport(left, top, width, height);

    ShaderProgram* shader = TilesManager::instance()->shader();
    if (shader->program() == -1) {
        XLOG("Reinit shader");
        shader->init();
    }
    shader->setViewRect(viewRect);
    shader->setViewport(visibleRect);
    shader->setWebViewRect(webViewRect);
    shader->setTitleBarHeight(titleBarHeight);
    shader->setScreenClip(screenClip);
    shader->resetBlending();

    double currentTime = WTF::currentTime();

    setViewport(visibleRect, scale);
    m_zoomManager.processNewScale(currentTime, scale);

    return currentTime;
}

bool GLWebViewState::drawGL(IntRect& rect, SkRect& viewport, IntRect* invalRect,
                            IntRect& webViewRect, int titleBarHeight,
                            IntRect& clip, float scale, bool* buffersSwappedPtr)
{
    m_scale = scale;
    TilesManager::instance()->getProfiler()->nextFrame(viewport.fLeft,
                                                       viewport.fTop,
                                                       viewport.fRight,
                                                       viewport.fBottom,
                                                       scale);
    TilesManager::instance()->incDrawGLCount();

#ifdef DEBUG
    TilesManager::instance()->getTilesTracker()->clear();
#endif

    m_baseLayerLock.lock();
    BaseLayerAndroid* baseLayer = m_paintingBaseLayer;
    SkSafeRef(baseLayer);
    m_baseLayerLock.unlock();
    if (!baseLayer)
         return false;

    float viewWidth = (viewport.fRight - viewport.fLeft) * TILE_PREFETCH_RATIO;
    float viewHeight = (viewport.fBottom - viewport.fTop) * TILE_PREFETCH_RATIO;
    bool useHorzPrefetch = viewWidth < baseContentWidth();
    bool useVertPrefetch = viewHeight < baseContentHeight();
    m_expandedTileBoundsX = (useHorzPrefetch) ? TILE_PREFETCH_DISTANCE : 0;
    m_expandedTileBoundsY = (useVertPrefetch) ? TILE_PREFETCH_DISTANCE : 0;

    XLOG("drawGL, rect(%d, %d, %d, %d), viewport(%.2f, %.2f, %.2f, %.2f)",
         rect.x(), rect.y(), rect.width(), rect.height(),
         viewport.fLeft, viewport.fTop, viewport.fRight, viewport.fBottom);

    resetLayersDirtyArea();

    LayerAndroid* compositedRoot = m_currentBaseLayerRoot;
    LayerAndroid* paintingBaseLayerRoot = 0;
    if (baseLayer && baseLayer->countChildren() >= 1)
        paintingBaseLayerRoot = static_cast<LayerAndroid*>(baseLayer->getChild(0));

    // when adding or removing layers, use the the paintingBaseLayer's tree so
    // that content that moves to the base layer from a layer is synchronized
    bool paintingHasLayers = (paintingBaseLayerRoot == 0);
    bool currentHasLayers = (m_currentBaseLayerRoot == 0);
    if (paintingHasLayers != currentHasLayers)
        compositedRoot = paintingBaseLayerRoot;

    if (scale < MIN_SCALE_WARNING || scale > MAX_SCALE_WARNING)
        XLOGC("WARNING, scale seems corrupted before update: %e", scale);

    // Here before we draw, update the BaseTile which has updated content.
    // Inside this function, just do GPU blits from the transfer queue into
    // the BaseTiles' texture.
    TilesManager::instance()->transferQueue()->updateDirtyBaseTiles();

    // Upload any pending ImageTexture
    // Return true if we still have some images to upload.
    // TODO: upload as many textures as possible within a certain time limit
    bool ret = ImagesManager::instance()->uploadTextures();

    if (scale < MIN_SCALE_WARNING || scale > MAX_SCALE_WARNING) {
        XLOGC("WARNING, scale seems corrupted after update: %e", scale);
        CRASH();
    }

    // gather the textures we can use
    TilesManager::instance()->gatherLayerTextures();

    // set up zoom manager, shaders, etc.
    m_backgroundColor = baseLayer->getBackgroundColor();
    double currentTime = setupDrawing(rect, viewport, webViewRect, titleBarHeight, clip, scale);
    ret |= baseLayer->drawGL(currentTime, compositedRoot, rect,
                                 viewport, scale, buffersSwappedPtr);
    m_glExtras.drawGL(webViewRect, viewport, titleBarHeight);

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    ret |= TilesManager::instance()->invertedScreenSwitch();

    if (ret) {
        // ret==true && empty inval region means we've inval'd everything,
        // but don't have new content. Keep redrawing full view (0,0,0,0)
        // until tile generation catches up and we swap pages.
        bool fullScreenInval = m_frameworkInval.isEmpty();

        if (TilesManager::instance()->invertedScreenSwitch()) {
            fullScreenInval = true;
            TilesManager::instance()->setInvertedScreenSwitch(false);
        }

        if (!fullScreenInval) {
            FloatRect frameworkInval = TilesManager::instance()->shader()->rectInInvScreenCoord(
                    m_frameworkInval);
            // Inflate the invalidate rect to avoid precision lost.
            frameworkInval.inflate(1);
            IntRect inval(frameworkInval.x(), frameworkInval.y(),
                    frameworkInval.width(), frameworkInval.height());

            inval.unite(m_frameworkLayersInval);

            invalRect->setX(inval.x());
            invalRect->setY(inval.y());
            invalRect->setWidth(inval.width());
            invalRect->setHeight(inval.height());

            XLOG("invalRect(%d, %d, %d, %d)", inval.x(),
                    inval.y(), inval.width(), inval.height());

            if (!invalRect->intersects(rect)) {
                // invalidate is occurring offscreen, do full inval to guarantee redraw
                fullScreenInval = true;
            }
        }

        if (fullScreenInval) {
            invalRect->setX(0);
            invalRect->setY(0);
            invalRect->setWidth(0);
            invalRect->setHeight(0);
        }
    } else {
        resetFrameworkInval();
    }

#ifdef MEASURES_PERF
    if (m_measurePerfs) {
        m_delayTimes[m_timeCounter++] = delta;
        if (m_timeCounter >= MAX_MEASURES_PERF)
            dumpMeasures();
    }
#endif

    SkSafeUnref(baseLayer);
#ifdef DEBUG
    TilesManager::instance()->getTilesTracker()->showTrackTextures();
    ImagesManager::instance()->showImages();
#endif
    return ret;
}

} // namespace WebCore

#endif // USE(ACCELERATED_COMPOSITING)