/*
 * 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 "BaseLayerAndroid.h"

#if USE(ACCELERATED_COMPOSITING)
#include "ClassTracker.h"
#include "GLUtils.h"
#include "ShaderProgram.h"
#include "SkCanvas.h"
#include "TilesManager.h"
#include <GLES2/gl2.h>
#include <wtf/CurrentTime.h>
#endif // USE(ACCELERATED_COMPOSITING)

#ifdef DEBUG

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

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

#else

#undef XLOG
#define XLOG(...)

#endif // DEBUG

namespace WebCore {

using namespace android;

BaseLayerAndroid::BaseLayerAndroid()
#if USE(ACCELERATED_COMPOSITING)
    : m_glWebViewState(0),
      m_color(Color::white)
#endif
{
#ifdef DEBUG_COUNT
    ClassTracker::instance()->increment("BaseLayerAndroid");
#endif
}

BaseLayerAndroid::~BaseLayerAndroid()
{
#if USE(ACCELERATED_COMPOSITING)
    if (TilesManager::hardwareAccelerationEnabled())
        TilesManager::instance()->removeOperationsForBaseLayer(this);
#endif
    m_content.clear();
#ifdef DEBUG_COUNT
    ClassTracker::instance()->decrement("BaseLayerAndroid");
#endif
}

void BaseLayerAndroid::setContent(const PictureSet& src)
{
#if USE(ACCELERATED_COMPOSITING)
    // FIXME: We lock here because we do not want
    // to paint and change the m_content concurrently.
    // We should instead refactor PictureSet to use
    // an atomic refcounting scheme and use atomic operations
    // to swap PictureSets.
    android::Mutex::Autolock lock(m_drawLock);
#endif
    m_content.set(src);
    // FIXME: We cannot set the size of the base layer because it will screw up
    // the matrix used.  We need to fix matrix computation for the base layer
    // and then we can set the size.
    // setSize(src.width(), src.height());
}

void BaseLayerAndroid::setExtra(SkPicture& src)
{
#if USE(ACCELERATED_COMPOSITING)
    android::Mutex::Autolock lock(m_drawLock);
#endif
    m_extra.swap(src);
}

void BaseLayerAndroid::drawCanvas(SkCanvas* canvas)
{
#if USE(ACCELERATED_COMPOSITING)
    android::Mutex::Autolock lock(m_drawLock);
#endif
    if (!m_content.isEmpty())
        m_content.draw(canvas);
    // TODO : replace with !m_extra.isEmpty() once such a call exists
    if (m_extra.width() > 0)
        m_extra.draw(canvas);
}

#if USE(ACCELERATED_COMPOSITING)
bool BaseLayerAndroid::drawBasePictureInGL(SkRect& viewport, float scale, double currentTime)
{
    if (!m_glWebViewState)
        return false;

    bool goingDown = m_previousVisible.fTop - viewport.fTop <= 0;
    bool goingLeft = m_previousVisible.fLeft - viewport.fLeft >= 0;

    m_glWebViewState->setViewport(viewport, scale);

    const SkIRect& viewportTileBounds = m_glWebViewState->viewportTileBounds();
    XLOG("drawBasePicture, TX: %d, TY: %d scale %.2f", viewportTileBounds.fLeft,
            viewportTileBounds.fTop, scale);

    if (scale == m_glWebViewState->currentScale()
        || m_glWebViewState->preZoomBounds().isEmpty())
        m_glWebViewState->setPreZoomBounds(viewportTileBounds);

    bool prepareNextTiledPage = false;
    // If we have a different scale than the current one, we have to
    // decide what to do. The current behaviour is to delay an update,
    // so that we do not slow down zooming unnecessarily.
    if ((m_glWebViewState->currentScale() != scale && (m_glWebViewState->scaleRequestState() == GLWebViewState::kNoScaleRequest || m_glWebViewState->futureScale() != scale))
        || m_glWebViewState->scaleRequestState() == GLWebViewState::kWillScheduleRequest) {

        // schedule the new request
        m_glWebViewState->scheduleUpdate(currentTime, viewportTileBounds, scale);

        // If it's a new request, we will have to prepare the page.
        if (m_glWebViewState->scaleRequestState() == GLWebViewState::kRequestNewScale)
            prepareNextTiledPage = true;
    }

    // If the viewport has changed since we scheduled the request, we also need to prepare.
    if ((m_glWebViewState->scaleRequestState() == GLWebViewState::kRequestNewScale || m_glWebViewState->scaleRequestState() == GLWebViewState::kReceivedNewScale)
        && m_glWebViewState->futureViewport() != viewportTileBounds)
        prepareNextTiledPage = true;

    bool zooming = false;
    if (m_glWebViewState->scaleRequestState() != GLWebViewState::kNoScaleRequest) {
        prepareNextTiledPage = true;
        zooming = true;
    }

    // Display the current page
    TiledPage* tiledPage = m_glWebViewState->frontPage();
    tiledPage->setScale(m_glWebViewState->currentScale());

    // Let's prepare the page if needed
    if (prepareNextTiledPage) {
        TiledPage* nextTiledPage = m_glWebViewState->backPage();
        nextTiledPage->setScale(scale);
        m_glWebViewState->setFutureViewport(viewportTileBounds);
        m_glWebViewState->lockBaseLayerUpdate();
        nextTiledPage->prepare(goingDown, goingLeft, viewportTileBounds);
        // Cancel pending paints for the foreground page
        TilesManager::instance()->removePaintOperationsForPage(tiledPage, false);
    }

    float transparency = 1;
    bool doSwap = false;

    // If we fired a request, let's check if it's ready to use
    if (m_glWebViewState->scaleRequestState() == GLWebViewState::kRequestNewScale) {
        TiledPage* nextTiledPage = m_glWebViewState->backPage();
        if (nextTiledPage->ready(viewportTileBounds, m_glWebViewState->futureScale()))
            m_glWebViewState->setScaleRequestState(GLWebViewState::kReceivedNewScale);
    }

    // If the page is ready, display it. We do a short transition between
    // the two pages (current one and future one with the new scale factor)
    if (m_glWebViewState->scaleRequestState() == GLWebViewState::kReceivedNewScale) {
        TiledPage* nextTiledPage = m_glWebViewState->backPage();
        double transitionTime = (scale < m_glWebViewState->currentScale()) ?
            m_glWebViewState->zoomOutTransitionTime(currentTime) :
            m_glWebViewState->zoomInTransitionTime(currentTime);

        float newTilesTransparency = 1;
        if (scale < m_glWebViewState->currentScale())
            newTilesTransparency = 1 - m_glWebViewState->zoomOutTransparency(currentTime);
        else
            transparency = m_glWebViewState->zoomInTransparency(currentTime);

        nextTiledPage->draw(newTilesTransparency, viewportTileBounds);

        // The transition between the two pages is finished, swap them
        if (currentTime > transitionTime) {
            m_glWebViewState->resetTransitionTime();
            doSwap = true;
        }
    }

    const SkIRect& preZoomBounds = m_glWebViewState->preZoomBounds();

    TiledPage* nextTiledPage = m_glWebViewState->backPage();
    bool needsRedraw = false;

    // We are now using an hybrid model -- during scrolling,
    // we will display the current tiledPage even if some tiles are
    // out of date. When standing still on the other hand, we wait until
    // the back page is ready before swapping the pages, ensuring that the
    // displayed content is in sync.
    if (!doSwap && !zooming && !m_glWebViewState->moving()) {
        if (!tiledPage->ready(preZoomBounds, m_glWebViewState->currentScale())) {
            m_glWebViewState->lockBaseLayerUpdate();
            nextTiledPage->setScale(m_glWebViewState->currentScale());
            nextTiledPage->prepare(goingDown, goingLeft, preZoomBounds);
        }
        if (nextTiledPage->ready(preZoomBounds, m_glWebViewState->currentScale())) {
            nextTiledPage->draw(transparency, preZoomBounds);
            m_glWebViewState->resetFrameworkInval();
            m_glWebViewState->unlockBaseLayerUpdate();
            doSwap = true;
        } else {
            tiledPage->draw(transparency, preZoomBounds);
        }
    } else {
        if (tiledPage->ready(preZoomBounds, m_glWebViewState->currentScale()))
           m_glWebViewState->resetFrameworkInval();

        // Ask for the tiles and draw -- tiles may be out of date.
        if (!zooming)
           m_glWebViewState->unlockBaseLayerUpdate();

        if (!prepareNextTiledPage)
            tiledPage->prepare(goingDown, goingLeft, preZoomBounds);
        tiledPage->draw(transparency, preZoomBounds);
    }

    if (m_glWebViewState->scaleRequestState() != GLWebViewState::kNoScaleRequest
        || !tiledPage->ready(preZoomBounds, m_glWebViewState->currentScale()))
        needsRedraw = true;

    if (doSwap) {
        m_glWebViewState->setCurrentScale(scale);
        m_glWebViewState->swapPages();
        m_glWebViewState->unlockBaseLayerUpdate();
    }

    m_glWebViewState->paintExtras();
    return needsRedraw;
}
#endif // USE(ACCELERATED_COMPOSITING)

bool BaseLayerAndroid::drawGL(LayerAndroid* compositedRoot,
                              IntRect& viewRect, SkRect& visibleRect,
                              IntRect& webViewRect, int titleBarHeight,
                              IntRect& screenClip, float scale, SkColor color)
{
    bool needsRedraw = false;
#if USE(ACCELERATED_COMPOSITING)
    int left = viewRect.x();
    int top = viewRect.y();
    int width = viewRect.width();
    int height = viewRect.height();
    XLOG("drawBasePicture drawGL() viewRect: %d, %d, %d, %d - %.2f",
         left, top, width, height, scale);

    m_glWebViewState->setBackgroundColor(color);
    glClearColor((float)m_color.red() / 255.0,
                 (float)m_color.green() / 255.0,
                 (float)m_color.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();
    }
    glUseProgram(shader->program());
    glUniform1i(shader->textureSampler(), 0);
    shader->setViewRect(viewRect);
    shader->setViewport(visibleRect);
    shader->setWebViewRect(webViewRect);
    shader->setTitleBarHeight(titleBarHeight);
    shader->setScreenClip(screenClip);
    shader->resetBlending();

    double currentTime = WTF::currentTime();
    needsRedraw = drawBasePictureInGL(visibleRect, scale, currentTime);
    if (!needsRedraw)
        m_glWebViewState->resetFrameworkInval();

    if (compositedRoot) {
        TransformationMatrix ident;

        bool animsRunning = compositedRoot->evaluateAnimations();
        if (animsRunning)
            needsRedraw = true;

        compositedRoot->updateFixedLayersPositions(visibleRect);
        FloatRect clip(0, 0, viewRect.width(), viewRect.height());
        compositedRoot->updateGLPositions(ident, clip, 1);
        SkMatrix matrix;
        matrix.setTranslate(left, top);

        // At this point, the previous LayerAndroid* root has been destroyed,
        // which will have removed the layers as owners of the textures.
        // Let's now do a pass to reserve the textures for the current tree;
        // it will only reserve existing textures, not create them on demand.
#ifdef DEBUG
        TilesManager::instance()->printLayersTextures("reserve");
#endif
        // Get the current scale; if we are zooming, we don't change the scale
        // factor immediately (see BaseLayerAndroid::drawBasePictureInGL()), but
        // we change the scaleRequestState. When the state is kReceivedNewScale
        // we can use the future scale instead of the current scale to request
        // new textures. After a transition time, the scaleRequestState will be
        // reset and the current scale will be set to the future scale.
        float scale = m_glWebViewState->currentScale();
        if (m_glWebViewState->scaleRequestState() == GLWebViewState::kReceivedNewScale) {
            scale = m_glWebViewState->futureScale();
        }
        bool fullSetup = true;
        if ((m_glWebViewState->previouslyUsedRoot() == compositedRoot) &&
            (compositedRoot->getScale() == scale) &&
            (!m_glWebViewState->moving()))
            fullSetup = false;

        compositedRoot->setScale(scale);

        if (fullSetup) {
            compositedRoot->computeTextureSize(currentTime);
            compositedRoot->reserveGLTextures();

#ifdef DEBUG
            int size = compositedRoot->countTextureSize();
            int nbLayers = compositedRoot->nbLayers();
            XLOG("We are using %d Mb for %d layers", size / 1024 / 1024, nbLayers);
            compositedRoot->showLayers();
#endif
            // Now that we marked the textures being used, we delete
            // the unnecessary ones to make space...
            TilesManager::instance()->cleanupLayersTextures(compositedRoot);
        }
        // Clean up GL textures for video layer.
        TilesManager::instance()->videoLayerManager()->deleteUnusedTextures();

        // Finally do another pass to create new textures and schedule
        // repaints if needed
        compositedRoot->createGLTextures();

        if (compositedRoot->drawGL(m_glWebViewState, matrix))
            needsRedraw = true;
        else if (!animsRunning)
            m_glWebViewState->resetLayersDirtyArea();

    } else {
        TilesManager::instance()->cleanupLayersTextures(0);
    }

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    m_previousVisible = visibleRect;

#endif // USE(ACCELERATED_COMPOSITING)
#ifdef DEBUG
    ClassTracker::instance()->show();
#endif
    return needsRedraw;
}

} // namespace WebCore