/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "tools/skiaserve/Request.h"

#include <memory>

#include "include/core/SkBitmap.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkPictureRecorder.h"
#include "include/gpu/GrDirectContext.h"
#include "include/gpu/ganesh/SkSurfaceGanesh.h"
#include "src/utils/SkJSONWriter.h"
#include "tools/ToolUtils.h"
#include "tools/debugger/DrawCommand.h"

using namespace sk_gpu_test;

static int kDefaultWidth = 1920;
static int kDefaultHeight = 1080;
static int kMaxWidth = 8192;
static int kMaxHeight = 8192;


Request::Request(SkString rootUrl)
    : fUploadContext(nullptr)
    , fUrlDataManager(rootUrl)
    , fGPUEnabled(false)
    , fOverdraw(false)
    , fColorMode(0) {
    // create surface
    GrContextOptions grContextOpts;
    fContextFactory = new GrContextFactory(grContextOpts);
}

Request::~Request() {
    if (fContextFactory) {
        delete fContextFactory;
    }
}

sk_sp<SkData> Request::writeCanvasToPng(SkCanvas* canvas) {
    // capture pixels
    SkBitmap bmp;
    bmp.allocPixels(canvas->imageInfo());
    SkAssertResult(canvas->readPixels(bmp, 0, 0));

    // write to an opaque png (black background)
    SkDynamicMemoryWStream buffer;
    DrawCommand::WritePNG(bmp, buffer);
    return buffer.detachAsData();
}

SkCanvas* Request::getCanvas() {
#ifdef SK_GL
    GrContextFactory* factory = fContextFactory;
    GLTestContext* gl = factory->getContextInfo(skgpu::ContextType::kGL,
            GrContextFactory::ContextOverrides::kNone).glContext();
    if (!gl) {
        gl = factory->getContextInfo(skgpu::ContextType::kGLES,
                                     GrContextFactory::ContextOverrides::kNone).glContext();
    }
    if (gl) {
        gl->makeCurrent();
    }
#endif
    SkASSERT(fDebugCanvas);

    // create the appropriate surface if necessary
    if (!fSurface) {
        this->enableGPU(fGPUEnabled);
    }
    SkCanvas* target = fSurface->getCanvas();
    return target;
}

sk_sp<SkData> Request::drawToPng(int n, int m) {
    //fDebugCanvas->setOverdrawViz(true);
    auto* canvas = this->getCanvas();
    canvas->clear(SK_ColorTRANSPARENT);
    fDebugCanvas->drawTo(canvas, n, m);
    //fDebugCanvas->setOverdrawViz(false);
    return writeCanvasToPng(this->getCanvas());
}

sk_sp<SkData> Request::writeOutSkp() {
    // Playback into picture recorder
    SkIRect bounds = this->getBounds();
    SkPictureRecorder recorder;
    SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(bounds.width()),
                                               SkIntToScalar(bounds.height()));

    fDebugCanvas->draw(canvas);

    return recorder.finishRecordingAsPicture()->serialize();
}

GrDirectContext* Request::directContext() {
    auto result = fContextFactory->get(skgpu::ContextType::kGL,
                                       GrContextFactory::ContextOverrides::kNone);
    if (!result) {
        result = fContextFactory->get(skgpu::ContextType::kGLES,
                                      GrContextFactory::ContextOverrides::kNone);
    }
    return result;
}

SkIRect Request::getBounds() {
    SkIRect bounds;
    if (fPicture) {
        bounds = fPicture->cullRect().roundOut();
        if (fGPUEnabled) {
            int maxRTSize = this->directContext()->maxRenderTargetSize();
            bounds = SkIRect::MakeWH(std::min(bounds.width(), maxRTSize),
                                     std::min(bounds.height(), maxRTSize));
        }
    } else {
        bounds = SkIRect::MakeWH(kDefaultWidth, kDefaultHeight);
    }

    // We clip to kMaxWidth / kMaxHeight for performance reasons.
    // TODO make this configurable
    bounds = SkIRect::MakeWH(std::min(bounds.width(), kMaxWidth),
                             std::min(bounds.height(), kMaxHeight));
    return bounds;
}

namespace {

struct ColorAndProfile {
    SkColorType fColorType;
    bool fSRGB;
};

ColorAndProfile ColorModes[] = {
    { kN32_SkColorType,      false },
    { kN32_SkColorType,       true },
    { kRGBA_F16_SkColorType,  true },
};

}  // namespace

SkSurface* Request::createCPUSurface() {
    SkIRect bounds = this->getBounds();
    ColorAndProfile cap = ColorModes[fColorMode];
    auto colorSpace = kRGBA_F16_SkColorType == cap.fColorType
                    ? SkColorSpace::MakeSRGBLinear()
                    : SkColorSpace::MakeSRGB();
    SkImageInfo info = SkImageInfo::Make(bounds.size(), cap.fColorType, kPremul_SkAlphaType,
                                         cap.fSRGB ? colorSpace : nullptr);
    return SkSurfaces::Raster(info).release();
}

SkSurface* Request::createGPUSurface() {
    auto context = this->directContext();
    SkIRect bounds = this->getBounds();
    ColorAndProfile cap = ColorModes[fColorMode];
    auto colorSpace = kRGBA_F16_SkColorType == cap.fColorType
                    ? SkColorSpace::MakeSRGBLinear()
                    : SkColorSpace::MakeSRGB();
    SkImageInfo info = SkImageInfo::Make(bounds.size(), cap.fColorType, kPremul_SkAlphaType,
                                         cap.fSRGB ? colorSpace : nullptr);
    SkSurface* surface = SkSurfaces::RenderTarget(context, skgpu::Budgeted::kNo, info).release();
    return surface;
}

bool Request::setOverdraw(bool enable) {
    fOverdraw = enable;
    return true;
}

bool Request::setColorMode(int mode) {
    fColorMode = mode;
    return enableGPU(fGPUEnabled);
}

bool Request::enableGPU(bool enable) {
    if (enable) {
        SkSurface* surface = this->createGPUSurface();
        if (surface) {
            fSurface.reset(surface);
            fGPUEnabled = true;

            // When we switch to GPU, there seems to be some mystery draws in the canvas.  So we
            // draw once to flush the pipe
            // TODO understand what is actually happening here
            if (fDebugCanvas) {
                fDebugCanvas->drawTo(this->getCanvas(), this->getLastOp());
                this->directContext()->flush(fSurface.get());
            }

            return true;
        }
        return false;
    }
    fSurface.reset(this->createCPUSurface());
    fGPUEnabled = false;
    return true;
}

bool Request::initPictureFromStream(SkStream* stream) {
    // parse picture from stream
    fPicture = SkPicture::MakeFromStream(stream);
    if (!fPicture) {
        fprintf(stderr, "Could not create picture from stream.\n");
        return false;
    }

    // reinitialize canvas with the new picture dimensions
    this->enableGPU(fGPUEnabled);

    // pour picture into debug canvas
    SkIRect bounds = this->getBounds();
    fDebugCanvas = std::make_unique<DebugCanvas>(bounds.width(), bounds.height());
    fDebugCanvas->drawPicture(fPicture);

    // for some reason we need to 'flush' the debug canvas by drawing all of the ops
    fDebugCanvas->drawTo(this->getCanvas(), this->getLastOp());
    this->directContext()->flush(fSurface.get());
    return true;
}

sk_sp<SkData> Request::getJsonOps() {
    SkCanvas* canvas = this->getCanvas();
    SkDynamicMemoryWStream stream;
    SkJSONWriter writer(&stream, SkJSONWriter::Mode::kFast);
    writer.beginObject(); // root

    writer.appendCString("mode", fGPUEnabled ? "gpu" : "cpu");
    writer.appendBool("drawGpuOpBounds", fDebugCanvas->getDrawGpuOpBounds());
    writer.appendS32("colorMode", fColorMode);
    fDebugCanvas->toJSON(writer, fUrlDataManager, canvas);

    writer.endObject(); // root
    writer.flush();
    return stream.detachAsData();
}

sk_sp<SkData> Request::getJsonOpsTask() {
    SkCanvas* canvas = this->getCanvas();
    SkASSERT(fGPUEnabled);
    SkDynamicMemoryWStream stream;
    SkJSONWriter writer(&stream, SkJSONWriter::Mode::kFast);

    fDebugCanvas->toJSONOpsTask(writer, canvas);

    writer.flush();
    return stream.detachAsData();
}

sk_sp<SkData> Request::getJsonInfo(int n) {
    // drawTo
    sk_sp<SkSurface> surface(this->createCPUSurface());
    SkCanvas* canvas = surface->getCanvas();

    // TODO this is really slow and we should cache the matrix and clip
    fDebugCanvas->drawTo(canvas, n);

    // make some json
    SkDynamicMemoryWStream stream;
    SkJSONWriter writer(&stream, SkJSONWriter::Mode::kFast);

    SkM44 vm = fDebugCanvas->getCurrentMatrix();
    SkIRect clip = fDebugCanvas->getCurrentClip();

    writer.beginObject(); // root
    writer.appendName("ViewMatrix");
    DrawCommand::MakeJsonMatrix44(writer, vm);
    writer.appendName("ClipRect");
    DrawCommand::MakeJsonIRect(writer, clip);
    writer.endObject(); // root

    // TODO: Old code explicitly avoided the null terminator in the returned data. Important?
    writer.flush();
    return stream.detachAsData();
}

SkColor Request::getPixel(int x, int y) {
    SkBitmap bmp;
    bmp.allocPixels(this->getCanvas()->imageInfo().makeWH(1, 1));
    SkAssertResult(this->getCanvas()->readPixels(bmp, x, y));
    return bmp.getColor(0, 0);
}
