/*

 * Copyright 2019 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#include "tools/SkSharingProc.h"

#include "include/codec/SkPngDecoder.h"

#include "include/core/SkBitmap.h"

#include "include/core/SkData.h"

#include "include/core/SkImage.h"

#include "include/core/SkPicture.h"

#include "include/core/SkSerialProcs.h"

#include "include/core/SkStream.h"

#include "include/encode/SkPngEncoder.h"

namespace {

    sk_sp<SkData> collectNonTextureImagesProc(SkImage* img, void* ctx) {

        SkSharingSerialContext* context = reinterpret_cast<SkSharingSerialContext*>(ctx);

        uint32_t originalId = img->uniqueID();

        sk_sp<SkImage>* imageInMap = context->fNonTexMap.find(originalId);

        if (!imageInMap) {

            context->fNonTexMap[originalId] = img->makeNonTextureImage();

        }

        // This function implements a proc that is more generally for serialization, but

        // we really only want to build our map. The output of this function is ignored.

        return SkData::MakeEmpty();

    }

}

void SkSharingSerialContext::collectNonTextureImagesFromPicture(

    const SkPicture* pic, SkSharingSerialContext* sharingCtx) {

    SkSerialProcs tempProc;

    tempProc.fImageCtx = sharingCtx;

    tempProc.fImageProc = collectNonTextureImagesProc;

    SkNullWStream ns;

    pic->serialize(&ns, &tempProc);

}

sk_sp<SkData> SkSharingSerialContext::serializeImage(SkImage* img, void* ctx) {

    SkSharingSerialContext* context = reinterpret_cast<SkSharingSerialContext*>(ctx);

    uint32_t id = img->uniqueID(); // get this process's id for the image. these are not hashes.

    // find out if we have already serialized this, and if so, what its in-file id is.

    int* fid = context->fImageMap.find(id);

    if (!fid) {

        // When not present, add its id to the map and return its usual serialized form.

        context->fImageMap[id] = context->fImageMap.count(); // Next in-file id

        // encode the image or it's non-texture replacement if one was collected

        sk_sp<SkImage>* replacementImage = context->fNonTexMap.find(id);

        if (replacementImage) {

            img = replacementImage->get();

        }

        return SkPngEncoder::Encode(nullptr, img, {});

    }

    // if present, return only the in-file id we registered the first time we serialized it.

    return SkData::MakeWithCopy(fid, sizeof(*fid));

}

sk_sp<SkImage> SkSharingDeserialContext::deserializeImage(

  const void* data, size_t length, void* ctx) {

    if (!data || !length || !ctx) {

        SkDebugf("SkSharingDeserialContext::deserializeImage arguments invalid %p %zu %p.\n",

            data, length, ctx);

        // Return something so the rest of the debugger can proceed.

        SkBitmap bm;

        bm.allocPixels(SkImageInfo::MakeN32Premul(1, 1));

        return bm.asImage();

    }

    SkSharingDeserialContext* context = reinterpret_cast<SkSharingDeserialContext*>(ctx);

    uint32_t fid;

    // If the data is an image fid, look up an already deserialized image from our map

    if (length == sizeof(fid)) {

        memcpy(&fid, data, sizeof(fid));

        if (fid >= context->fImages.size()) {

            SkDebugf("Cannot deserialize using id, We do not have the data for image %u.\n", fid);

            return nullptr;

        }

        return context->fImages[fid];

    }

    // Otherwise, the data is an image, deserialise it, store it in our map at its fid.

    // TODO(nifong): make DeserialProcs accept sk_sp<SkData> so we don't have to copy this.

    sk_sp<SkData> dataView = SkData::MakeWithCopy(data, length);

    auto codec = SkPngDecoder::Decode(std::move(dataView), nullptr);

    if (!codec) {

        SkDebugf("Cannot deserialize image - might not be a PNG.\n");

        return nullptr;

    }

    SkImageInfo info = codec->getInfo().makeAlphaType(kPremul_SkAlphaType);

    auto [image, result] = codec->getImage(info);

    if (result != SkCodec::Result::kSuccess) {

        SkDebugf("Error decoding image %d.\n", result);

        // Might have partially decoded.

    }

    context->fImages.push_back(image);

    return image;

}