/*
 * Copyright (c) 2021 - 2022 Samsung Electronics Co., Ltd. All rights reserved.

 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include <memory.h>

#ifdef _WIN32
    #include <malloc.h>
#elif defined(__FreeBSD__)
    #include <stdlib.h>
#else
    #include <alloca.h>
#endif

#include "tvgTvgCommon.h"


/************************************************************************/
/* Internal Class Implementation                                        */
/************************************************************************/

struct TvgBinBlock
{
    TvgBinTag type;
    TvgBinCounter length;
    const char* data;
    const char* end;
};

static Paint* _parsePaint(TvgBinBlock baseBlock);


static TvgBinBlock _readBlock(const char *ptr)
{
    TvgBinBlock block;
    block.type = *ptr;
    READ_UI32(&block.length, ptr + SIZE(TvgBinTag));
    block.data = ptr + SIZE(TvgBinTag) + SIZE(TvgBinCounter);
    block.end = block.data + block.length;
    return block;
}


static bool _parseCmpTarget(const char *ptr, const char *end, Paint *paint)
{
    auto block = _readBlock(ptr);
    if (block.end > end) return false;

    if (block.type != TVG_TAG_PAINT_CMP_METHOD) return false;
    if (block.length != SIZE(TvgBinFlag)) return false;

    auto cmpMethod = static_cast<CompositeMethod>(*block.data);

    ptr = block.end;

    auto cmpBlock = _readBlock(ptr);
    if (cmpBlock.end > end) return false;

    paint->composite(unique_ptr<Paint>(_parsePaint(cmpBlock)), cmpMethod);

    return true;
}


static bool _parsePaintProperty(TvgBinBlock block, Paint *paint)
{
    switch (block.type) {
        case TVG_TAG_PAINT_OPACITY: {
            if (block.length != SIZE(uint8_t)) return false;
            paint->opacity(*block.data);
            return true;
        }
        case TVG_TAG_PAINT_TRANSFORM: {
            if (block.length != SIZE(Matrix)) return false;
            Matrix matrix;
            memcpy(&matrix, block.data, SIZE(Matrix));
            paint->transform(matrix);
            return true;
        }
        case TVG_TAG_PAINT_CMP_TARGET: {
            if (block.length < SIZE(TvgBinTag) + SIZE(TvgBinCounter)) return false;
            return _parseCmpTarget(block.data, block.end, paint);
        }
    }
    return false;
}


static bool _parseScene(TvgBinBlock block, Paint *paint)
{
    auto scene = static_cast<Scene*>(paint);

    //Case1: scene reserve count
    if (block.type == TVG_TAG_SCENE_RESERVEDCNT) {
        if (block.length != SIZE(uint32_t)) return false;
        uint32_t reservedCnt;
        READ_UI32(&reservedCnt, block.data);
        scene->reserve(reservedCnt);
        return true;
    }

    //Case2: Base Paint Properties
    if (_parsePaintProperty(block, scene)) return true;

    //Case3: A Child paint
    if (auto paint = _parsePaint(block)) {
        scene->push(unique_ptr<Paint>(paint));
        return true;
    }

    return false;
}


static bool _parseShapePath(const char *ptr, const char *end, Shape *shape)
{
    uint32_t cmdCnt, ptsCnt;

    READ_UI32(&cmdCnt, ptr);
    ptr += SIZE(cmdCnt);

    READ_UI32(&ptsCnt, ptr);
    ptr += SIZE(ptsCnt);

    auto cmds = (TvgBinFlag*) ptr;
    ptr += SIZE(TvgBinFlag) * cmdCnt;

    auto pts = (Point*) ptr;
    ptr += SIZE(Point) * ptsCnt;

    if (ptr > end) return false;

    /* Recover to PathCommand(4 bytes) from TvgBinFlag(1 byte) */
    PathCommand* inCmds = (PathCommand*)alloca(sizeof(PathCommand) * cmdCnt);
    for (uint32_t i = 0; i < cmdCnt; ++i) {
        inCmds[i] = static_cast<PathCommand>(cmds[i]);
    }

    shape->appendPath(inCmds, cmdCnt, pts, ptsCnt);

    return true;
}


static unique_ptr<Fill> _parseShapeFill(const char *ptr, const char *end)
{
    unique_ptr<Fill> fillGrad;

    while (ptr < end) {
        auto block = _readBlock(ptr);
        if (block.end > end) return nullptr;

        switch (block.type) {
            case TVG_TAG_FILL_RADIAL_GRADIENT: {
                if (block.length != 3 * SIZE(float)) return nullptr;

                auto ptr = block.data;
                float x, y, radius;

                READ_FLOAT(&x, ptr);
                ptr += SIZE(float);
                READ_FLOAT(&y, ptr);
                ptr += SIZE(float);
                READ_FLOAT(&radius, ptr);

                auto fillGradRadial = RadialGradient::gen();
                fillGradRadial->radial(x, y, radius);
                fillGrad = move(fillGradRadial);
                break;
            }
            case TVG_TAG_FILL_LINEAR_GRADIENT: {
                if (block.length != 4 * SIZE(float)) return nullptr;

                auto ptr = block.data;
                float x1, y1, x2, y2;

                READ_FLOAT(&x1, ptr);
                ptr += SIZE(float);
                READ_FLOAT(&y1, ptr);
                ptr += SIZE(float);
                READ_FLOAT(&x2, ptr);
                ptr += SIZE(float);
                READ_FLOAT(&y2, ptr);

                auto fillGradLinear = LinearGradient::gen();
                fillGradLinear->linear(x1, y1, x2, y2);
                fillGrad = move(fillGradLinear);
                break;
            }
            case TVG_TAG_FILL_FILLSPREAD: {
                if (!fillGrad) return nullptr;
                if (block.length != SIZE(TvgBinFlag)) return nullptr;
                fillGrad->spread((FillSpread) *block.data);
                break;
            }
            case TVG_TAG_FILL_COLORSTOPS: {
                if (!fillGrad) return nullptr;
                if (block.length == 0 || block.length & 0x07) return nullptr;
                uint32_t stopsCnt = block.length >> 3; // 8 bytes per ColorStop
                if (stopsCnt > 1023) return nullptr;
                Fill::ColorStop* stops = (Fill::ColorStop*)alloca(sizeof(Fill::ColorStop) * stopsCnt);
                auto p = block.data;
                for (uint32_t i = 0; i < stopsCnt; i++, p += 8) {
                    READ_FLOAT(&stops[i].offset, p);
                    stops[i].r = p[4];
                    stops[i].g = p[5];
                    stops[i].b = p[6];
                    stops[i].a = p[7];
                }
                fillGrad->colorStops(stops, stopsCnt);
                break;
            }
            case TVG_TAG_FILL_TRANSFORM: {
                if (!fillGrad || block.length != SIZE(Matrix)) return nullptr;
                Matrix gradTransform;
                memcpy(&gradTransform, block.data, SIZE(Matrix));
                fillGrad->transform(gradTransform);
                break;
            }
            default: {
                TVGLOG("TVG", "Unsupported tag %d (0x%x) used as one of the fill properties, %d bytes skipped", block.type, block.type, block.length);
                break;
            }
        }
        ptr = block.end;
    }
    return fillGrad;
}


static bool _parseShapeStrokeDashPattern(const char *ptr, const char *end, Shape *shape)
{
    uint32_t dashPatternCnt;
    READ_UI32(&dashPatternCnt, ptr);
    ptr += SIZE(uint32_t);
    if (dashPatternCnt > 0) {
        float* dashPattern = static_cast<float*>(malloc(sizeof(float) * dashPatternCnt));
        if (!dashPattern) return false;
        memcpy(dashPattern, ptr, sizeof(float) * dashPatternCnt);
        ptr += SIZE(float) * dashPatternCnt;

        if (ptr > end) {
            free(dashPattern);
            return false;
        }

        shape->stroke(dashPattern, dashPatternCnt);
        free(dashPattern);
    }
    return true;
}


static bool _parseShapeStroke(const char *ptr, const char *end, Shape *shape)
{
    while (ptr < end) {
        auto block = _readBlock(ptr);
        if (block.end > end) return false;

        switch (block.type) {
            case TVG_TAG_SHAPE_STROKE_CAP: {
                if (block.length != SIZE(TvgBinFlag)) return false;
                shape->stroke((StrokeCap) *block.data);
                break;
            }
            case TVG_TAG_SHAPE_STROKE_JOIN: {
                if (block.length != SIZE(TvgBinFlag)) return false;
                shape->stroke((StrokeJoin) *block.data);
                break;
            }
            case TVG_TAG_SHAPE_STROKE_WIDTH: {
                if (block.length != SIZE(float)) return false;
                float width;
                READ_FLOAT(&width, block.data);
                shape->stroke(width);
                break;
            }
            case TVG_TAG_SHAPE_STROKE_COLOR: {
                if (block.length != 4) return false;
                shape->stroke(block.data[0], block.data[1], block.data[2], block.data[3]);
                break;
            }
            case TVG_TAG_SHAPE_STROKE_FILL: {
                auto fill = _parseShapeFill(block.data, block.end);
                if (!fill) return false;
                shape->stroke(move(move(fill)));
                break;
            }
            case TVG_TAG_SHAPE_STROKE_DASHPTRN: {
                if (!_parseShapeStrokeDashPattern(block.data, block.end, shape)) return false;
                break;
            }
            default: {
                TVGLOG("TVG", "Unsupported tag %d (0x%x) used as one of stroke properties, %d bytes skipped", block.type, block.type, block.length);
                break;
            }
        }
        ptr = block.end;
    }
    return true;
}


static bool _parseShape(TvgBinBlock block, Paint* paint)
{
    auto shape = static_cast<Shape*>(paint);

    //Case1: Shape specific properties
    switch (block.type) {
        case TVG_TAG_SHAPE_PATH: {
            return _parseShapePath(block.data, block.end, shape);
        }
        case TVG_TAG_SHAPE_STROKE: {
            return _parseShapeStroke(block.data, block.end, shape);
        }
        case TVG_TAG_SHAPE_FILL: {
            auto fill = _parseShapeFill(block.data, block.end);
            if (!fill) return false;
            shape->fill(move(fill));
            return true;
        }
        case TVG_TAG_SHAPE_COLOR: {
            if (block.length != 4) return false;
            shape->fill(block.data[0], block.data[1], block.data[2], block.data[3]);
            return true;
        }
        case TVG_TAG_SHAPE_FILLRULE: {
            if (block.length != SIZE(TvgBinFlag)) return false;
            shape->fill((FillRule)*block.data);
            return true;
        }
    }

    //Case2: Base Paint Properties
    return _parsePaintProperty(block, shape);
}


static bool _parsePicture(TvgBinBlock block, Paint* paint)
{
    auto picture = static_cast<Picture*>(paint);

    //Case1: Image Picture
    if (block.type == TVG_TAG_PICTURE_RAW_IMAGE) {
        if (block.length < 2 * SIZE(uint32_t)) return false;

        auto ptr = block.data;
        uint32_t w, h;

        READ_UI32(&w, ptr);
        ptr += SIZE(uint32_t);
        READ_UI32(&h, ptr);
        ptr += SIZE(uint32_t);

        auto size = w * h * SIZE(uint32_t);
        if (block.length != 2 * SIZE(uint32_t) + size) return false;

        picture->load((uint32_t*) ptr, w, h, true);
        return true;
    }

    //Case2: Base Paint Properties
    if (_parsePaintProperty(block, picture)) return true;

    //Vector Picture won't be requested since Saver replaces it with the Scene
    return false;
}


static Paint* _parsePaint(TvgBinBlock baseBlock)
{
    bool (*parser)(TvgBinBlock, Paint*);
    Paint *paint;

    //1. Decide the type of paint.
    switch (baseBlock.type) {
        case TVG_TAG_CLASS_SCENE: {
            paint = Scene::gen().release();
            parser = _parseScene;
            break;
        }
        case TVG_TAG_CLASS_SHAPE: {
            paint = Shape::gen().release();
            parser = _parseShape;
            break;
        }
        case TVG_TAG_CLASS_PICTURE: {
            paint = Picture::gen().release();
            parser = _parsePicture;
            break;
        }
        default: {
            TVGERR("TVG", "Invalid Paint Type %d (0x%x)", baseBlock.type, baseBlock.type);
            return nullptr;
        }
    }

    auto ptr = baseBlock.data;

    //2. Read Subsquent properties of the current paint.
    while (ptr < baseBlock.end) {
        auto block = _readBlock(ptr);
        if (block.end > baseBlock.end) return paint;
        if (!parser(block, paint)) {
            TVGERR("TVG", "Encountered the wrong paint properties... Paint Class %d (0x%x)", baseBlock.type, baseBlock.type);
            return paint;
        }
        ptr = block.end;
    }
    return paint;
}



/************************************************************************/
/* External Class Implementation                                        */
/************************************************************************/

unique_ptr<Scene> TvgBinInterpreter::run(const char *ptr, const char* end)
{
    auto scene = Scene::gen();
    if (!scene) return nullptr;

    while (ptr < end) {
        auto block = _readBlock(ptr);
        if (block.end > end) {
            TVGERR("TVG", "Corrupted tvg file.");
            return nullptr;
        }
        scene->push(unique_ptr<Paint>(_parsePaint(block)));
        ptr = block.end;
    }

    return scene;
}