/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <ultrahdr/jpegdecoderhelper.h>

#include <utils/Log.h>

#include <errno.h>
#include <setjmp.h>
#include <string>

using namespace std;

namespace android::ultrahdr {

#define ALIGNM(x, m)  ((((x) + ((m) - 1)) / (m)) * (m))

const uint32_t kAPP0Marker = JPEG_APP0;      // JFIF
const uint32_t kAPP1Marker = JPEG_APP0 + 1;  // EXIF, XMP
const uint32_t kAPP2Marker = JPEG_APP0 + 2;  // ICC

const std::string kXmpNameSpace = "http://ns.adobe.com/xap/1.0/";
const std::string kExifIdCode = "Exif";
constexpr uint32_t kICCMarkerHeaderSize = 14;
constexpr uint8_t kICCSig[] = {
        'I', 'C', 'C', '_', 'P', 'R', 'O', 'F', 'I', 'L', 'E', '\0',
};

struct jpegr_source_mgr : jpeg_source_mgr {
    jpegr_source_mgr(const uint8_t* ptr, int len);
    ~jpegr_source_mgr();

    const uint8_t* mBufferPtr;
    size_t mBufferLength;
};

struct jpegrerror_mgr {
    struct jpeg_error_mgr pub;
    jmp_buf setjmp_buffer;
};

static void jpegr_init_source(j_decompress_ptr cinfo) {
    jpegr_source_mgr* src = static_cast<jpegr_source_mgr*>(cinfo->src);
    src->next_input_byte = static_cast<const JOCTET*>(src->mBufferPtr);
    src->bytes_in_buffer = src->mBufferLength;
}

static boolean jpegr_fill_input_buffer(j_decompress_ptr /* cinfo */) {
    ALOGE("%s : should not get here", __func__);
    return FALSE;
}

static void jpegr_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
    jpegr_source_mgr* src = static_cast<jpegr_source_mgr*>(cinfo->src);

    if (num_bytes > static_cast<long>(src->bytes_in_buffer)) {
        ALOGE("jpegr_skip_input_data - num_bytes > (long)src->bytes_in_buffer");
    } else {
        src->next_input_byte += num_bytes;
        src->bytes_in_buffer -= num_bytes;
    }
}

static void jpegr_term_source(j_decompress_ptr /*cinfo*/) {}

jpegr_source_mgr::jpegr_source_mgr(const uint8_t* ptr, int len) :
        mBufferPtr(ptr), mBufferLength(len) {
    init_source = jpegr_init_source;
    fill_input_buffer = jpegr_fill_input_buffer;
    skip_input_data = jpegr_skip_input_data;
    resync_to_restart = jpeg_resync_to_restart;
    term_source = jpegr_term_source;
}

jpegr_source_mgr::~jpegr_source_mgr() {}

static void jpegrerror_exit(j_common_ptr cinfo) {
    jpegrerror_mgr* err = reinterpret_cast<jpegrerror_mgr*>(cinfo->err);
    longjmp(err->setjmp_buffer, 1);
}

JpegDecoderHelper::JpegDecoderHelper() {
}

JpegDecoderHelper::~JpegDecoderHelper() {
}

bool JpegDecoderHelper::decompressImage(const void* image, int length, bool decodeToRGBA) {
    if (image == nullptr || length <= 0) {
        ALOGE("Image size can not be handled: %d", length);
        return false;
    }

    mResultBuffer.clear();
    mXMPBuffer.clear();
    if (!decode(image, length, decodeToRGBA)) {
        return false;
    }

    return true;
}

void* JpegDecoderHelper::getDecompressedImagePtr() {
    return mResultBuffer.data();
}

size_t JpegDecoderHelper::getDecompressedImageSize() {
    return mResultBuffer.size();
}

void* JpegDecoderHelper::getXMPPtr() {
    return mXMPBuffer.data();
}

size_t JpegDecoderHelper::getXMPSize() {
    return mXMPBuffer.size();
}

void* JpegDecoderHelper::getEXIFPtr() {
    return mEXIFBuffer.data();
}

size_t JpegDecoderHelper::getEXIFSize() {
    return mEXIFBuffer.size();
}

void* JpegDecoderHelper::getICCPtr() {
    return mICCBuffer.data();
}

size_t JpegDecoderHelper::getICCSize() {
    return mICCBuffer.size();
}

size_t JpegDecoderHelper::getDecompressedImageWidth() {
    return mWidth;
}

size_t JpegDecoderHelper::getDecompressedImageHeight() {
    return mHeight;
}

bool JpegDecoderHelper::decode(const void* image, int length, bool decodeToRGBA) {
    jpeg_decompress_struct cinfo;
    jpegr_source_mgr mgr(static_cast<const uint8_t*>(image), length);
    jpegrerror_mgr myerr;
    bool status = true;

    cinfo.err = jpeg_std_error(&myerr.pub);
    myerr.pub.error_exit = jpegrerror_exit;

    if (setjmp(myerr.setjmp_buffer)) {
        jpeg_destroy_decompress(&cinfo);
        return false;
    }
    jpeg_create_decompress(&cinfo);

    jpeg_save_markers(&cinfo, kAPP0Marker, 0xFFFF);
    jpeg_save_markers(&cinfo, kAPP1Marker, 0xFFFF);
    jpeg_save_markers(&cinfo, kAPP2Marker, 0xFFFF);

    cinfo.src = &mgr;
    jpeg_read_header(&cinfo, TRUE);

    // Save XMP data, EXIF data, and ICC data.
    // Here we only handle the first XMP / EXIF / ICC package.
    // We assume that all packages are starting with two bytes marker (eg FF E1 for EXIF package),
    // two bytes of package length which is stored in marker->original_length, and the real data
    // which is stored in marker->data.
    bool exifAppears = false;
    bool xmpAppears = false;
    bool iccAppears = false;
    for (jpeg_marker_struct* marker = cinfo.marker_list;
         marker && !(exifAppears && xmpAppears && iccAppears);
         marker = marker->next) {

        if (marker->marker != kAPP1Marker && marker->marker != kAPP2Marker) {
            continue;
        }
        const unsigned int len = marker->data_length;
        if (!xmpAppears &&
            len > kXmpNameSpace.size() &&
            !strncmp(reinterpret_cast<const char*>(marker->data),
                     kXmpNameSpace.c_str(),
                     kXmpNameSpace.size())) {
            mXMPBuffer.resize(len+1, 0);
            memcpy(static_cast<void*>(mXMPBuffer.data()), marker->data, len);
            xmpAppears = true;
        } else if (!exifAppears &&
                   len > kExifIdCode.size() &&
                   !strncmp(reinterpret_cast<const char*>(marker->data),
                            kExifIdCode.c_str(),
                            kExifIdCode.size())) {
            mEXIFBuffer.resize(len, 0);
            memcpy(static_cast<void*>(mEXIFBuffer.data()), marker->data, len);
            exifAppears = true;
        } else if (!iccAppears &&
                   len > sizeof(kICCSig) &&
                   !memcmp(marker->data, kICCSig, sizeof(kICCSig))) {
            mICCBuffer.resize(len, 0);
            memcpy(static_cast<void*>(mICCBuffer.data()), marker->data, len);
            iccAppears = true;
        }
    }

    if (cinfo.image_width > kMaxWidth || cinfo.image_height > kMaxHeight) {
        // constraint on max width and max height is only due to alloc constraints
        // tune these values basing on the target device
        status = false;
        goto CleanUp;
    }

    mWidth = cinfo.image_width;
    mHeight = cinfo.image_height;

    if (decodeToRGBA) {
        if (cinfo.jpeg_color_space == JCS_GRAYSCALE) {
            // We don't intend to support decoding grayscale to RGBA
            status = false;
            ALOGE("%s: decoding grayscale to RGBA is unsupported", __func__);
            goto CleanUp;
        }
        // 4 bytes per pixel
        mResultBuffer.resize(cinfo.image_width * cinfo.image_height * 4);
        cinfo.out_color_space = JCS_EXT_RGBA;
    } else {
        if (cinfo.jpeg_color_space == JCS_YCbCr) {
            if (cinfo.comp_info[0].h_samp_factor != 2 ||
                cinfo.comp_info[1].h_samp_factor != 1 ||
                cinfo.comp_info[2].h_samp_factor != 1 ||
                cinfo.comp_info[0].v_samp_factor != 2 ||
                cinfo.comp_info[1].v_samp_factor != 1 ||
                cinfo.comp_info[2].v_samp_factor != 1) {
                status = false;
                ALOGE("%s: decoding to YUV only supports 4:2:0 subsampling", __func__);
                goto CleanUp;
            }
            mResultBuffer.resize(cinfo.image_width * cinfo.image_height * 3 / 2, 0);
        } else if (cinfo.jpeg_color_space == JCS_GRAYSCALE) {
            mResultBuffer.resize(cinfo.image_width * cinfo.image_height, 0);
        }
        cinfo.out_color_space = cinfo.jpeg_color_space;
        cinfo.raw_data_out = TRUE;
    }

    cinfo.dct_method = JDCT_IFAST;

    jpeg_start_decompress(&cinfo);

    if (!decompress(&cinfo, static_cast<const uint8_t*>(mResultBuffer.data()),
            cinfo.jpeg_color_space == JCS_GRAYSCALE)) {
        status = false;
        goto CleanUp;
    }

CleanUp:
    jpeg_finish_decompress(&cinfo);
    jpeg_destroy_decompress(&cinfo);

    return status;
}

bool JpegDecoderHelper::decompress(jpeg_decompress_struct* cinfo, const uint8_t* dest,
        bool isSingleChannel) {
    if (isSingleChannel) {
        return decompressSingleChannel(cinfo, dest);
    }
    if (cinfo->out_color_space == JCS_EXT_RGBA)
        return decompressRGBA(cinfo, dest);
    else
        return decompressYUV(cinfo, dest);
}

bool JpegDecoderHelper::getCompressedImageParameters(const void* image, int length,
                              size_t *pWidth, size_t *pHeight,
                              std::vector<uint8_t> *iccData , std::vector<uint8_t> *exifData) {
    jpeg_decompress_struct cinfo;
    jpegr_source_mgr mgr(static_cast<const uint8_t*>(image), length);
    jpegrerror_mgr myerr;
    cinfo.err = jpeg_std_error(&myerr.pub);
    myerr.pub.error_exit = jpegrerror_exit;

    if (setjmp(myerr.setjmp_buffer)) {
        jpeg_destroy_decompress(&cinfo);
        return false;
    }
    jpeg_create_decompress(&cinfo);

    jpeg_save_markers(&cinfo, kAPP1Marker, 0xFFFF);
    jpeg_save_markers(&cinfo, kAPP2Marker, 0xFFFF);

    cinfo.src = &mgr;
    if (jpeg_read_header(&cinfo, TRUE) != JPEG_HEADER_OK) {
        jpeg_destroy_decompress(&cinfo);
        return false;
    }

    if (pWidth != nullptr) {
        *pWidth = cinfo.image_width;
    }
    if (pHeight != nullptr) {
        *pHeight = cinfo.image_height;
    }

    if (iccData != nullptr) {
        for (jpeg_marker_struct* marker = cinfo.marker_list; marker;
             marker = marker->next) {
            if (marker->marker != kAPP2Marker) {
                continue;
            }
            if (marker->data_length <= kICCMarkerHeaderSize ||
                memcmp(marker->data, kICCSig, sizeof(kICCSig)) != 0) {
                continue;
            }

            iccData->insert(iccData->end(), marker->data, marker->data + marker->data_length);
        }
    }

    if (exifData != nullptr) {
        bool exifAppears = false;
        for (jpeg_marker_struct* marker = cinfo.marker_list; marker && !exifAppears;
             marker = marker->next) {
            if (marker->marker != kAPP1Marker) {
                continue;
            }

            const unsigned int len = marker->data_length;
            if (len >= kExifIdCode.size() &&
                !strncmp(reinterpret_cast<const char*>(marker->data), kExifIdCode.c_str(),
                         kExifIdCode.size())) {
                exifData->resize(len, 0);
                memcpy(static_cast<void*>(exifData->data()), marker->data, len);
                exifAppears = true;
            }
        }
    }

    jpeg_destroy_decompress(&cinfo);
    return true;
}

bool JpegDecoderHelper::decompressRGBA(jpeg_decompress_struct* cinfo, const uint8_t* dest) {
    JSAMPLE* decodeDst = (JSAMPLE*) dest;
    uint32_t lines = 0;
    // TODO: use batches for more effectiveness
    while (lines < cinfo->image_height) {
        uint32_t ret = jpeg_read_scanlines(cinfo, &decodeDst, 1);
        if (ret == 0) {
            break;
        }
        decodeDst += cinfo->image_width * 4;
        lines++;
    }
    return lines == cinfo->image_height;
}

bool JpegDecoderHelper::decompressYUV(jpeg_decompress_struct* cinfo, const uint8_t* dest) {
    JSAMPROW y[kCompressBatchSize];
    JSAMPROW cb[kCompressBatchSize / 2];
    JSAMPROW cr[kCompressBatchSize / 2];
    JSAMPARRAY planes[3] {y, cb, cr};

    size_t y_plane_size = cinfo->image_width * cinfo->image_height;
    size_t uv_plane_size = y_plane_size / 4;
    uint8_t* y_plane = const_cast<uint8_t*>(dest);
    uint8_t* u_plane = const_cast<uint8_t*>(dest + y_plane_size);
    uint8_t* v_plane = const_cast<uint8_t*>(dest + y_plane_size + uv_plane_size);
    std::unique_ptr<uint8_t[]> empty = std::make_unique<uint8_t[]>(cinfo->image_width);
    memset(empty.get(), 0, cinfo->image_width);

    const int aligned_width = ALIGNM(cinfo->image_width, kCompressBatchSize);
    bool is_width_aligned = (aligned_width == cinfo->image_width);
    std::unique_ptr<uint8_t[]> buffer_intrm = nullptr;
    uint8_t* y_plane_intrm = nullptr;
    uint8_t* u_plane_intrm = nullptr;
    uint8_t* v_plane_intrm = nullptr;
    JSAMPROW y_intrm[kCompressBatchSize];
    JSAMPROW cb_intrm[kCompressBatchSize / 2];
    JSAMPROW cr_intrm[kCompressBatchSize / 2];
    JSAMPARRAY planes_intrm[3] {y_intrm, cb_intrm, cr_intrm};
    if (!is_width_aligned) {
        size_t mcu_row_size = aligned_width * kCompressBatchSize * 3 / 2;
        buffer_intrm = std::make_unique<uint8_t[]>(mcu_row_size);
        y_plane_intrm = buffer_intrm.get();
        u_plane_intrm = y_plane_intrm + (aligned_width * kCompressBatchSize);
        v_plane_intrm = u_plane_intrm + (aligned_width * kCompressBatchSize) / 4;
        for (int i = 0; i < kCompressBatchSize; ++i) {
            y_intrm[i] = y_plane_intrm + i * aligned_width;
        }
        for (int i = 0; i < kCompressBatchSize / 2; ++i) {
            int offset_intrm = i * (aligned_width / 2);
            cb_intrm[i] = u_plane_intrm + offset_intrm;
            cr_intrm[i] = v_plane_intrm + offset_intrm;
        }
    }

    while (cinfo->output_scanline < cinfo->image_height) {
        for (int i = 0; i < kCompressBatchSize; ++i) {
            size_t scanline = cinfo->output_scanline + i;
            if (scanline < cinfo->image_height) {
                y[i] = y_plane + scanline * cinfo->image_width;
            } else {
                y[i] = empty.get();
            }
        }
        // cb, cr only have half scanlines
        for (int i = 0; i < kCompressBatchSize / 2; ++i) {
            size_t scanline = cinfo->output_scanline / 2 + i;
            if (scanline < cinfo->image_height / 2) {
                int offset = scanline * (cinfo->image_width / 2);
                cb[i] = u_plane + offset;
                cr[i] = v_plane + offset;
            } else {
                cb[i] = cr[i] = empty.get();
            }
        }

        int processed = jpeg_read_raw_data(cinfo, is_width_aligned ? planes : planes_intrm,
                                           kCompressBatchSize);
        if (processed != kCompressBatchSize) {
            ALOGE("Number of processed lines does not equal input lines.");
            return false;
        }
        if (!is_width_aligned) {
            for (int i = 0; i < kCompressBatchSize; ++i) {
                memcpy(y[i], y_intrm[i], cinfo->image_width);
            }
            for (int i = 0; i < kCompressBatchSize / 2; ++i) {
                memcpy(cb[i], cb_intrm[i], cinfo->image_width / 2);
                memcpy(cr[i], cr_intrm[i], cinfo->image_width / 2);
            }
        }
    }
    return true;
}

bool JpegDecoderHelper::decompressSingleChannel(jpeg_decompress_struct* cinfo, const uint8_t* dest) {
    JSAMPROW y[kCompressBatchSize];
    JSAMPARRAY planes[1] {y};

    uint8_t* y_plane = const_cast<uint8_t*>(dest);
    std::unique_ptr<uint8_t[]> empty = std::make_unique<uint8_t[]>(cinfo->image_width);
    memset(empty.get(), 0, cinfo->image_width);

    int aligned_width = ALIGNM(cinfo->image_width, kCompressBatchSize);
    bool is_width_aligned = (aligned_width == cinfo->image_width);
    std::unique_ptr<uint8_t[]> buffer_intrm = nullptr;
    uint8_t* y_plane_intrm = nullptr;
    JSAMPROW y_intrm[kCompressBatchSize];
    JSAMPARRAY planes_intrm[1] {y_intrm};
    if (!is_width_aligned) {
        size_t mcu_row_size = aligned_width * kCompressBatchSize;
        buffer_intrm = std::make_unique<uint8_t[]>(mcu_row_size);
        y_plane_intrm = buffer_intrm.get();
        for (int i = 0; i < kCompressBatchSize; ++i) {
            y_intrm[i] = y_plane_intrm + i * aligned_width;
        }
    }

    while (cinfo->output_scanline < cinfo->image_height) {
        for (int i = 0; i < kCompressBatchSize; ++i) {
            size_t scanline = cinfo->output_scanline + i;
            if (scanline < cinfo->image_height) {
                y[i] = y_plane + scanline * cinfo->image_width;
            } else {
                y[i] = empty.get();
            }
        }

        int processed = jpeg_read_raw_data(cinfo, is_width_aligned ? planes : planes_intrm,
                                           kCompressBatchSize);
        if (processed != kCompressBatchSize / 2) {
            ALOGE("Number of processed lines does not equal input lines.");
            return false;
        }
        if (!is_width_aligned) {
            for (int i = 0; i < kCompressBatchSize; ++i) {
                memcpy(y[i], y_intrm[i], cinfo->image_width);
            }
        }
    }
    return true;
}

} // namespace ultrahdr