#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
/**
 * Size of the read buffer (to be allocated with @c malloc())
 */
#define READ_BUFFER_SIZE (4*1024*1024)
int main(int argc, char** argv)
{
    FILE* in     = NULL;    /* Input file */
    FILE* out    = NULL;    /* Output file */
    uint8_t* buf = NULL;    /* Read buffer */
    uint64_t bytes_to_copy = 0; /* How many bytes we are to copy */
    uint32_t id[3];             /* Nero footer */
    size_t read;            /* Number of bytes read */
    size_t to_read;         /* Number of bytes to read in the loop */
    size_t written;         /* Number of bytes written */
    int exit_code = EXIT_SUCCESS;   /* Exit code */
    if (3 != argc) {
        printf("Usage: nrg2iso nrgfile isofile\n");
        return EXIT_FAILURE;
    }
    in = fopen(argv[1], "rb");
    if (NULL == in) {
        printf("Failed to open file '%s' for reading\n", argv[1]);
        return EXIT_FAILURE;
    }
    out = fopen(argv[2], "wb");
    if (NULL == out) {
        fclose(in);
        printf("Failed to create file '%s'\n", argv[2]);
        return EXIT_FAILURE;
    }
    buf = malloc(READ_BUFFER_SIZE);
    if (NULL == buf) {
        fclose(in);
        fclose(out);
        printf("Failed to allocate %lu bytes of memory\n", (unsigned long)READ_BUFFER_SIZE);
        return EXIT_FAILURE;
    }
    fseek(in, -sizeof(id), SEEK_END);
    read = fread(&id, 1, sizeof(id), in);
    if (read != sizeof(id)) {
        fclose(in);
        fclose(out);
        printf("Read error (read: %u, needed: %u)\n", read, sizeof(id));
        return EXIT_FAILURE;
    }
    if (0x3552454Eul == id[0]) {    /* Nero v2 footer */
        id[1] = ((id[1] & 0x000000FF) << 24) |
                ((id[1] & 0x0000FF00) << 8) |
                ((id[1] & 0x00FF0000) >> 8) |
                ((id[1] & 0xFF000000) >> 24);
        id[2] = ((id[2] & 0x000000FF) << 24) |
                ((id[2] & 0x0000FF00) << 8) |
                ((id[2] & 0x00FF0000) >> 8) |
                ((id[2] & 0xFF000000) >> 24);
        bytes_to_copy = id[2] | ((uint64_t)(id[1]) << 32);
    }
    else if (0x4F52454E == id[1]) { /* Nero v1 footer */
        bytes_to_copy = id[2];
        bytes_to_copy = ((bytes_to_copy & 0x000000FF) << 24) |
                        ((bytes_to_copy & 0x0000FF00) << 8) |
                        ((bytes_to_copy & 0x00FF0000) >> 8) |
                        ((bytes_to_copy & 0xFF000000) >> 24);
    }
    else {
        fclose(in);
        fclose(out);
        free(buf);
        printf("Not a Nero image\n");
        return EXIT_FAILURE;
    }
    bytes_to_copy -= 512*600;
    fseek(in, 512*600, SEEK_SET);
    while (bytes_to_copy > 0) {
        to_read = (bytes_to_copy < READ_BUFFER_SIZE) ? bytes_to_copy : READ_BUFFER_SIZE;
        read    = fread(buf, 1, to_read, in);
        if (0 == read) {
            exit_code = EXIT_FAILURE;
            printf("\n\nPhysical EOF before logical EOF on '%s'\n", argv[1]);
            break;
        }
        written = fwrite(buf, 1, read, out);
        if (written != read) {
            exit_code = EXIT_FAILURE;
            printf("\n\nWrite error\n");
            break;
        }
        bytes_to_copy -= read;
        printf(".");
    }
    if (EXIT_SUCCESS == exit_code) {
        printf("\n\nSuccess!\n");
    }
    fclose(in);
    fclose(out);
    free(buf);
    return exit_code;
}