#include <stdio.h>
#include <stdlib.h>
#include "crc_util.h"

const long png_signature[8] = { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a };


int check_header_length(unsigned char *addr, long offset) {
        unsigned int res = 0;
        for( int i = 0; i < 4; i++ ) {
                res |= addr[offset+i];
                if (i < 3) {
                        res <<= 8;
                }
        }
        return res;
}

int check_file_header(char *addr) {
        int signature_match = 0;
        for( int i = 0; i < 8; i++ ) {
                if (addr[i] != png_signature[i]) {
                        signature_match = 1;
                }
        }
        printf("Sig Match: %d\n", signature_match);
        return signature_match;

}

int create_cc_file(unsigned char *addr, unsigned long file_length) {
        FILE *fp;
        fp = fopen("png2.png", "w");

        if(fp == NULL) {
                return EXIT_FAILURE;
        }

        for(int i = 0; i < file_length; i++){
                fputc(addr[i], fp);
        }
        fclose(fp);
}