#include <iostream>
#include <vector>

// Generator polynomial GM(x) = x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1
const uint32_t generator = 0x04C11DB7;

// Compute CRC32 over a buffer of data
uint32_t compute_crc32(std::vector<uint8_t>& data) {
    uint32_t crc = 0x00000001; // Initial remainder
    for(auto& byte : data) {
        crc ^= static_cast<uint32_t>(byte) << 24;
        for (unsigned i = 0; i < 8; ++i) {
            if (crc & 0x80000000) {
                crc = (crc << 1) ^ generator;
            } else {
                crc <<= 1;
            }
        }
    }
    return crc;
}

int main() {
    // Test with some data
    std::vector<uint8_t> data = { 214,121,0,98,98,0,3,191,0,7,0,0,0,0,0,0,0,0,0,0 };
    uint32_t crc = compute_crc32(data);
    std::cout << "CRC32: " << std::dec << (int)crc << std::endl;
    
     uint8_t crcOctets[4];
    crcOctets[0] = (crc >> 24) & 0xFF;
    crcOctets[1] = (crc >> 16) & 0xFF;
    crcOctets[2] = (crc >> 8) & 0xFF;
    crcOctets[3] = (crc >> 0) & 0xFF;///////////

    // Print the CRC octets
    for (int i = 0; i < 4; i++) {
        std::cout <<"CRC Octet"<<i<<" "<<(int)crcOctets[i]<<std::endl;
    }
    
    
    return 0;
}