#include <iostream>
#include <vector>
#include <fstream>


const int rows = 8;
const int columns = 16;

const int H[rows][columns] = {
        {0,1,1,1,1,1,1,1, 1,0,0,0,0,0,0,0},
        {1,0,0,0,1,1,1,1, 0,1,0,0,0,0,0,0},
        {0,0,0,1,0,1,1,1, 0,0,1,0,0,0,0,0},
        {1,0,1,1,1,0,1,1, 0,0,0,1,0,0,0,0},
        {0,1,1,0,0,0,1,1, 0,0,0,0,1,0,0,0},
        {1,1,0,1,1,1,0,1, 0,0,0,0,0,1,0,0},
        {1,1,1,0,0,1,0,1, 0,0,0,0,0,0,1,0},
        {0,0,1,0,1,1,1,0, 0,0,0,0,0,0,0,1}
};

const int G[rows][columns] = {
        {1,0,0,0,0,0,0,0, 0,1,0,1,0,1,1,0},
        {0,1,0,0,0,0,0,0, 1,0,0,0,1,1,1,0},
        {0,0,1,0,0,0,0,0, 1,0,0,1,1,0,1,1},
        {0,0,0,1,0,0,0,0, 1,0,1,1,0,1,0,0},
        {0,0,0,0,1,0,0,0, 1,1,0,1,0,1,0,1},
        {0,0,0,0,0,1,0,0, 1,1,1,0,0,1,1,1},
        {0,0,0,0,0,0,1,0, 1,1,1,1,1,0,0,1},
        {0,0,0,0,0,0,0,1, 1,1,1,1,1,1,1,0}
};

std::vector<int> Generate(const int G[8][16],std::vector<int> msg){
    std::vector<int> code = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
    for(int i = 0; i < columns; i++)
    {
        for ( int j = 0 ; j < rows ; j ++ )
        {
            code[i] += G[j][i] * msg[j];
        }
        code[i] %= 2;
    }
    return  code;
}

std::vector<int> Check(std::vector<int> code){
    std::vector<int> result = {0,0,0,0,0,0,0,0};
    for(int i = 0; i < rows; i++){
        //code[i]=0;
        for(int j = 0; j < columns; j++ ){
            result[i] += H[i][j] * code[j];
        }
        result[i] %= 2;
    }
    return  result;
}

void Change(std::vector<int> &code, int i) {
    code[i]=(code[i])?0:1;

}

void Repair(std::vector<int> &msg){
    std::vector<int> error = Check(msg);
    for(int i = 0; i < columns; i++){
        bool isSame = false;
        for(int j = 0; j < rows; j++)
        {
            if(error[j] == H[j][i]){
                isSame = true;
            }
            else {
                isSame = false;
                break;
            }
        }
        if(isSame)
            Change(msg, i);

    }
    for(int i = 0; i < columns; i++){
        for(int j = 0; j < columns; j++){
            for(int k = 0; k < rows; k++){
                if((H[k][i] ^ H[k][j]) != error[k]) {
                    break;
                }
                if (k == rows - 1) {
                    Change(msg, i);
                    Change(msg, j);
                }
            }
        }
    }
}

void stringToInt(std::vector<int> &message, std::string text){
    for(int i = 0; i < text.size(); i++) {
        message.push_back((int)text[i] - 48);
    }
}

void coding(std::vector<int> &msg) {
    msg = Generate(G, msg);
    for(int i = 0; i < msg.size(); i++){
        std::cout<< msg[i];
    }
}

void decoding(std::vector<int> &msg) {


    std::vector<int> error = Check(msg);
    std::cout<<"\nWektor błędów:\n";
    for(int i = 0; i < error.size(); i++){
        std::cout << error[i];
    }
    std::cout << "\nOdkodowana wiadomość:\n";
    Repair(msg);
    error = Check(msg);
    for(int i = 0; i < error.size(); i++){
        if(error[i]) {
            std::cout << "Wiadomość ma więcej niż 2 błędy!\n";
            break;
        }
    }
    for(int i = 0; i < msg.size(); i++){
        std::cout << msg[i];
    }
    std::cout << '\n';
}

int main()
{
    int choice;
    do {
        std::cout << "1. Kodowanie\n"
                     "2. Dekodowanie\n"
                     "3. Zakończ\n";

        std::cin >> choice;
        if(choice == 1) {
            std::ifstream inputFile;
            std::ofstream outputFile;

            inputFile.open("message.txt");
            outputFile.open("coded_message.txt");
            std::string inputData;

            while(getline(inputFile, inputData))
            {
                if(inputData.size() == 8)
                {
                    std::vector<int> message;
                    stringToInt(message, inputData);
                    coding(message);
                    for(int i = 0; i < message.size(); i++)
                    {
                        outputFile << message[i];
                    }
                    outputFile << '\n';
                    std::cout << '\n';
                }
            }

            inputFile.close();
            outputFile.close();
        } else if (choice == 2) {

            std::ifstream inputFile;
            std::ofstream outputFile;

            inputFile.open("coded_message.txt");
            outputFile.open("decoded_message.txt");
            std::string inputData;

            while(getline(inputFile, inputData))
            {
                if(inputData.size() == columns)
                {
                    std::vector<int> message;
                    stringToInt(message, inputData);
                    decoding(message);
                    for(int i = 0; i < 8; i++)
                    {
                        outputFile << message[i];
                    }
                    outputFile << '\n';
                }
            }
            inputFile.close();
            outputFile.close();

        } else if (choice == 3)
            break;

        else
            std::cout << "Błędny wybór!\n";

    } while (true);

    return 0;
}