#include "message.h"

#include <algorithm>
#include <array>
#include <cassert>
#include <iostream>
#include <random>
#include <vector>

std::vector<bool> gen1(int n, int seed = 2086) {
    std::mt19937 rnd(seed);
    std::vector<bool> res(n);
    for (int i = 0; i < n; i++) {
        res[i] = rnd() % 2;
    }
    return res;
}

constexpr int SC = 17;
const std::vector<bool> M_xor = gen1(2000, 1232131);
const std::vector<bool> data_xor = gen1(10000, 787);

void send_message(std::vector<bool> M, std::vector<bool> C) {
    for (int i = 0; i < M.size(); i++) {
        M[i] = M[i] ^ M_xor[i];
    }
    M.push_back(true);

    std::vector<std::vector<int>> data(30 + SC, std::vector<int>(31, -1));
    int it = std::find(C.begin(), C.end(), false) - C.begin();
    for (int i = 0; i < 30; i++) {
        data[i][it] = C[i + (i >= it)];
    }
    for (int i = 0; i < SC; i++) {
        data[i + 30][it] = 0;
    }

    int m_ptr = 0;
    data.resize(data.size() + std::max(0, ((int)M.size() - (int)data.size() * 15) / 16));

    for (int i = 0; i < data.size(); i++) {
        for (int j = 0; j < 31; j++) {
            if (!C[j] && data[i][j] == -1) {
                data[i][j] = m_ptr == M.size() ? 0 : M[m_ptr++];
            }
        }
    }
    {
        std::mt19937 rnd(336);
        for (int i = 0; i < data.size(); i++) {
            for (int j = 0; j < 31; j++) {
                assert((data[i][j] == -1) == (C[j]));
                if (data[i][j] == -1) {
                    data[i][j] = rnd() % 2;
                }
            }
        }
    }

    for (int i = 0; i < data.size(); i++) {
        for (int j = 0; j < 31; j++) {
            data[i][j] = data[i][j] ^ data_xor[i * 31 + j];
        }
    }
    for (auto pck : data) {
        send_packet(std::vector<bool>(pck.begin(), pck.end()));
    }
}

std::vector<bool> receive_message(std::vector<std::vector<bool>> R) {
    for (int i = 0; i < R.size(); i++) {
        for (int j = 0; j < 31; j++) {
            R[i][j] = R[i][j] ^ data_xor[i * 31 + j];
        }
    }

    int ind = -1;
    std::vector<int> C(31, -1);
    for (int i = 0; i < 31; i++) {
        int cnt0 = 0, cnt1 = 0;
        for (int j = 0; j < 30; j++) {
            cnt0 += R[j][i];
        }
        for (int j = 0; j < SC; j++) {
            cnt1 += R[j + 30][i];
        }
        if (cnt0 == 15 && cnt1 == 0) {
            ind = i;
            C[i] = 0;
            for (int j = 0; j < 30; j++) {
                C[j + (j >= i)] = R[j][i];
            }
            break;
        }
    }
    assert(ind != -1);

    std::vector<bool> res;
    for (int i = 0; i < R.size(); i++) {
        for (int j = 0; j < 31; j++) {
            if (C[j] == 0 && (i >= 30 + SC || j != ind)) {
                res.push_back(R[i][j]);
            }
        }
    }

    while (!res.back()) {
        res.pop_back();
    }
    res.pop_back();

    for (int i = 0; i < res.size(); i++) {
        res[i] = res[i] ^ M_xor[i];
    }
    return res;
}