#include <cstdlib>
#include <fstream>
#include <iostream>
#include <string>

#include "key.hpp"
#include "brute.hpp"

std::string me;
std::string encrypted;
std::string table_filename;
bool verbose = false;

#define ALPHABET_LENGTH 32

const char alphabet[ALPHABET_LENGTH] = {
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
        'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
        'y', 'z', '0', '1', '2', '3', '4', '5'
};

Brute::Brute(const std::string& filename) {
    T.resize(N);
    std::string buffer;
    std::fstream input(filename.c_str(), std::ios::in);
    for (int i = 0; i < N; i++) {
        std::getline(input, buffer);
        T[i].set_string(buffer);
    }
    input.close();
}

void Brute::decrypt(const std::string& encrypted){
    // your code here
    Key enc(encrypted);

    size_t length = encrypted.length();
    char zeroChars[length];
    char fullChars[length];
    for (int i = 0; i < length; i++) {
        zeroChars[i] = alphabet[0]; // Fill with a's.
    }
    for (int i = 0; i < length; i++) {
        fullChars[i] = alphabet[ALPHABET_LENGTH - 1]; // Fill with a's.
    }

    std::string zeroStr(zeroChars);
    std::string fullStr(fullChars);
    zeroChars[length - 1] = 'b'; // Set the rightmost char to b to equate the string to 1.
    std::string incStr(zeroChars);
    Key base(zeroStr);
    Key end(fullStr);
    Key inc(incStr);
    Key search = base; // Copy the base (all zero's).

    while (!(search == end)) {
        if (search.subset_sum(T, false) == enc) {
            search.show_string();
        }
        search += inc;
    }
}

void usage(const std::string& error_msg="") {
    if (!error_msg.empty()) std::cout << "ERROR: " << error_msg << '\n';
    std::cout << me << ": Brute force cracking of Subset-sum password with "
              << B << " bits precision\n"
              << "USAGE: " << me << " <encrypted> <table file> [options]\n"
              << "\nArguments:\n"
              << " <encrypted>:   encrypted password to crack\n"
              << " <table file>:  name of file containing the table to use\n"
              << "\nOptions:\n"
              << " -h|--help:     print this message\n"
              << " -v|--verbose:  select verbose mode\n\n";
    exit(0);
}

void initialize(int argc, char* argv[]) {
    me = argv[0];
    if (argc < 3) usage("Missing arguments");
    encrypted = argv[1];
    table_filename = argv[2];
    for (int i=3; i<argc; ++i) {
        std::string arg = argv[i];
        if (arg == "-h" || arg == "--help") usage();
        else if (arg == "-v" || arg == "--verbose") verbose = true;
        else usage("Unrecognized argument: " + arg);
    }
}


int main(int argc, char *argv[]){

    initialize(argc, argv);

    // your code here

    Brute brute(table_filename);
    brute.decrypt(encrypted);

    return 0;
}