#include <iostream>
#include <string>
#include <vector>
#include <stdint.h>
#include <future>

const uint32_t BASIS = 0x811c9dc5;
const uint32_t PRIME = 0x1000193;
const std::string CHARSET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";

uint32_t fnv1a(const std::string& s) {
    uint32_t hash = BASIS;
    for (unsigned char c : s) {
        hash ^= c;
        hash *= PRIME;
    }
    return hash;
}

// Recursive cracker for a specific segment
std::string crack(int length, uint32_t target) {
    std::string current(length, CHARSET[0]);
    
    auto backtrack = [&](auto self, int depth) -> bool {
        if (depth == length) {
            return fnv1a(current) == target;
        }
        for (char c : CHARSET) {
            current[depth] = c;
            if (self(self, depth + 1)) return true;
        }
        return false;
    };

    if (backtrack(backtrack, 0)) return current;
    return "?????";
}

int main() {
    struct Segment {
        int id;
        int len;
        uint32_t hash;
    };

    std::vector<Segment> segments = {
        {1, 4, 0x1fdb82eb}, // 7:11
        {2, 3, 0xc498c8a6}, // 12:15
        {3, 5, 0xd451383b}, // 16:21
        {4, 3, 0xf1d1bdc9}, // 22:25
        {5, 5, 0x5768cca7}, // 26:31
        {6, 3, 0xe25d1966}, // 32:35
        {7, 4, 0x45b2772b}  // 36:40
    };

    std::vector<std::future<std::string>> workers;
    std::cout << "[*] Launching 7 parallel threads for FNV-1a brute-force..." << std::endl;

    for (const auto& s : segments) {
        workers.push_back(std::async(std::launch::async, crack, s.len, s.hash));
    }

    std::vector<std::string> results;
    for (size_t i = 0; i < workers.size(); ++i) {
        std::string found = workers[i].get();
        results.push_back(found);
        std::cout << "[+] Segment " << i + 1 << " (" << segments[i].len << " chars): " << found << std::endl;
    }

    std::cout << "\n==========================================" << std::endl;
    std::cout << "FINAL FLAG: kalmar{";
    for (size_t i = 0; i < results.size(); ++i) {
        std::cout << results[i] << (i == results.size() - 1 ? "" : "_");
    }
    std::cout << "}" << std::endl;
    std::cout << "==========================================" << std::endl;

    return 0;
}