#include "common/Crypto.h"

#include <drogon/utils/Utilities.h>

#include <iomanip>
#include <random>
#include <sstream>
#include <string>

namespace visione::crypto
{
std::string sha256(const std::string &value)
{
    return drogon::utils::getSha256(value);
}

std::string randomNumericCode(int digits)
{
    std::random_device device;
    std::mt19937 generator(device());
    std::uniform_int_distribution<int> distribution(0, 9);

    std::string code;
    code.reserve(static_cast<size_t>(digits));
    for (int i = 0; i < digits; ++i)
    {
        code.push_back(static_cast<char>('0' + distribution(generator)));
    }
    return code;
}

std::string randomToken()
{
    return drogon::utils::getUuid() + drogon::utils::getUuid();
}

std::string hashPassword(const std::string &password)
{
    const auto salt = drogon::utils::getUuid();
    return "sha256$" + salt + "$" + sha256(salt + ":" + password);
}

bool verifyPassword(const std::string &password, const std::string &hash)
{
    constexpr std::string_view prefix = "sha256$";
    if (!hash.starts_with(prefix))
    {
        return false;
    }

    const auto saltStart = prefix.size();
    const auto hashStart = hash.find('$', saltStart);
    if (hashStart == std::string::npos)
    {
        return false;
    }

    const auto salt = hash.substr(saltStart, hashStart - saltStart);
    const auto expected = "sha256$" + salt + "$" + sha256(salt + ":" + password);
    return expected == hash;
}

std::string hashSecret(const std::string &secret)
{
    return sha256("visione:" + secret);
}
}  // namespace visione::crypto