#include "infrastructure/repositories/FileUserRepository.h"
#include "nlohmann/json.hpp"
#include <fstream>
#include <algorithm>

namespace nxl::autostore::infrastructure {

namespace {

// Helper functions for JSON serialization
inline void userToJson(nlohmann::json& j, const domain::User& u)
{
  j = nlohmann::json{
    {"id", u.id}, {"username", u.username}, {"passwordHash", u.passwordHash}};
}

inline void jsonToUser(const nlohmann::json& j, domain::User& u)
{
  j.at("id").get_to(u.id);
  j.at("username").get_to(u.username);
  j.at("passwordHash").get_to(u.passwordHash);
}

// Helper functions for vector serialization
inline nlohmann::json usersToJson(const std::vector<domain::User>& users)
{
  nlohmann::json j = nlohmann::json::array();
  for (const auto& user : users) {
    nlohmann::json userJson;
    userToJson(userJson, user);
    j.push_back(userJson);
  }
  return j;
}

inline std::vector<domain::User> jsonToUsers(const nlohmann::json& j)
{
  std::vector<domain::User> users;
  for (const auto& userJson : j) {
    domain::User user;
    jsonToUser(userJson, user);
    users.push_back(user);
  }
  return users;
}

} // namespace

FileUserRepository::FileUserRepository(std::string_view dbPath) : dbPath(dbPath)
{
  load();
}

void FileUserRepository::save(const domain::User& user)
{
  std::lock_guard<std::mutex> lock(mtx);
  auto it =
    std::find_if(users.begin(), users.end(),
                 [&](const domain::User& u) { return u.id == user.id; });

  if (it != users.end()) {
    *it = user;
  } else {
    users.push_back(user);
  }
  persist();
}

std::optional<domain::User> FileUserRepository::findById(std::string_view id)
{
  std::lock_guard<std::mutex> lock(mtx);
  auto it = std::find_if(users.begin(), users.end(),
                         [&](const domain::User& u) { return u.id == id; });

  if (it != users.end()) {
    return *it;
  }
  return std::nullopt;
}

std::optional<domain::User>
FileUserRepository::findByUsername(std::string_view username)
{
  std::lock_guard<std::mutex> lock(mtx);
  auto it =
    std::find_if(users.begin(), users.end(),
                 [&](const domain::User& u) { return u.username == username; });

  if (it != users.end()) {
    return *it;
  }
  return std::nullopt;
}

std::vector<domain::User> FileUserRepository::findAll()
{
  std::lock_guard<std::mutex> lock(mtx);
  return users;
}

void FileUserRepository::remove(std::string_view id)
{
  std::lock_guard<std::mutex> lock(mtx);
  users.erase(std::remove_if(users.begin(), users.end(),
                             [&](const domain::User& u) { return u.id == id; }),
              users.end());
  persist();
}

void FileUserRepository::load()
{
  std::lock_guard<std::mutex> lock(mtx);
  std::ifstream file(dbPath);
  if (file.is_open()) {
    nlohmann::json j;
    file >> j;
    users = jsonToUsers(j);
  }
}

void FileUserRepository::persist()
{
  std::ofstream file(dbPath);
  if (file.is_open()) {
    nlohmann::json j = usersToJson(users);
    file << j.dump(4);
  }
}

} // namespace nxl::autostore::infrastructure