#include "stdafx.h"
#include "UserManager.h"
#include <chrono>
#include <iostream>
#include <fstream>
#include <ctime>
#include <sstream>

const std::string SESSION_FILE = R"(session.dat)";
const std::string DATABASE_FILE = R"(UserManager.db)";

const std::string INITIAL_ADMIN_USERNAME = "admin";
const std::string INITIAL_ADMIN_PASSWORD = "admin";

// 获取单例实例
UserManager& UserManager::getInstance() {
	static UserManager instance;
	return instance;
}

UserManager::UserManager()
	: m_isLoggedIn(false), m_isRememberMe(false), m_tmSessionTimeout(std::chrono::minutes(30)),
	m_tmSessionExpiration(std::chrono::hours(72)), m_hMouseHook(nullptr), m_hKeyboardHook(nullptr),
	m_pDB(std::make_unique<BL::SQLiteDatabase>()) {
	initializeDatabase();
}

UserManager::~UserManager() {
	terminateIdleDetection();
}

// 提供数据库连接
std::unique_ptr<BL::Database>& UserManager::getDatabaseInstance() {
	return m_pDB;
}

// 初始化数据库，创建用户表并插入初始管理员用户
bool UserManager::initializeDatabase() {
	std::string dbFilePath = getDatabaseFilePath();
	if (!m_pDB->connect(dbFilePath, true)) {
		throw std::runtime_error("Failed to connect to database.");
	}

	std::string createTableQuery = R"(
		CREATE TABLE IF NOT EXISTS users (
			username VARCHAR(50) PRIMARY KEY,
			password VARCHAR(255) NOT NULL,
			role INT NOT NULL,
			session_timeout INT DEFAULT 30,
			session_expiration INT DEFAULT 72,
			last_login DATETIME DEFAULT (datetime('now', 'localtime'))
		)
	)";
	m_pDB->executeQuery(createTableQuery);

	std::string checkAdminQuery = "SELECT COUNT(*) FROM users WHERE role = 0";
	auto result = m_pDB->fetchResults(checkAdminQuery);

	if (result.empty() || result[0][0] == "0") {
		std::string insertAdminQuery = "INSERT INTO users (username, password, role, session_timeout, session_expiration) VALUES ('" +
			INITIAL_ADMIN_USERNAME + "', '" + simpleEncryptDecrypt(INITIAL_ADMIN_PASSWORD, "BandKey") + "', 0, 30, 72)";
		m_pDB->executeQuery(insertAdminQuery);
	}

	return true;
}

// 对密码进行哈希处理
std::string UserManager::hashPassword(const std::string& password) {
	return std::to_string(std::hash<std::string>{}(password));
}

// 简单的加密和解密函数
std::string UserManager::simpleEncryptDecrypt(const std::string& data, const std::string& key) {
	std::string result = data;
	for (size_t i = 0; i < data.size(); ++i) {
		result[i] ^= key[i % key.size()];  // 简单异或加密
	}
	return result;
}

// 从会话文件加载会话信息
bool UserManager::loadSession() {
	std::ifstream sessionFile(getSessionFilePath(), std::ios::binary);
	if (!sessionFile.is_open()) {
		return false;
	}

	// 从文件读取加密数据
	std::string encryptedData((std::istreambuf_iterator<char>(sessionFile)), std::istreambuf_iterator<char>());
	sessionFile.close();

	// 解密数据
	std::string decryptedData = simpleEncryptDecrypt(encryptedData, "my_secret_key");

	// 解析解密的数据
	std::istringstream sessionData(decryptedData);
	std::string username;
	std::string password;
	std::time_t lastLoginTime;
	int timeoutMinutes;
	int expirationHours;

	sessionData >> username >> password >> lastLoginTime >> timeoutMinutes >> expirationHours;

	// 验证时间戳有效性
	auto now = std::chrono::system_clock::now();
	auto lastLogin = std::chrono::system_clock::from_time_t(lastLoginTime);
	auto sessionDuration = std::chrono::duration_cast<std::chrono::hours>(now - lastLogin);

	if (sessionDuration > std::chrono::hours(expirationHours)) {
		clearSession();
		return false;
	}

	// 恢复会话数据
	m_strCurrentUser = username;
	m_strCurrentPass = password;
	m_tpLastLogin = lastLogin;
	m_tmSessionTimeout = std::chrono::minutes(timeoutMinutes);
	m_tmSessionExpiration = std::chrono::hours(expirationHours);
	m_isLoggedIn = true;
	m_isRememberMe = true;
	updateActivityTime();

	return true;
}

// 保存会话信息到文件
void UserManager::saveSession() {
	if (!m_isRememberMe) {
		clearSession();
		return;
	}

	// 原始会话数据
	std::stringstream sessionData;
	std::time_t lastLoginTime = std::chrono::system_clock::to_time_t(m_tpLastLogin);
	sessionData << m_strCurrentUser << " " << m_strCurrentPass << " " << lastLoginTime << " "
		<< m_tmSessionTimeout.count() << " " << m_tmSessionExpiration.count();

	// 加密数据
	std::string encryptedData = simpleEncryptDecrypt(sessionData.str(), "my_secret_key");

	// 写入加密数据到文件
	std::ofstream sessionFile(getSessionFilePath(), std::ios::binary);
	if (sessionFile.is_open()) {
		sessionFile << encryptedData;
		sessionFile.close();
	}
}

// 清除会话文件
void UserManager::clearSession() {
	std::remove(getSessionFilePath().c_str());
}

// 获取程序路径下的config文件夹路径
std::string UserManager::getConfigFolderPath() {
	char szPath[MAX_PATH];
	GetModuleFileName(NULL, szPath, MAX_PATH);
	std::string exePath(szPath);
	std::string dbDir = exePath.substr(0, exePath.find_last_of("\\/")) + "\\DB\\";

	// 检查并创建config文件夹
	DWORD fileAttr = GetFileAttributes(dbDir.c_str());
	if (fileAttr == INVALID_FILE_ATTRIBUTES) {
		CreateDirectory(dbDir.c_str(), NULL);
	}

	return dbDir;
}

// 获取session.dat文件路径
std::string UserManager::getSessionFilePath() {
	return getConfigFolderPath() + SESSION_FILE;
}

// 获取数据库文件路径
std::string UserManager::getDatabaseFilePath() {
	return getConfigFolderPath() + DATABASE_FILE;
}

// 登录方法
bool UserManager::login(const std::string& username, const std::string& password, bool rememberMeFlag) {
	std::string query = "SELECT username, password, role, session_timeout, session_expiration FROM users WHERE username = '" + username + "'";
	auto result = m_pDB->fetchResults(query);

	if (result.empty() || result[0][1] != simpleEncryptDecrypt(password, "BandKey")) {
		std::cerr << "Login failed: Invalid username or password." << std::endl;
		return false;
	}

	m_strCurrentUser = username;
	m_strCurrentPass = password;
	m_enCurrentUserRole = static_cast<UserRole>(std::stoi(result[0][2]));
	m_tmSessionTimeout = std::chrono::minutes(std::stoi(result[0][3]));
	m_tmSessionExpiration = std::chrono::hours(std::stoi(result[0][4]));
	m_isLoggedIn = true;
	m_isRememberMe = rememberMeFlag;
	updateActivityTime();
	m_tpLastLogin = std::chrono::system_clock::now();

	std::string updateLoginTime = "UPDATE users SET last_login = CURRENT_TIMESTAMP WHERE username = '" + username + "'";
	m_pDB->executeQuery(updateLoginTime);

	saveSession();
	return true;
}

// 登出方法
void UserManager::logout() {
	if (m_isLoggedIn) {
		std::cout << "User logged out: " << m_strCurrentUser << std::endl;
		m_strCurrentUser.clear();
		m_strCurrentPass.clear();
		m_isLoggedIn = false;
		m_isRememberMe = false;
		clearSession();
	}
}

// 返回当前用户的登录状态
bool UserManager::isLoggedIn() const {
	return m_isLoggedIn;
}

// 返回当前用户的记住登录状态
bool UserManager::isRememberMe() const {
	return m_isRememberMe;
}

// 创建新用户，仅超级管理员有权限
bool UserManager::createUser(const std::string& username, const std::string& password, UserRole role,
	std::chrono::minutes timeout, std::chrono::hours expiration) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can create new users." << std::endl;
		return false;
	}

	std::string query = "INSERT INTO users (username, password, role, session_timeout, session_expiration) VALUES ('" +
		username + "', '" + simpleEncryptDecrypt(password, "BandKey") + "', " + std::to_string(static_cast<int>(role)) + ", " +
		std::to_string(timeout.count()) + ", " + std::to_string(expiration.count()) + ")";
	return m_pDB->executeQuery(query);
}

// 删除用户，仅超级管理员有权限，且不能删除自己
bool UserManager::deleteUser(const std::string& username) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can delete users." << std::endl;
		return false;
	}
	if (username == m_strCurrentUser) {
		std::cerr << "SuperAdmin cannot delete their own account." << std::endl;
		return false;
	}

	std::string query = "DELETE FROM users WHERE username = '" + username + "'";
	return m_pDB->executeQuery(query);
}

// 获取所有用户信息，仅超级管理员有权限
std::vector<std::vector<std::string>> UserManager::getUsers() {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can retrieve user data." << std::endl;
		return {};
	}

	// 查询整个用户表
	std::string query = "SELECT username, password, role, session_timeout, session_expiration, last_login FROM users";
	std::vector<std::vector<std::string>> results = m_pDB->fetchResults(query);
	for (auto& row : results) {
		row[1] = simpleEncryptDecrypt(row[1], "BandKey");
	}

	return results;
}

// 设置整个用户表的数据，仅超级管理员有权限
bool UserManager::setUsers(const std::vector<std::vector<std::string>>& usersData) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can set user data." << std::endl;
		return false;
	}

	// 清空用户表
	std::string deleteQuery = "DELETE FROM users";
	if (!m_pDB->executeQuery(deleteQuery)) {
		std::cerr << "Failed to clear the users table." << std::endl;
		return false;
	}

	// 插入新的用户数据
	for (const auto& user : usersData) {
		if (user.size() != 6) {
			std::cerr << "Invalid data format for user. Each user must have 6 fields." << std::endl;
			return false;
		}

		std::string insertQuery = "INSERT INTO users (username, password, role, session_timeout, session_expiration, last_login) VALUES ('" +
			user[0] + "', '" + simpleEncryptDecrypt(user[1], "BandKey") + "', " + user[2] + ", " + user[3] + ", " + user[4] + ", '" + user[5] + "')";

		if (!m_pDB->executeQuery(insertQuery)) {
			std::cerr << "Failed to insert user: " << user[0] << std::endl;
			return false;
		}
	}

	return true;
}

// 修改用户名，仅超级管理员有权限
bool UserManager::changeUsername(const std::string& username, const std::string& newUsername) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can change usernames." << std::endl;
		return false;
	}

	std::string query = "UPDATE users SET username = '" + newUsername + "' WHERE username = '" + username + "'";
	bool success = m_pDB->executeQuery(query);

	// 如果是当前登录用户修改自己的用户名，更新成员变量并保存会话文件
	if (success && m_strCurrentUser == username) {
		m_strCurrentUser = newUsername;

		// 如果“记住密码”已启用，更新会话文件
		if (m_isRememberMe) {
			saveSession();
		}
	}
	return success;
}

// 修改用户密码（仅允许当前用户或超级管理员）
bool UserManager::changePassword(const std::string& username, const std::string& newPassword) {
	if (username != m_strCurrentUser && m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Permission denied: Only the user or SuperAdmin can change passwords." << std::endl;
		return false;
	}

	std::string query = "UPDATE users SET password = '" + simpleEncryptDecrypt(newPassword, "BandKey") +
		"' WHERE username = '" + username + "'";
	bool success = m_pDB->executeQuery(query);

	// 如果是当前用户修改自己的密码，退出登录并清除会话文件
	if (success && m_strCurrentUser == username) {
		logout();
		std::cout << "Password changed successfully. Please log in again." << std::endl;
	}

	return success;
}

// 更改用户角色，仅超级管理员有权限
bool UserManager::changeUserRole(const std::string& username, UserRole newRole) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can change user roles." << std::endl;
		return false;
	}

	// 防止管理员更改自己的角色
	if (m_strCurrentUser == username) {
		std::cerr << "SuperAdmin cannot change their own role." << std::endl;
		return false;
	}

	std::string query = "UPDATE users SET role = " + std::to_string(static_cast<int>(newRole)) +
		" WHERE username = '" + username + "'";
	return m_pDB->executeQuery(query);
}

// 修改用户的 session_timeout，仅超级管理员有权限
bool UserManager::changeUserSessionTimeout(const std::string& username, int newTimeoutMinutes) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can change session timeout." << std::endl;
		return false;
	}

	std::string query = "UPDATE users SET session_timeout = " + std::to_string(newTimeoutMinutes) +
		" WHERE username = '" + username + "'";
	bool success = m_pDB->executeQuery(query);
	// 如果是当前登录用户修改自己的超时设置，更新成员变量
	if (success && m_strCurrentUser == username) {
		m_tmSessionTimeout = std::chrono::minutes(newTimeoutMinutes);

		if (m_isRememberMe) {
			saveSession();
		}
	}
	return success;
}

// 修改用户的 session_expiration，仅超级管理员有权限
bool UserManager::changeUserSessionExpiration(const std::string& username, int newExpirationHours) {
	if (m_enCurrentUserRole != UserRole::SuperAdmin) {
		std::cerr << "Only SuperAdmin can change session expiration." << std::endl;
		return false;
	}

	std::string query = "UPDATE users SET session_expiration = " + std::to_string(newExpirationHours) +
		" WHERE username = '" + username + "'";
	bool success = m_pDB->executeQuery(query);
	// 如果是当前登录用户修改自己的过期设置，更新成员变量
	if (success && m_strCurrentUser == username) {
		m_tmSessionExpiration = std::chrono::hours(newExpirationHours);

		if (m_isRememberMe) {
			saveSession();
		}
	}
	return success;
}

// 获取所有用户名称
std::vector<std::string> UserManager::getUsernames() {
	std::vector<std::string> usernames;
	std::string query = "SELECT username FROM users";
	auto results = m_pDB->fetchResults(query);

	for (const auto& row : results) {
		if (!row.empty()) {
			usernames.push_back(row[0]); // 获取用户名列的值
		}
	}

	return usernames;
}

// 获取指定用户名的用户信息
std::vector<std::string> UserManager::getUserInfo(const std::string& username)
{
	// 构建查询语句
	std::ostringstream query;
	query << "SELECT username, password, role, session_timeout, session_expiration, last_login "
		<< "FROM users WHERE username = '" << username << "'";

	// 执行查询并获取结果
	auto results = m_pDB->fetchResults(query.str());
	if (results.empty()) {
		return {};
	}

	// 返回查询到的第一行数据
	return results[0];
}

// 更新最后活动时间，用于无操作超时检测
void UserManager::updateActivityTime() {
	m_tpLastActivity = std::chrono::system_clock::now();
	std::cout << "Activity updated at: " << std::chrono::system_clock::to_time_t(m_tpLastActivity) << std::endl;
}

// 设置无操作超时时间
void UserManager::setSessionTimeout(std::chrono::minutes timeout) {
	m_tmSessionTimeout = timeout;
}

// 检查是否超过无操作超时时间
bool UserManager::isInactiveTimeout() const {
	auto now = std::chrono::system_clock::now();
	auto elapsedSeconds = std::chrono::duration_cast<std::chrono::seconds>(now - m_tpLastActivity).count();
	return elapsedSeconds > m_tmSessionTimeout.count() * 60;
}

// 初始化无操作检测，包括设置全局鼠标和键盘钩子
void UserManager::initializeIdleDetection(HWND hwnd) {
	updateActivityTime();
	m_hMouseHook = SetWindowsHookEx(WH_MOUSE_LL, LowLevelMouseProc, (HINSTANCE) nullptr, 0);
	m_hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, (HINSTANCE) nullptr, 0);
	::SetTimer(hwnd, 1, 60000, nullptr);
}

// 终止无操作检测，清除鼠标和键盘钩子
void UserManager::terminateIdleDetection() {
	if (m_hMouseHook) {
		UnhookWindowsHookEx(m_hMouseHook);
		m_hMouseHook = nullptr;
	}
	if (m_hKeyboardHook) {
		UnhookWindowsHookEx(m_hKeyboardHook);
		m_hKeyboardHook = nullptr;
	}
	::KillTimer(nullptr, 1);
}

// 获取当前登录用户名
std::string UserManager::getCurrentUser() const {
	return m_strCurrentUser;
}

// 修改当前登录用户名
void UserManager::setCurrentUser(const std::string& strName) {
	m_strCurrentUser = strName;
}

// 获取当前登录用户密码
std::string UserManager::getCurrentPass() const {
	return m_strCurrentPass;
}

// 修改当前登录用户密码
void UserManager::setCurrentPass(const std::string& strPass) {
	m_strCurrentPass = strPass;
}

// 获取当前登录用户角色
UserRole UserManager::getCurrentUserRole() const {
	return m_enCurrentUserRole;
}

// 修改当前登录用户角色
void UserManager::setCurrentUserRole(UserRole emRole) {
	m_enCurrentUserRole = emRole;
}

// 获取当前登录用户的无操作超时时间
std::chrono::minutes UserManager::getSessionTimeout() const {
	return m_tmSessionTimeout;
}

// 获取当前登录用户的会话过期时间
std::chrono::hours UserManager::getSessionExpiration() const {
	return m_tmSessionExpiration;
}

// 全局鼠标钩子回调，记录活动时间
LRESULT CALLBACK UserManager::LowLevelMouseProc(int nCode, WPARAM wParam, LPARAM lParam) {
	if (nCode == HC_ACTION) {
		UserManager::getInstance().updateActivityTime();
		std::cout << "Mouse event detected. Activity time updated." << std::endl;
	}
	return CallNextHookEx(nullptr, nCode, wParam, lParam);
}

// 全局键盘钩子回调，记录活动时间
LRESULT CALLBACK UserManager::LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam) {
	if (nCode == HC_ACTION) {
		UserManager::getInstance().updateActivityTime();
		std::cout << "Keyboard event detected. Activity time updated." << std::endl;
	}
	return CallNextHookEx(nullptr, nCode, wParam, lParam);
}