using System;
using System.Text;
using System.Threading.Tasks;
using IchniOnline.Online.Network;
using IchniOnline.Online.Network.Models;
using TapSDK.Login;
using UnityEngine;

namespace IchniOnline.Online.Network.Models
{
    [Serializable]
    public class SessionKeyResponseDto
    {
        public string SessionKey;
        public long ExpiresAt;
    }
}

namespace IchniOnline.Online.Logic
{
    /// <summary>
    /// Authentication orchestration service that coordinates TapTap login,
    /// password login, registration, and logout flows.
    /// Pure orchestration — no UI state management. Results are delivered via events.
    /// </summary>
    public static class IchniOnlineAuthService
    {
        /// <summary>
        /// 登录成功时触发，参数为服务端返回的登录响应（Register 成功时可能为 null）
        /// </summary>
        public static event Action<LoginResponseDto> OnLoginSuccess;

        /// <summary>
        /// 登录失败时触发，参数为错误信息
        /// </summary>
        public static event Action<string> OnLoginFailed;

        /// <summary>
        /// 登录被用户取消时触发
        /// </summary>
        public static event Action OnLoginCanceled;

        /// <summary>
        /// 是否正在进行登录流程，用于防止并发登录请求
        /// </summary>
        public static bool IsLoggingIn { get; private set; }

        #region TapTap Login

        /// <summary>
        /// 使用 TapTap 登录的完整流程：
        /// TapTap SDK → 第三方登录 API → JWT → 缓存 → 事件
        /// </summary>
        public static async void LoginWithTapTap()
        {
            if (IsLoggingIn)
            {
                Debug.LogWarning("[IchniOnlineAuthService] 已有登录流程正在进行中");
                return;
            }

            IsLoggingIn = true;

            Action<TapTapAccount> onSuccess = null;
            Action onCanceled = null;
            Action<string> onFailed = null;

            onSuccess = async account =>
            {
                UnsubscribeTapTapEvents(onSuccess, onCanceled, onFailed);

                if (account?.accessToken == null)
                {
                    IsLoggingIn = false;
                    OnLoginFailed?.Invoke("TapTap 登录成功但 accessToken 为空");
                    return;
                }

                var dto = new ThirdPartyLoginRequestDto
                {
                    Token = account.accessToken.kid,
                    TokenType = account.accessToken.tokenType,
                    MacKey = account.accessToken.macKey,
                    MacAlgorithm = account.accessToken.macAlgorithm
                };

                try
                {
                    var result = await IchniOnlineApiClient.Instance.PostAsync<LoginResponseDto>("/api/auth/third-party/login", dto);

                    IsLoggingIn = false;

                    if (result.IsSuccess)
                    {
                        LoginCacheManager.SaveAuthSession(result.Data.Token, result.Data);
                        IchniOnlineApiClient.Instance.JwtToken = result.Data.Token;
                        OnLoginSuccess?.Invoke(result.Data);
                    }
                    else
                    {
                        string errorMessage = $"第三方登录 API 失败: {result.Message}";
                        if (!string.IsNullOrEmpty(result.ErrorDetail))
                            errorMessage += $" ({result.ErrorDetail})";
                        OnLoginFailed?.Invoke(errorMessage);
                    }
                }
                catch (Exception ex)
                {
                    IsLoggingIn = false;
                    Debug.LogError($"[IchniOnlineAuthService] TapTap 登录 API 异常: {ex}");
                    OnLoginFailed?.Invoke($"TapTap 登录 API 异常: {ex.Message}");
                }
            };

            onCanceled = () =>
            {
                UnsubscribeTapTapEvents(onSuccess, onCanceled, onFailed);
                IsLoggingIn = false;
                OnLoginCanceled?.Invoke();
            };

            onFailed = errorMessage =>
            {
                UnsubscribeTapTapEvents(onSuccess, onCanceled, onFailed);
                IsLoggingIn = false;
                OnLoginFailed?.Invoke($"TapTap 登录失败: {errorMessage}");
            };

            ThirdPartyServiceManager.Instance.OnLoginSuccess += onSuccess;
            ThirdPartyServiceManager.Instance.OnLoginCanceled += onCanceled;
            ThirdPartyServiceManager.Instance.OnLoginFailed += onFailed;

            ThirdPartyServiceManager.Instance.StartTapTapLogin();
        }

        private static void UnsubscribeTapTapEvents(
            Action<TapTapAccount> onSuccess,
            Action onCanceled,
            Action<string> onFailed)
        {
            if (ThirdPartyServiceManager.Instance != null)
            {
                ThirdPartyServiceManager.Instance.OnLoginSuccess -= onSuccess;
                ThirdPartyServiceManager.Instance.OnLoginCanceled -= onCanceled;
                ThirdPartyServiceManager.Instance.OnLoginFailed -= onFailed;
            }
        }

        #endregion

        #region Password Login

        /// <summary>
        /// 使用用户名和密码登录的完整流程：
        /// 获取 session-key → XOR 加密密码 → 登录 API → JWT → 缓存 → 事件
        /// </summary>
        public static async void LoginWithPassword(string username, string password)
        {
            if (IsLoggingIn)
            {
                Debug.LogWarning("[IchniOnlineAuthService] 已有登录流程正在进行中");
                return;
            }

            if (string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password))
            {
                OnLoginFailed?.Invoke("用户名或密码不能为空");
                return;
            }

            IsLoggingIn = true;

            try
            {
                // 1. 获取 session-key
                var sessionResult = await IchniOnlineApiClient.Instance.GetAsync<SessionKeyResponseDto>("/api/auth/session-key");
                if (!sessionResult.IsSuccess)
                {
                    IsLoggingIn = false;
                    string errorMessage = $"获取 session-key 失败: {sessionResult.Message}";
                    if (!string.IsNullOrEmpty(sessionResult.ErrorDetail))
                        errorMessage += $" ({sessionResult.ErrorDetail})";
                    OnLoginFailed?.Invoke(errorMessage);
                    return;
                }

                string sessionKey = sessionResult.Data.SessionKey;

                // 2. XOR 加密密码
                string encryptedPassword = EncryptPassword(password, sessionKey);

                // 3. 调用登录 API
                var loginDto = new LoginRequestDto
                {
                    Username = username,
                    EncryptedPassword = encryptedPassword,
                    SessionKey = sessionKey
                };

                var loginResult = await IchniOnlineApiClient.Instance.PostAsync<LoginResponseDto>("/api/auth/login", loginDto);

                IsLoggingIn = false;

                if (loginResult.IsSuccess)
                {
                    LoginCacheManager.SaveAuthSession(loginResult.Data.Token, loginResult.Data);
                    IchniOnlineApiClient.Instance.JwtToken = loginResult.Data.Token;
                    OnLoginSuccess?.Invoke(loginResult.Data);
                }
                else
                {
                    string errorMessage = $"登录失败: {loginResult.Message}";
                    if (!string.IsNullOrEmpty(loginResult.ErrorDetail))
                        errorMessage += $" ({loginResult.ErrorDetail})";
                    OnLoginFailed?.Invoke(errorMessage);
                }
            }
            catch (Exception ex)
            {
                IsLoggingIn = false;
                Debug.LogError($"[IchniOnlineAuthService] 密码登录异常: {ex}");
                OnLoginFailed?.Invoke($"登录异常: {ex.Message}");
            }
        }

        #endregion

        #region Register

        /// <summary>
        /// 用户注册流程：POST /api/auth/register
        /// 注册成功后触发 OnLoginSuccess(null)（注册不返回 JWT）
        /// </summary>
        public static async void Register(string username, string password, string displayName)
        {
            if (IsLoggingIn)
            {
                Debug.LogWarning("[IchniOnlineAuthService] 已有登录流程正在进行中");
                return;
            }

            if (string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password))
            {
                OnLoginFailed?.Invoke("用户名或密码不能为空");
                return;
            }

            IsLoggingIn = true;

            try
            {
                var registerDto = new RegisterRequestDto
                {
                    Username = username,
                    Password = password,
                    DisplayName = displayName
                };

                var result = await IchniOnlineApiClient.Instance.PostAsync<object>("/api/auth/register", registerDto);

                IsLoggingIn = false;

                if (result.IsSuccess)
                {
                    OnLoginSuccess?.Invoke(null);
                }
                else
                {
                    string errorMessage = $"注册失败: {result.Message}";
                    if (!string.IsNullOrEmpty(result.ErrorDetail))
                        errorMessage += $" ({result.ErrorDetail})";
                    OnLoginFailed?.Invoke(errorMessage);
                }
            }
            catch (Exception ex)
            {
                IsLoggingIn = false;
                Debug.LogError($"[IchniOnlineAuthService] 注册异常: {ex}");
                OnLoginFailed?.Invoke($"注册异常: {ex.Message}");
            }
        }

        #endregion

        #region Logout

        /// <summary>
        /// 登出流程：清除本地会话、登出 TapTap、清除 API JWT Token
        /// </summary>
        public static void Logout()
        {
            LoginCacheManager.ClearSession();
            ThirdPartyServiceManager.Instance?.Logout();
            IchniOnlineApiClient.Instance.JwtToken = null;
            Debug.Log("[IchniOnlineAuthService] 已登出");
        }

        #endregion

        #region Encryption

        /// <summary>
        /// 使用 XOR 算法加密密码，与服务器 UserService.DecryptPassword 对应。
        /// sessionKey 为服务器返回的 Base64 字符串。
        /// </summary>
        public static string EncryptPassword(string password, string sessionKey)
        {
            if (string.IsNullOrEmpty(password))
                throw new ArgumentException("密码不能为空", nameof(password));
            if (string.IsNullOrEmpty(sessionKey))
                throw new ArgumentException("sessionKey 不能为空", nameof(sessionKey));

            byte[] passwordBytes = Encoding.UTF8.GetBytes(password);
            byte[] sessionBytes = Convert.FromBase64String(sessionKey);
            byte[] encrypted = new byte[passwordBytes.Length];

            for (int i = 0; i < passwordBytes.Length; i++)
            {
                encrypted[i] = (byte)(passwordBytes[i] ^ sessionBytes[i % sessionBytes.Length]);
            }

            return Convert.ToBase64String(encrypted);
        }

        #endregion
    }
}