using System;
using System.Configuration;
using System.Reflection;
using System.Text;
using System.Threading;
using XP.Common.License.Configs;
using XP.Common.License.Enums;
using XP.Common.License.Interfaces;
using XP.Common.License.Native;
using XP.Common.Logging.Interfaces;

namespace XP.Common.License.Implementations
{
    /// <summary>
    /// 授权服务实现 | License service implementation
    /// </summary>
    public class LicenseService : ILicenseService, IDisposable
    {
        /// <summary>
        /// 临时测试模式初始时间（秒）| Temporary test mode initial time (seconds)
        /// </summary>
        private const int TestModeInitialSeconds = 900;

        /// <summary>
        /// 授权配置 | License configuration
        /// </summary>
        private readonly LicenseConfig _config;

        /// <summary>
        /// 日志服务 | Logger service
        /// </summary>
        private readonly ILoggerService _logger;

        /// <summary>
        /// 同步锁对象 | Synchronization lock object
        /// </summary>
        private readonly object _lock = new object();

        /// <summary>
        /// 临时测试模式计时器 | Temporary test mode timer
        /// </summary>
        private Timer? _testModeTimer;

        /// <summary>
        /// 临时测试模式剩余时间（秒）| Temporary test mode remaining time (seconds)
        /// </summary>
        private int _remainingTestSeconds = TestModeInitialSeconds;

        /// <summary>
        /// 授权到期日期 | License expiration date
        /// </summary>
        private DateTime? _expirationDate;

        /// <summary>
        /// SMA到期日期 | SMA expiration date
        /// </summary>
        private DateTime? _smaDate;

        /// <summary>
        /// 浮动许可IP地址 | Floating license IP address
        /// </summary>
        private string? _floatingLicenseIp;

        /// <summary>
        /// 浮动许可端口 | Floating license port
        /// </summary>
        private string? _floatingLicensePort;

        /// <summary>
        /// 是否已释放 | Whether disposed
        /// </summary>
        private bool _disposed;

        /// <summary>
        /// 构造函数 | Constructor
        /// </summary>
        /// <param name="config">授权配置 | License configuration</param>
        /// <param name="logger">日志服务 | Logger service</param>
        public LicenseService(LicenseConfig config, ILoggerService logger)
        {
            _config = config ?? throw new ArgumentNullException(nameof(config));
            _logger = logger?.ForModule<LicenseService>() ?? throw new ArgumentNullException(nameof(logger));
            LicenseMode = (LicenseMode)_config.LicenseMode;
        }

        /// <summary>
        /// 当前会话是否已授权 | Whether the current session is authorized
        /// </summary>
        public bool IsAuthorized { get; private set; }

        /// <summary>
        /// 当前授权模式 | Current license mode
        /// </summary>
        public LicenseMode LicenseMode { get; private set; }

        /// <summary>
        /// 临时测试模式超时事件（到期时触发）| Temporary test mode timeout event (fires when expired)
        /// </summary>
        public event EventHandler? TestModeTimeout;

        /// <summary>
        /// 临时测试模式剩余5分钟警告事件 | Temporary test mode 5-minute warning event
        /// </summary>
        public event EventHandler? TestModeWarning5Min;

        /// <summary>
        /// 临时测试模式剩余1分钟警告事件 | Temporary test mode 1-minute warning event
        /// </summary>
        public event EventHandler? TestModeWarning1Min;

        /// <summary>
        /// 是否已触发5分钟警告 | Whether 5-minute warning has been fired
        /// </summary>
        private bool _warning5MinFired;

        /// <summary>
        /// 是否已触发1分钟警告 | Whether 1-minute warning has been fired
        /// </summary>
        private bool _warning1MinFired;

        /// <summary>
        /// 执行授权检查 | Perform authorization check
        /// </summary>
        /// <returns>授权检查结果 | License check result</returns>
        public LicenseCheckResult CheckAuthorization()
        {
            lock (_lock)
            {
                _logger.Info("开始授权检查，模式={Mode} | Starting authorization check, mode={Mode}", (int)LicenseMode);

                if (LicenseMode == Enums.LicenseMode.TemporaryTest)
                {
                    return HandleTemporaryTestMode();
                }

                return HandleClmsAuthorization();
            }
        }

        /// <summary>
        /// 获取授权到期日期 | Get license expiration date
        /// </summary>
        /// <returns>授权到期日期，未授权时返回 null | License expiration date, null if not authorized</returns>
        public DateTime? GetExpirationDate()
        {
            lock (_lock)
            {
                return _expirationDate;
            }
        }

        /// <summary>
        /// 检查模块是否授权 | Check if module is licensed
        /// </summary>
        /// <param name="moduleId">模块ID | Module ID</param>
        /// <returns>模块是否授权 | Whether the module is licensed</returns>
        public bool IsModuleLicensed(ushort moduleId)
        {
            lock (_lock)
            {
                if (!IsAuthorized)
                    return false;

                try
                {
                    ushort mod = moduleId;
                    ushort type = 0;
                    return NativeMethods.CLM_ModuleIsLicensed(ref mod, ref type);
                }
                catch (DllNotFoundException ex)
                {
                    _logger.Error(ex, "MORCODE.dll 加载失败 | Failed to load MORCODE.dll");
                    return false;
                }
                catch (EntryPointNotFoundException ex)
                {
                    _logger.Error(ex, "MORCODE.dll 中缺少入口点 | Missing entry point in MORCODE.dll");
                    return false;
                }
            }
        }

        /// <summary>
        /// 获取SMA到期日期 | Get SMA expiration date
        /// </summary>
        /// <returns>SMA到期日期，未启用时返回 null | SMA expiration date, null if not enabled</returns>
        public DateTime? GetSmaDate()
        {
            lock (_lock)
            {
                return _smaDate;
            }
        }

        /// <summary>
        /// 获取临时测试模式剩余时间 | Get remaining time in temporary test mode
        /// </summary>
        /// <returns>剩余时间（秒），非测试模式返回 -1 | Remaining time in seconds, -1 if not in test mode</returns>
        public int GetRemainingTestTime()
        {
            if (LicenseMode != Enums.LicenseMode.TemporaryTest)
                return -1;

            return Interlocked.CompareExchange(ref _remainingTestSeconds, 0, 0);
        }

        /// <summary>
        /// 释放资源 | Release resources
        /// </summary>
        public void Dispose()
        {
            if (_disposed)
                return;

            _disposed = true;

            // 停止计时器 | Stop timer
            _testModeTimer?.Dispose();
            _testModeTimer = null;

            // 尝试登出 | Try to logout
            try
            {
                NativeMethods.CLM_Logout();
            }
            catch (Exception ex)
            {
                _logger.Error(ex, "CLM_Logout 调用失败 | CLM_Logout call failed");
            }
        }

        /// <summary>
        /// 处理临时测试模式 | Handle temporary test mode
        /// </summary>
        /// <returns>授权检查结果 | License check result</returns>
        private LicenseCheckResult HandleTemporaryTestMode()
        {
            IsAuthorized = true;
            _remainingTestSeconds = TestModeInitialSeconds;

            // 启动计时器，每秒递减 | Start timer, decrement every second
            _testModeTimer?.Dispose();
            _testModeTimer = new Timer(TestModeTimerCallback, null, 1000, 1000);

            _logger.Info("临时测试模式已启动，剩余时间={Seconds}秒 | Temporary test mode started, remaining time={Seconds}s", TestModeInitialSeconds);

            WriteLicenseStateToConfig(LicenseState.Success);

            return new LicenseCheckResult(
                isAuthorized: true,
                message: "临时测试模式已启动，有效时间15分钟 | Temporary test mode started, valid for 15 minutes",
                licenseMode: Enums.LicenseMode.TemporaryTest,
                moduleId: _config.ModuleId,
                expirationDate: null,
                smaDate: null,
                floatingLicenseIp: null,
                floatingLicensePort: null);
        }

        /// <summary>
        /// 临时测试模式计时器回调 | Temporary test mode timer callback
        /// </summary>
        /// <param name="state">状态对象 | State object</param>
        private void TestModeTimerCallback(object? state)
        {
            int remaining = Interlocked.Decrement(ref _remainingTestSeconds);

            // 剩余5分钟（300秒）时触发警告 | Fire warning at 5 minutes (300 seconds) remaining
            if (remaining <= 300 && !_warning5MinFired)
            {
                _warning5MinFired = true;
                _logger.Warn("临时测试模式剩余5分钟 | Temporary test mode: 5 minutes remaining");
                TestModeWarning5Min?.Invoke(this, EventArgs.Empty);
            }

            // 剩余1分钟（60秒）时触发警告 | Fire warning at 1 minute (60 seconds) remaining
            if (remaining <= 60 && !_warning1MinFired)
            {
                _warning1MinFired = true;
                _logger.Warn("临时测试模式剩余1分钟 | Temporary test mode: 1 minute remaining");
                TestModeWarning1Min?.Invoke(this, EventArgs.Empty);
            }

            // 到期时触发超时事件 | Fire timeout event when expired
            if (remaining <= 0)
            {
                // 停止计时器 | Stop timer
                _testModeTimer?.Dispose();
                _testModeTimer = null;

                _logger.Info("临时测试模式已超时 | Temporary test mode has timed out");

                // 触发超时事件 | Raise timeout event
                TestModeTimeout?.Invoke(this, EventArgs.Empty);
            }
        }

        /// <summary>
        /// 处理 CLMS 正式授权流程 | Handle CLMS formal authorization flow
        /// 兼容新旧版本 SDK：对可能不存在的入口点使用 TryInvoke 优雅降级 | 
        /// Compatible with old/new SDK: gracefully degrades for missing entry points via TryInvoke
        /// </summary>
        /// <returns>授权检查结果 | License check result</returns>
        private LicenseCheckResult HandleClmsAuthorization()
        {
            try
            {
                // 步骤 1：检查系统时间（可选，老版本 SDK 可能不支持）| Step 1: Check system time (optional, old SDK may not support)
                if (!TryInvokeOptional(() => NativeMethods.CLM_CheckSystemTime(), "CLM_CheckSystemTime", out bool checkTimeResult))
                {
                    // 入口点不存在，跳过此步骤 | Entry point not found, skip this step
                    _logger.Warn("CLM_CheckSystemTime 入口点不存在，跳过系统时间检查（SDK版本较旧）| CLM_CheckSystemTime entry point not found, skipping system time check (older SDK version)");
                }
                else if (!checkTimeResult)
                {
                    _logger.Error(new InvalidOperationException("CLM_CheckSystemTime"), "系统时间检查异常 | System time check anomaly");
                    return CreateFailureResult("系统时间检查异常 | System time check anomaly");
                }
                else
                {
                    _logger.Info("系统时间检查正常 | System time check: OK");
                }

                // 步骤 2：登录验证（核心，必须存在）| Step 2: Login verification (core, must exist)
                StringBuilder password = new StringBuilder("FnEoFWSNLpVeoNWYhVoHLfgITRvieSszJfylVsXOTsLkphgkPzPhbLQzQrvRbNOkVVIQyMWkyGVjWSaiYUEksfQsRmklksLxrmeTksKKNMoZoWfZeDaLDSyWwEmtQakvSNxBMBLHoLEZHtaoXNpTWiaUGaSLQdsHFZnbRyPehytarNTKpaNNqnjFNggqWifhFsrZasDsWbIGWDrhnGrdtUNDMjJdhlTunsssxCzYpsLQrWBxUkuUUEJraSbTlbuX");
                if (!NativeMethods.CLM_Login(password))
                {
                    _logger.Error(new InvalidOperationException("CLM_Login"), "CLM_Login 登录验证失败 | CLM_Login verification failed");
                    return CreateFailureResult("CLM_Login 登录验证失败 | CLM_Login verification failed");
                }
                _logger.Info("CLM_Login 登录验证成功 | CLM_Login verification: OK");

                // 步骤 3：检查许可范围（核心，必须存在）| Step 3: Check license scope (core, must exist)
                if (!NativeMethods.CLM_Login_Scope())
                {
                    _logger.Error(new InvalidOperationException("CLM_Login_Scope"), "CLM_Login_Scope 许可范围检查失败 | CLM_Login_Scope scope check failed");
                    return CreateFailureResult("CLM_Login_Scope 许可范围检查失败 | CLM_Login_Scope scope check failed");
                }
                _logger.Info("CLM_Login_Scope 许可范围检查成功 | CLM_Login_Scope scope check: OK");

                // 步骤 4：SMA 验证（如果启用，可选入口点）| Step 4: SMA validation (if enabled, optional entry point)
                if (_config.UseSma)
                {
                    var smaResult = ValidateSma();
                    if (smaResult != null)
                        return smaResult;
                }
                else
                {
                    _logger.Info("放弃检查SMA | SMA check skipped");
                }

                // 步骤 5：获取浮动许可IP和端口（可选，老版本 SDK 可能不支持）| Step 5: Get floating license IP and port (optional, old SDK may not support)
                StringBuilder ip = new StringBuilder(256);
                StringBuilder port = new StringBuilder(256);
                if (!TryInvokeOptional(() => NativeMethods.CLM_GetIP(ip, port), "CLM_GetIP", out bool getIpResult))
                {
                    _logger.Warn("CLM_GetIP 入口点不存在，跳过浮动许可IP获取（SDK版本较旧）| CLM_GetIP entry point not found, skipping floating license IP retrieval (older SDK version)");
                }
                else if (!getIpResult)
                {
                    _logger.Error(new InvalidOperationException("CLM_GetIP"), "CLM_GetIP 获取浮动许可IP失败 | CLM_GetIP floating license IP retrieval failed");
                    return CreateFailureResult("CLM_GetIP 获取浮动许可IP失败 | CLM_GetIP floating license IP retrieval failed");
                }
                else
                {
                    _floatingLicenseIp = ip.ToString();
                    _floatingLicensePort = port.ToString();
                    _logger.Info("CLM_GetIP 成功: ip={Ip}/port={Port} | CLM_GetIP success: ip={Ip}/port={Port}", _floatingLicenseIp, _floatingLicensePort);
                }

                // 步骤 6：获取错误信息（可选，老版本 SDK 可能不支持）| Step 6: Get error message (optional, old SDK may not support)
                StringBuilder error = new StringBuilder(512);
                if (!TryInvokeOptional(() => NativeMethods.CLM_GetError(error), "CLM_GetError", out bool getErrorResult))
                {
                    _logger.Warn("CLM_GetError 入口点不存在，跳过错误信息获取（SDK版本较旧）| CLM_GetError entry point not found, skipping error retrieval (older SDK version)");
                }
                else if (!getErrorResult)
                {
                    _logger.Error(new InvalidOperationException("CLM_GetError"), "CLM_GetError 获取错误信息失败 | CLM_GetError error retrieval failed");
                    return CreateFailureResult("CLM_GetError 获取错误信息失败 | CLM_GetError error retrieval failed");
                }
                else
                {
                    _logger.Info("CLM_GetError 成功: {Error} | CLM_GetError success: {Error}", error.ToString());
                }

                // 步骤 7：检查模块授权（核心，必须存在）| Step 7: Check module authorization (core, must exist)
                ushort moduleId = _config.ModuleId;
                ushort type = 0;
                if (!NativeMethods.CLM_ModuleIsLicensed(ref moduleId, ref type))
                {
                    _logger.Error(new InvalidOperationException("CLM_ModuleIsLicensed"), "模块号码{ModuleId}不可用 | Module {ModuleId} unavailable", moduleId);
                    return CreateFailureResult($"模块号码{moduleId}不可用 | Module {moduleId} unavailable");
                }
                _logger.Info("模块号码{ModuleId}有效 | Module {ModuleId} available", moduleId);

                // 步骤 8：获取授权到期日期（核心，必须存在）| Step 8: Get warranty expiration date (core, must exist)
                int month = 0, day = 0, year = 0;
                if (!NativeMethods.CLM_GetWarrantyExpiration(ref month, ref day, ref year))
                {
                    _logger.Error(new InvalidOperationException("CLM_GetWarrantyExpiration"), "获取授权到期日期失败 | Failed to get warranty expiration date");
                    return CreateFailureResult("获取授权到期日期失败 | Failed to get warranty expiration date");
                }

                _expirationDate = new DateTime(year, month, day);
                _logger.Info("CLM_GetWarrantyExpiration 成功: {Year}/{Month}/{Day} | CLM_GetWarrantyExpiration success: {Year}/{Month}/{Day}", year, month, day);

                // 检查是否在30天内到期 | Check if expiring within 30 days
                string warningMessage = string.Empty;
                TimeSpan timeToExpiry = _expirationDate.Value - DateTime.Now;
                if (timeToExpiry.Days <= 30)
                {
                    warningMessage = $"软件授权将于{year}年{month}月{day}日到期，请尽快联系海克斯康 | Software license will expire on {year}-{month}-{day}, please contact Hexagon";
                    _logger.Warn(warningMessage);
                }

                // 授权成功 | Authorization successful
                IsAuthorized = true;
                WriteLicenseStateToConfig(LicenseState.Success);

                string successMessage = string.IsNullOrEmpty(warningMessage)
                    ? "授权检查成功 | Authorization check successful"
                    : $"授权检查成功（警告：{warningMessage}）| Authorization check successful (Warning: {warningMessage})";

                _logger.Info("授权检查完成 | Authorization check completed: Mode={Mode}, State={State}, Expiration={Expiration}",
                    (int)LicenseMode,
                    (int)LicenseState.Success,
                    _expirationDate?.ToString("yyyy-MM-dd") ?? "N/A");

                return new LicenseCheckResult(
                    isAuthorized: true,
                    message: successMessage,
                    licenseMode: LicenseMode,
                    moduleId: _config.ModuleId,
                    expirationDate: _expirationDate,
                    smaDate: _smaDate,
                    floatingLicenseIp: _floatingLicenseIp,
                    floatingLicensePort: _floatingLicensePort);
            }
            catch (DllNotFoundException ex)
            {
                _logger.Error(ex, "MORCODE.dll 加载失败 | Failed to load MORCODE.dll");
                return CreateFailureResult("CLMS SDK 不可用 | CLMS SDK unavailable");
            }
        }

        /// <summary>
        /// 尝试调用可选的 SDK 方法，兼容老版本 SDK 中不存在的入口点 |
        /// Try to invoke an optional SDK method, compatible with missing entry points in older SDK versions
        /// </summary>
        /// <param name="action">要调用的方法委托 | Method delegate to invoke</param>
        /// <param name="methodName">方法名称（用于日志）| Method name (for logging)</param>
        /// <param name="result">方法返回值，入口点不存在时为 default | Method return value, default if entry point not found</param>
        /// <returns>true: 入口点存在并已调用; false: 入口点不存在（EntryPointNotFoundException）| true: entry point exists and was invoked; false: entry point not found</returns>
        private bool TryInvokeOptional(Func<bool> action, string methodName, out bool result)
        {
            try
            {
                result = action();
                return true;
            }
            catch (EntryPointNotFoundException)
            {
                result = default;
                return false;
            }
        }

        /// <summary>
        /// 验证 SMA | Validate SMA
        /// 兼容老版本 SDK：CLM_GetSmaDate 入口点不存在时跳过 SMA 验证 |
        /// Compatible with old SDK: skips SMA validation if CLM_GetSmaDate entry point not found
        /// </summary>
        /// <returns>失败时返回失败结果，成功或跳过时返回 null | Returns failure result on failure, null on success or skip</returns>
        private LicenseCheckResult? ValidateSma()
        {
            int yearSma = 0, monthSma = 0, daySma = 0;

            // CLM_GetSmaDate 在老版本 SDK 中可能不存在 | CLM_GetSmaDate may not exist in older SDK
            try
            {
                if (!NativeMethods.CLM_GetSmaDate(ref monthSma, ref daySma, ref yearSma))
                {
                    _logger.Error(new InvalidOperationException("CLM_GetSmaDate"), "检查SMA失败 | SMA check failed");
                    return CreateFailureResult("检查SMA失败 | SMA check failed");
                }
            }
            catch (EntryPointNotFoundException)
            {
                _logger.Warn("CLM_GetSmaDate 入口点不存在，跳过SMA验证（SDK版本较旧）| CLM_GetSmaDate entry point not found, skipping SMA validation (older SDK version)");
                return null;
            }

            _logger.Info("CLM_GetSmaDate 成功: {Year}/{Month}/{Day} | CLM_GetSmaDate success: {Year}/{Month}/{Day}", yearSma, monthSma, daySma);

            // 获取软件版本信息 | Get software version information
            var version = Assembly.GetExecutingAssembly().GetName().Version;
            int major = version?.Major ?? 0;
            int minor = version?.Minor ?? 0;

            // SMA 年份 < 软件主版本号 → 失败 | SMA year < software major version → failure
            if (yearSma < major)
            {
                string msg = $"CLMS授权中SMA年份{yearSma}小于软件主版本号（年份）{major}，请联系海克斯康升级许可 | SMA year {yearSma} is less than software major version {major}, please contact Hexagon to upgrade license";
                _logger.Error(new InvalidOperationException("SMA验证失败"), msg);
                return CreateFailureResult(msg);
            }

            // SMA 年份 == 软件主版本号时，校验季度 | When SMA year == software major version, validate quarter
            if (yearSma == major)
            {
                try
                {
                    DateTime smaDate = new DateTime(yearSma, monthSma, daySma);
                    int smaQuarter = (smaDate.Month - 1) / 3 + 1;

                    if (minor > smaQuarter)
                    {
                        string msg = $"CLMS授权日期{yearSma}/{monthSma}/{daySma}属于{yearSma}年第{smaQuarter}季度，不支持当前{major}年第{minor}季度的软件版本 | SMA date {yearSma}/{monthSma}/{daySma} is in Q{smaQuarter} of {yearSma}, does not support current Q{minor} of {major} software version";
                        _logger.Error(new InvalidOperationException("SMA季度验证失败"), msg);
                        return CreateFailureResult(msg);
                    }
                }
                catch (Exception ex)
                {
                    string msg = $"SMA授权日期{yearSma}/{monthSma}/{daySma}不合法 | SMA date {yearSma}/{monthSma}/{daySma} is invalid: {ex.Message}";
                    _logger.Error(ex, msg);
                    return CreateFailureResult(msg);
                }
            }

            _smaDate = new DateTime(yearSma, monthSma, daySma);
            _logger.Info("SMA校验成功，SMA有效期至{Year}/{Month}/{Day} | SMA validation successful, valid until {Year}/{Month}/{Day}", yearSma, monthSma, daySma);
            return null;
        }

        /// <summary>
        /// 创建失败结果 | Create failure result
        /// </summary>
        /// <param name="message">失败消息 | Failure message</param>
        /// <returns>授权检查失败结果 | License check failure result</returns>
        private LicenseCheckResult CreateFailureResult(string message)
        {
            IsAuthorized = false;
            WriteLicenseStateToConfig(LicenseState.Fail);

            _logger.Info("授权检查完成 | Authorization check completed: Mode={Mode}, State={State}, Expiration={Expiration}",
                (int)LicenseMode,
                (int)LicenseState.Fail,
                "N/A");

            return new LicenseCheckResult(
                isAuthorized: false,
                message: message,
                licenseMode: LicenseMode,
                moduleId: _config.ModuleId,
                expirationDate: null,
                smaDate: _smaDate,
                floatingLicenseIp: _floatingLicenseIp,
                floatingLicensePort: _floatingLicensePort);
        }

        /// <summary>
        /// 写入授权状态到配置文件 | Write license state to configuration file
        /// </summary>
        /// <param name="state">授权状态 | License state</param>
        private void WriteLicenseStateToConfig(LicenseState state)
        {
            try
            {
                var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                var settings = config.AppSettings.Settings;

                if (settings["License:LicenseState"] == null)
                {
                    settings.Add("License:LicenseState", ((int)state).ToString());
                }
                else
                {
                    settings["License:LicenseState"].Value = ((int)state).ToString();
                }

                config.Save(ConfigurationSaveMode.Modified);
                ConfigurationManager.RefreshSection("appSettings");

                _logger.Info("授权状态已写入配置: {State} | License state written to config: {State}", (int)state);
            }
            catch (Exception ex)
            {
                _logger.Error(ex, "写入授权状态到配置失败 | Failed to write license state to config");
            }
        }
    }
}