using Common.Shared.Application.DaHua;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using System.Net.Http.Json;
using System.Security.Cryptography;
using System.Text.Json;

namespace Common.Shared.DomainService
{
    /// <summary>
    /// 获取大华icc平台的token服务
    /// </summary>
    public class TokenProviderService : ITokenProviderService
    {
        private readonly IConfiguration _configuration;
        private readonly ILogger<TokenProviderService> _logger;

        public TokenProviderService(IConfiguration configuration, ILogger<TokenProviderService> logger)
        {
            _configuration = configuration;
            _logger = logger;
        }

        /// <summary>
        /// 开发测试的时候，忽略证书
        /// </summary>
        private static readonly HttpClient _http = new(new HttpClientHandler
        {
            ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator
        });

        public async Task<string> GetTokenAsync(string clientId)
        {
            if (TokenCache.TokenMap.TryGetValue(clientId, out var tokenEntry)
        && tokenEntry.ExpireAt > DateTimeOffset.UtcNow.AddMinutes(5))
            {
                return tokenEntry.AccessToken!;
            }

            var tokenLock = TokenLockProvider.GetLock(clientId);
            await tokenLock.WaitAsync();
            try
            {
                // 加锁后再次检查，防止重复刷新
                if (TokenCache.TokenMap.TryGetValue(clientId, out tokenEntry)
                    && tokenEntry.ExpireAt > DateTimeOffset.UtcNow.AddMinutes(5))
                {
                    return tokenEntry.AccessToken!;
                }

                var refreshed = await TryRefreshOrLoginAsync(clientId, tokenEntry);

                return refreshed.AccessToken;
            }
            finally
            {
                tokenLock.Release();
            }
        }

        private async Task<TokenEntry> TryRefreshOrLoginAsync(string clientId, TokenEntry? current)
        {
            try
            {
                TokenEntry refreshed;

                if (current?.AccessToken is { } refreshToken)
                {
                    var dto = new RefreshTokenReqDto
                    {
                        ClientId = clientId,
                        ClientSecret = _configuration["DahuaAuth:ClientSecret"]!,
                        GrantType = "refresh_token",
                        //刷新要求去掉 Bearer 前缀
                        RefreshToken = refreshToken.Replace("Bearer ", string.Empty)
                    };

                    var result = await RefreshToken(dto);

                    if (result?.Data != null && result.Data.AccessToken != "" && result.Data.AccessToken != null)
                    {
                        refreshed = new TokenEntry
                        {
                            AccessToken = string.Concat(result.Data.TokenType, " ", result.Data.AccessToken),

                            ExpireAt = DateTimeOffset.UtcNow.AddSeconds(result.Data.ExpiresIn)
                        };
                        _logger.LogInformation("Refresh 成功: {ClientId}", clientId);
                    }
                    else
                    {
                        _logger.LogWarning("RefreshToken 失败，尝试重新登录");
                        refreshed = await GetDaHToken();
                    }
                }
                else
                {
                    refreshed = await GetDaHToken();
                }
                if (refreshed != null && refreshed.AccessToken != "")
                {
                    // 更新缓存
                    TokenCache.TokenMap[clientId] = refreshed;
                }

                return refreshed;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "获取 token 异常：{ClientId}", clientId);
                return new TokenEntry
                {
                    AccessToken = string.Empty,
                    ExpireAt = DateTimeOffset.UtcNow.AddMinutes(1)
                };
            }
        }

        private async Task<TokenEntry> GetDaHToken()
        {
            //1. 获取公钥
            DaHApiResult<PublicKeyDto> publicKeyResult = await GetPublicKey();
            if (publicKeyResult.Success == false)
            {
                return new TokenEntry
                {
                    AccessToken = string.Empty,
                    ExpireAt = DateTimeOffset.UtcNow.AddMinutes(1)
                };
            }
            LoginRequestDto dto = new();
            //2. 鉴权
            dto.PublicKey = publicKeyResult.Data!.PublicKey;
            dto.ClientId = _configuration["DahuaAuth:ClientId"]!;
            dto.ClientSecret = _configuration["DahuaAuth:ClientSecret"]!;
            dto.Password = _configuration["DahuaAuth:Password"]!;
            dto.Username = _configuration["DahuaAuth:Username"]!;

            DaHApiResult<LoginResDto> loginResult = await GetToken(dto);

            TokenEntry refreshed = new()
            {
                AccessToken = loginResult.Data!.AccessToken,
                ExpireAt = DateTimeOffset.UtcNow.AddSeconds(120)
            };
            return refreshed;
        }

        /// <summary>
        /// 刷新token，2个小时过期的
        /// </summary>
        /// <param name="dto"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        /// <exception cref="ArgumentException"></exception>
        /// <exception cref="InvalidOperationException"></exception>
        private async Task<DaHApiResult<TokenResDto>> RefreshToken(RefreshTokenReqDto dto)
        {
            DaHApiResult<TokenResDto> result = new DaHApiResult<TokenResDto>() { Success = true, Code = "0" };

            if (string.IsNullOrWhiteSpace(dto.RefreshToken))
            {
                result.Success = false;
                result.Code = "1005";
                result.Msg = "刷新令牌不能为空";
                _logger.LogWarning("刷新大华令牌失败，刷新令牌不能为空");
                return result;
            }

            try
            {
                var url = $"https://{_configuration["DahuaAuth:Host"]}/evo-apigw/evo-oauth/1.0.0/oauth/extend/refresh/token";

                using var resp = await _http.PostAsJsonAsync(url, dto);
                resp.EnsureSuccessStatusCode();

                result = await resp.Content.ReadFromJsonAsync<DaHApiResult<TokenResDto>>();

                if (!result.Success || result.Code != "0")
                {
                    result.Success = false;
                    result.Code = "1006";
                    result.Msg = "刷新大华令牌失败";
                    _logger.LogWarning("刷新大华令牌失败，返回结果：{Result}", result);
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "刷新大华令牌出错");
                result.Success = false;
                result.Code = "1006";
                result.Msg = "刷新大华令牌失败";
            }
            return result;
        }

        /// <summary>
        /// 获取公钥
        /// </summary>
        /// <returns></returns>
        /// <exception cref="NotImplementedException"></exception>
        private async Task<DaHApiResult<PublicKeyDto>> GetPublicKey()
        {
            DaHApiResult<PublicKeyDto> result = new() { Success = true, Code = "0", Data = new PublicKeyDto() { PublicKey = "" } };
            try
            {
                var url = $"https://{_configuration["DahuaAuth:Host"]}/evo-apigw/evo-oauth/1.0.0/oauth/public-key";

                using var resp = await _http.GetAsync(url);
                resp.EnsureSuccessStatusCode();
                var json = await resp.Content.ReadAsStringAsync();
                var envelope = JsonSerializer.Deserialize<DaHApiResult<PublicKeyDto>>(json, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });

                if (envelope?.Data?.PublicKey is null or { Length: 0 })
                {
                    _logger.LogWarning("获取大华公钥失败，返回结果：{Result}", json);
                    result.Success = false;
                    result.Code = "1001";
                    result.Msg = "获取大华公钥失败";

                    return result;
                }

                result.Data.PublicKey = envelope.Data.PublicKey;
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "大华平台获取公钥出错");
                result.Success = false;
                result.Code = "1001";
                result.Msg = "获取大华公钥失败";
            }
            return result;
        }

        /// <summary>
        /// 获取token
        /// </summary>
        /// <param name="dto"></param>
        /// <returns></returns>
        private async Task<DaHApiResult<LoginResDto>> GetToken(LoginRequestDto dto)
        {
            DaHApiResult<LoginResDto> result = new() { Success = true, Code = "0", Data = new LoginResDto { } };
            if (dto is null)
            {
                result.Success = false;

                result.Code = "1002";
                result.Msg = "请求参数不能为空";
                _logger.LogWarning("获取大华登录令牌失败，参数不能为空");
                return result;
            }
            if (string.IsNullOrWhiteSpace(dto.Password))
            {
                result.Success = false;
                result.Code = "1003";
                result.Msg = "密码不能为空";
                _logger.LogWarning("获取大华登录令牌失败，密码不能为空");
                return result;
            }
            try
            {
                var url = $"https://{_configuration["DahuaAuth:Host"]}/evo-apigw/evo-oauth/1.0.0/oauth/extend/token";
                //必须加密
                dto.Password = EncryptByPublicKey(dto.Password, dto.PublicKey!);
                using var resp = await _http.PostAsJsonAsync(url, dto);
                resp.EnsureSuccessStatusCode();

                var tokenInfo = await resp.Content.ReadFromJsonAsync<DaHApiResult<LoginResDto>>();

                if (tokenInfo == null || !result.Success || result.Code != "0")
                {
                    result.Success = false;
                    result.Code = "1004";
                    result.Msg = "获取大华登录令牌失败";
                    _logger.LogWarning("获取大华登录令牌失败，返回结果：{Result}", result);
                }
                result = tokenInfo!;
                //固定的拼接方式
                result.Data!.AccessToken = string.Concat(tokenInfo?.Data!.TokenType, " ", tokenInfo?.Data!.AccessToken);

                TokenEntry refreshed = new TokenEntry
                {
                    AccessToken = string.Concat(result!.Data.TokenType, " ", result.Data.AccessToken),

                    ExpireAt = DateTimeOffset.UtcNow.AddSeconds(result.Data.ExpiresIn)
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "获取大华登录令牌出错");
                result.Success = false;
                result.Code = "1004";
                result.Msg = "获取大华登录令牌失败";
            }
            return result;
        }

        /// <summary>
        /// 判断token是否有效
        /// </summary>
        /// <param name="token"></param>
        /// <returns></returns>
        public bool IsTokenValid(string token)
        {
            // 避免 NullReferenceException
            if (string.IsNullOrWhiteSpace(token))
                return true;

            // 统一写法，后续改条件只改这里
            return token.Length < 10;
        }

        #region RES加密

        private static string EncryptByPublicKey(string context, string publicKey)
        {
            RSACryptoServiceProvider rsa = new();

            rsa.ImportParameters(FromXmlStringExtensions(ConvertToXmlPublicJavaKey(publicKey)));
            byte[] byteText = System.Text.Encoding.UTF8.GetBytes(context);
            byte[] byteEntry = rsa.Encrypt(byteText, false);
            return Convert.ToBase64String(byteEntry);
        }

        private static RSAParameters FromXmlStringExtensions(string xmlString)
        {
            RSAParameters parameters = new RSAParameters();

            System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
            xmlDoc.LoadXml(xmlString);

            if (xmlDoc.DocumentElement!.Name.Equals("RSAKeyValue"))
            {
                foreach (System.Xml.XmlNode node in xmlDoc.DocumentElement.ChildNodes)
                {
                    switch (node.Name)
                    {
                        case "Modulus": parameters.Modulus = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "Exponent": parameters.Exponent = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "P": parameters.P = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "Q": parameters.Q = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "DP": parameters.DP = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "DQ": parameters.DQ = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "InverseQ": parameters.InverseQ = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                        case "D": parameters.D = string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText); break;
                    }
                }
            }
            else
            {
                throw new Exception("Invalid XML RSA key.");
            }

            return parameters;
        }

        private static string ConvertToXmlPublicJavaKey(string publicJavaKey)
        {
            RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicJavaKey));
            string xmlpublicKey = string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
              Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
              Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));
            Console.WriteLine(xmlpublicKey);
            return xmlpublicKey;
        }

        #endregion RES加密
    }
}