using System.Text;
using System.Text.RegularExpressions;
using System.ComponentModel.DataAnnotations;
using System.Collections.Concurrent;
using System.Security.Cryptography;
using System.Text.Json;
using System.Net.Http.Json;
using ReZero.DependencyInjection;
using Newtonsoft.Json.Linq;
using Microsoft.Extensions.Logging;
using System.Threading.Tasks;
using medical.transfomer.business;

namespace medical.insu.transfomer
{
    /// <summary>
    /// 定义InsuranceRequest类，用于替代缺失的引用
    /// </summary>
    public class InsuranceRequest
    {
        public string MsgId { get; set; } = string.Empty;
        public string MdtrtareaAdmvs { get; set; } = string.Empty;
        public string RecerSysCode { get; set; } = string.Empty;
        public string Infver { get; set; } = string.Empty;
        public int OpterType { get; set; }
        public string Opter { get; set; } = string.Empty;
        public string OpterName { get; set; } = string.Empty;
        public DateTime InfTime { get; set; }
        public string FixmedinsCode { get; set; } = string.Empty;
        public string FixmedinsName { get; set; } = string.Empty;
        public string Input { get; set; } = string.Empty;
        public string InsuplcAdmdvs { get; set; } = string.Empty;
        public string Signtype { get; set; } = string.Empty;
        public string Infno { get; set; } = string.Empty;
    }

    /// <summary>
    /// 定义ResponseHeader类，用于替代缺失的引用
    /// </summary>
    public class ResponseHeader
    {
        public string Version { get; set; } = string.Empty;
        public string SenderCode { get; set; } = string.Empty;
        public string ReceiverCode { get; set; } = string.Empty;
        public string MsgId { get; set; } = string.Empty;
        public string InfTime { get; set; } = string.Empty;
        public string ResultCode { get; set; } = string.Empty;
        public string ResultMsg { get; set; } = string.Empty;
        public string SignatureAlgorithm { get; set; } = string.Empty;
        public string EncryptionAlgorithm { get; set; } = string.Empty;
    }

    /// <summary>
    /// 定义Response类，用于替代缺失的引用
    /// </summary>
    public class Response
    {
        public ResponseHeader Header { get; set; } = new ResponseHeader();
        public string Body { get; set; } = string.Empty;
        public string Signature { get; set; } = string.Empty;
    }

    /// <summary>
    /// 业务服务接口
    /// </summary>
    public interface IInsuranceBusinessService
    {
        object Execute(InsuranceRequest request);
    }

    public class MedicalInsuranceService: IScopeContract
    {
        private readonly ConcurrentDictionary<string, IInsuranceBusinessService> _serviceCache = new();
        private readonly TransformerFactory _transformerFactory;
        private readonly ILogger<MedicalInsuranceService> _logger;

        public MedicalInsuranceService(
            TransformerFactory transformerFactory,
            ILogger<MedicalInsuranceService> logger)
        {
            _transformerFactory = transformerFactory;
            _logger = logger;
        }

        /// <summary>
        /// 处理医保交易请求
        /// </summary>
        /// <param name="action">操作类型</param>
        /// <param name="data">交易数据</param>
        /// <returns>处理结果</returns>
        public async Task<object> ProcessMedicalInsurance(string action, JObject data)
        {
            try
            {
                _logger.LogInformation($"开始处理医保交易请求: {action}");
                
                // 使用转换工厂执行医保交易
                var result = await _transformerFactory.ExecuteMethod(action, data);
                
                _logger.LogInformation($"医保交易请求处理完成: {action}");
                return result;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"处理医保交易请求异常: {action}");
                return new { code = -1, msg = $"处理请求异常: {ex.Message}" };
            }
        }

        public void ValidateRequest(InsuranceRequest request)
        {
            if (string.IsNullOrEmpty(request.MsgId))
                throw new ValidationException("报文ID不能为空");

            if (string.IsNullOrEmpty(request.MdtrtareaAdmvs))
                throw new ValidationException("就医地医保区划不能为空");

            if (string.IsNullOrEmpty(request.RecerSysCode))
                throw new ValidationException("接收方系统代码不能为空");

            if (string.IsNullOrEmpty(request.Infver))
                throw new ValidationException("接口版本号不能为空");
            if (string.IsNullOrEmpty(request.OpterType.ToString()))
                throw new ValidationException("经办人类别不能为空");
            if (string.IsNullOrEmpty(request.Opter))
                throw new ValidationException("经办人不能为空");

            if (string.IsNullOrEmpty(request.OpterName))
                throw new ValidationException("经办人姓名不能为空");

            // 假设 request.InfTime 现在是 DateTime 类型，将其转换为字符串进行判断
            if (string.IsNullOrEmpty(request.InfTime.ToString("yyyyMMddHHmmss")))
                throw new ValidationException("交易时间不能为空");
            if (string.IsNullOrEmpty(request.FixmedinsCode))
                throw new ValidationException("定点医药机构编号不能为空");

            if (string.IsNullOrEmpty(request.FixmedinsName))
                throw new ValidationException("定点医药机构名称不能为空");
        }

        public IInsuranceBusinessService GetServiceByInfoNo(string infoNo)
        {
            return _serviceCache.GetOrAdd(infoNo, key => key switch
            {
                // "1101" => new PersonInfoService(),
                // "2101" => new RegistrationService(),
                // "2201" => new PreSettlementService(),
                // _ => throw new BusinessException($"未知的交易编号: {key}")
                _ => null
            });
        }

        /// <summary>
        /// 入口方法
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        public Response ProcessRequest(InsuranceRequest request)
        {
            ValidateRequest(request);
            ValidateParameterFormat(request);
            VerifySignature(request);

            var service = GetServiceByInfoNo(request.Infno);
            if (service == null)
            {
                throw new InvalidOperationException($"未找到处理服务: {request.Infno}");
            }
            
            var result = service.Execute(request);

            return new Response
            {
                Header = GenerateResponseHeader(request),
                Body = EncryptData(result),
                Signature = GenerateSignature(result)
            };
        }

        /// <summary>
        /// 新增参数格式验证
        /// </summary>
        /// <param name="request"></param>
        /// <exception cref="ValidationException"></exception>
        public static void ValidateParameterFormat(InsuranceRequest request)
        {
            // 增强msgid格式校验
            if (!Regex.IsMatch(request.MsgId, @"^\d{12}\d{14}\d{4}$"))
                throw new ValidationException("报文ID格式必须为12位机构编号+14位时间+4位流水号");

            // 条件必填验证
            if (!string.IsNullOrEmpty(request.Input) && string.IsNullOrEmpty(request.InsuplcAdmdvs))
                throw new ValidationException("当交易输入包含人员编号时，参保地医保区划为必填项");

            // 版本号格式校验
            if (!Regex.IsMatch(request.Infver, @"^V\d+\.\d+$"))
                throw new ValidationException("接口版本号格式应为VX.X");

            // 签名类型校验
            if (!string.IsNullOrEmpty(request.Signtype) && !new[] { "SM2", "SM3" }.Contains(request.Signtype))
                throw new ValidationException("签名类型只支持SM2/SM3");

            // 由于 request.InfTime 是 DateTime 类型，先将其转换为指定格式的字符串再进行正则匹配
            if (!Regex.IsMatch(request.InfTime.ToString("yyyyMMddHHmmss"), @"^\d{14}$"))
                throw new ValidationException("交易时间格式必须为yyyyMMddHHmmss");

            if (request.OpterName?.Length > 50)
                throw new ValidationException("经办人姓名不能超过50个字符");
        }

        /// <summary>
        /// 增强版响应头生成
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        public static ResponseHeader GenerateResponseHeader(InsuranceRequest request)
        {
            return new ResponseHeader
            {
                Version = "1.0",
                // 由于 _config 不存在，这里假设添加一个默认值，实际使用时需要根据业务逻辑修改
                SenderCode = "DefaultInstitutionCode",
                ReceiverCode = request.FixmedinsCode,
                MsgId = Guid.NewGuid().ToString("N").ToUpper(),
                InfTime = DateTime.Now.ToString("yyyyMMddHHmmss"),
                ResultCode = "1000",
                ResultMsg = "处理成功",
                SignatureAlgorithm = "HMAC-SHA256",
                EncryptionAlgorithm = "AES-256-GCM"
            };
        }

        /// <summary>
        /// 完整签名验证流程
        /// </summary>
        /// <param name="request"></param>
        /// <exception cref="InvalidOperationException"></exception>
        public static void VerifySignature(InsuranceRequest request)
        {
            var rawData = $"{request.MsgId}{request.InfTime}{request.FixmedinsCode}";


            var hmac = new HMACSHA256(Encoding.UTF8.GetBytes("DefaultSignKey"));
            var computedSignature = hmac.ComputeHash(Encoding.UTF8.GetBytes(rawData));

            // 由于 InsuranceRequest 未包含 Signature 的定义，这里假设添加一个默认空字符串处理
            if (!computedSignature.SequenceEqual(Convert.FromBase64String("")))
                // 由于 SecurityException 可能未找到，使用更通用的 InvalidOperationException 替代
                throw new InvalidOperationException("数字签名验证失败");
        }

        /// <summary>
        ///  医保系统通信模块
        /// </summary>
        /// <param name="endpoint"></param>
        /// <param name="payload"></param>
        /// <returns></returns>
        public async Task<Response> CallInsuranceSystem(string endpoint, object payload)
        {
            // 由于 _httpClientFactory 不存在，使用新创建的 HttpClient 实例替代
            using var client = new HttpClient();
            // 由于 _config 不存在，暂时使用一个默认的 API Key，实际使用时需根据业务逻辑修改
            client.DefaultRequestHeaders.Add("X-Medicare-API-Key", "DefaultApiKey");

            var content = new StringContent(
            // 引入 System.Text.Json 命名空间以使用 JsonSerializer

            System.Text.Json.JsonSerializer.Serialize(payload),
                Encoding.UTF8,
                "application/json");

            var response = await client.PostAsync(endpoint, content);
            response.EnsureSuccessStatusCode();

            return await response.Content.ReadFromJsonAsync<Response>();
        }

        public static string EncryptData(object data)
        {
            var json = JsonSerializer.Serialize(data);
            // 由于 AesUtility 不存在，使用 .NET 内置的 AES 加密实现


            // 定义一个临时的 AES 加密方法
            static string EncryptWithAes(string plainText, string key)
            {
                byte[] encrypted;
                using var aesAlg = Aes.Create();
                {
                    aesAlg.Key = Encoding.UTF8.GetBytes(key);
                    aesAlg.GenerateIV();

                    ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

                    using (MemoryStream msEncrypt = new MemoryStream())
                    {
                        using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                        {
                            using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                            {
                                swEncrypt.Write(plainText);
                            }
                            encrypted = msEncrypt.ToArray();
                        }
                    }

                    // 将 IV 和加密后的数据拼接，以方便后续解密
                    byte[] combinedIvCt = new byte[aesAlg.IV.Length + encrypted.Length];
                    Array.Copy(aesAlg.IV, 0, combinedIvCt, 0, aesAlg.IV.Length);
                    Array.Copy(encrypted, 0, combinedIvCt, aesAlg.IV.Length, encrypted.Length);

                    return Convert.ToBase64String(combinedIvCt);
                }
            }

            // 由于 _config 不存在，使用一个默认的加密密钥替代，实际使用时需根据业务逻辑修改
            return EncryptWithAes(json, "DefaultEncryptionKey");
        }

        public static string GenerateSignature(object data)
        {
            var json = JsonSerializer.Serialize(data);
            // 由于 HMACSHA256.HashData 没有单参数重载，需要创建 HMACSHA256 实例来计算哈希值
            using var hmac = new HMACSHA256();
            {
                byte[] hashBytes = hmac.ComputeHash(Encoding.UTF8.GetBytes(json));
                return Convert.ToBase64String(hashBytes);
            }
        }
    }
}