using Microsoft.Extensions.Logging;
using SKIT.FlurlHttpClient.Wechat.TenpayV3;
using SKIT.FlurlHttpClient.Wechat.TenpayV3.Models;
using YD_Event.Core.Entities;
using YD_Event.Core.Infrastructure.WeChat.Dto;
using Furion.DependencyInjection;
using Microsoft.AspNetCore.Hosting;
using System.Net.Http;
using Microsoft.Extensions.Hosting;

namespace YD_Event.Core.Infrastructure.WeChat;

/// <summary>
/// 微信支付服务
/// </summary>
/// <remarks>
/// 提供微信支付相关的核心功能，包括：
/// 1. JSAPI支付下单
/// 2. Native支付下单
/// 3. 订单状态查询
/// 4. 退款申请
/// 5. 退款查询
/// 6. 支付通知验证和解密
/// 7. 退款通知验证和解密
/// </remarks>
public class WeChatPayService : ITransient
{
    private readonly ILogger<WeChatPayService> _logger;
    private readonly IWebHostEnvironment _webHostEnvironment;
    private readonly IHttpClientFactory _httpClientFactory;
    private const int DefaultNetworkTimeoutSeconds = 30;

    public WeChatPayService(ILogger<WeChatPayService> logger, IWebHostEnvironment webHostEnvironment, IHttpClientFactory httpClientFactory)
    {
        _logger = logger;
        _webHostEnvironment = webHostEnvironment;
        _httpClientFactory = httpClientFactory ?? throw new ArgumentNullException(nameof(httpClientFactory));
    }

    /// <summary>
    /// 创建微信支付客户端
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <returns>微信支付客户端实例</returns>
    private async Task<WechatTenpayClient> CreateClientAsync(WeChatPayConfig config)
    {
        var privateKey = await GetPrivateKeyAsync(config.MerchantCertificatePrivateKey);
        if (string.IsNullOrWhiteSpace(privateKey))
        {
            throw new InvalidOperationException("无法获取微信支付商户私钥，请检查配置。");
        }

        var options = new WechatTenpayClientOptions()
        {
            MerchantId = config.MerchantIdValue,
            MerchantV3Secret = config.MerchantV3Secret,
            MerchantCertificateSerialNumber = config.MerchantCertificateSerialNumber,
            MerchantCertificatePrivateKey = privateKey
        };
        return new WechatTenpayClient(options);
    }

    /// <summary>
    /// 获取微信支付商户私钥
    /// </summary>
    /// <param name="source">私钥来源，可以是：直接的密钥内容、本地文件路径、网络URL</param>
    /// <returns>私钥内容字符串</returns>
    private async Task<string> GetPrivateKeyAsync(string source)
    {
        if (string.IsNullOrWhiteSpace(source))
        {
            _logger.LogError("私钥来源为空");
            throw new ArgumentException("私钥来源不能为空", nameof(source));
        }

        try
        {
            var trimmedSource = source.Trim();
            
            if (IsPrivateKeyContent(trimmedSource))
            {
                _logger.LogDebug("使用直接提供的私钥内容");
                return trimmedSource;
            }

            if (Uri.TryCreate(trimmedSource, UriKind.Absolute, out var uri))
            {
                if (uri.IsFile)
                {
                    _logger.LogDebug("从本地文件路径加载私钥: {Path}", uri.LocalPath);
                    return await ReadPrivateKeyFromFileAsync(uri.LocalPath);
                }
                else if (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps)
                {
                    _logger.LogDebug("从网络URL加载私钥: {Url}", trimmedSource);
                    return await ReadPrivateKeyFromNetworkAsync(trimmedSource);
                }
            }

            var localPath = Path.Combine(_webHostEnvironment.WebRootPath, trimmedSource.TrimStart('/', '\\'));
            if (File.Exists(localPath))
            {
                _logger.LogDebug("从 wwwroot 相对路径加载私钥: {Path}", localPath);
                return await ReadPrivateKeyFromFileAsync(localPath);
            }

            if (File.Exists(trimmedSource))
            {
                _logger.LogDebug("从绝对路径加载私钥: {Path}", trimmedSource);
                return await ReadPrivateKeyFromFileAsync(trimmedSource);
            }

            _logger.LogError("无法从任何来源加载私钥: {Source}", source);
            throw new FileNotFoundException($"无法找到私钥文件或解析私钥内容: {source}");
        }
        catch (Exception ex) when (ex is not ArgumentException && ex is not FileNotFoundException)
        {
            _logger.LogError(ex, "获取私钥过程中发生异常: {Source}", source);
            throw;
        }
    }

    /// <summary>
    /// 检查输入是否为有效的私钥内容
    /// </summary>
    private bool IsPrivateKeyContent(string content)
    {
        return content.StartsWith("-----BEGIN", StringComparison.OrdinalIgnoreCase) ||
               content.StartsWith("MII", StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>
    /// 从本地文件读取私钥
    /// </summary>
    private async Task<string> ReadPrivateKeyFromFileAsync(string filePath)
    {
        if (!File.Exists(filePath))
        {
            throw new FileNotFoundException($"私钥文件不存在: {filePath}");
        }

        var content = await File.ReadAllTextAsync(filePath);
        if (string.IsNullOrWhiteSpace(content))
        {
            throw new InvalidOperationException($"私钥文件内容为空: {filePath}");
        }

        _logger.LogInformation("成功从文件加载私钥: {Path}", filePath);
        return content;
    }

    /// <summary>
    /// 从网络URL读取私钥
    /// </summary>
    private async Task<string> ReadPrivateKeyFromNetworkAsync(string url)
    {
        var client = _httpClientFactory.CreateClient();
        client.Timeout = TimeSpan.FromSeconds(DefaultNetworkTimeoutSeconds);

        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(DefaultNetworkTimeoutSeconds + 5));
        
        try
        {
            var response = await client.GetAsync(url, cts.Token);
            response.EnsureSuccessStatusCode();

            var content = await response.Content.ReadAsStringAsync(cts.Token);
            if (string.IsNullOrWhiteSpace(content))
            {
                throw new InvalidOperationException($"从网络获取的私钥内容为空: {url}");
            }

            _logger.LogInformation("成功从网络加载私钥: {Url}", url);
            return content;
        }
        catch (HttpRequestException ex)
        {
            _logger.LogError(ex, "网络请求失败，无法获取私钥: {Url}", url);
            throw new InvalidOperationException($"网络请求失败，无法获取私钥: {url}", ex);
        }
        catch (OperationCanceledException ex)
        {
            _logger.LogError(ex, "获取私钥请求超时: {Url}", url);
            throw new TimeoutException($"获取私钥请求超时: {url}", ex);
        }
    }

    /// <summary>
    /// 创建 JSAPI 支付
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="request">JSAPI 支付请求参数</param>
    /// <returns>支付结果，包含 prepay_id 和支付参数</returns>
    /// <remarks>
    /// JSAPI 支付适用于小程序、公众号等场景，需要用户的 OpenId
    /// </remarks>
    public async Task<WeChatPayResult> CreateJsApiPayAsync(WeChatPayConfig config, CreateJsApiPayRequest request)
    {
        try
        {
            var client = await CreateClientAsync(config);
            var tenpayRequest = new CreatePayTransactionJsapiRequest()
            {
                OutTradeNumber = request.OutTradeNo,
                AppId = request.AppId,
                Description = request.Description,
                NotifyUrl = request.NotifyUrl,
                Amount = new CreatePayTransactionJsapiRequest.Types.Amount()
                {
                    Total = request.TotalAmount,
                    Currency = request.Currency
                },
                Payer = new CreatePayTransactionJsapiRequest.Types.Payer()
                {
                    OpenId = request.OpenId
                }
            };

            if (request.ExpireTime.HasValue)
            {
                tenpayRequest.ExpireTime = request.ExpireTime.Value;
            }

            var response = await client.ExecuteCreatePayTransactionJsapiAsync(tenpayRequest);
            if (response.IsSuccessful())
            {
                var result = new WeChatPayResult
                {
                    Success = true,
                    TradeType = "JSAPI",
                    PrepayId = response.PrepayId
                };

                var parameters = client.GenerateParametersForJsapiPayRequest(request.AppId, response.PrepayId);
                result.JsApiParameters = new JsApiPayParameters
                {
                    AppId = parameters["appId"],
                    TimeStamp = parameters["timeStamp"],
                    NonceStr = parameters["nonceStr"],
                    Package = parameters["package"],
                    SignType = parameters["signType"],
                    PaySign = parameters["paySign"]
                };

                return result;
            }
            else
            {
                _logger.LogError($"微信 JSAPI 支付下单失败: {response.ErrorMessage}");
                return new WeChatPayResult
                {
                    Success = false,
                    Message = response.ErrorMessage
                };
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "微信 JSAPI 支付下单异常");
            return new WeChatPayResult
            {
                Success = false,
                Message = ex.Message
            };
        }
    }

    /// <summary>
    /// 创建 Native 支付
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="request">Native 支付请求参数</param>
    /// <returns>支付结果，包含二维码链接</returns>
    /// <remarks>
    /// Native 支付适用于生成二维码供用户扫描支付的场景
    /// </remarks>
    public async Task<WeChatPayResult> CreateNativePayAsync(WeChatPayConfig config, CreateNativePayRequest request)
    {
        try
        {
            var client = await CreateClientAsync(config);
            var tenpayRequest = new CreatePayTransactionNativeRequest()
            {
                OutTradeNumber = request.OutTradeNo,
                AppId = request.AppId,
                Description = request.Description,
                NotifyUrl = request.NotifyUrl,
                Amount = new CreatePayTransactionNativeRequest.Types.Amount()
                {
                    Total = request.TotalAmount,
                    Currency = request.Currency
                }
            };

            if (request.ExpireTime.HasValue)
            {
                tenpayRequest.ExpireTime = request.ExpireTime.Value;
            }

            var response = await client.ExecuteCreatePayTransactionNativeAsync(tenpayRequest);
            if (response.IsSuccessful())
            {
                return new WeChatPayResult
                {
                    Success = true,
                    TradeType = "NATIVE",
                    CodeUrl = response.QrcodeUrl,
                    QrcodeUrl = response.QrcodeUrl
                };
            }
            else
            {
                _logger.LogError($"微信 Native 支付下单失败: {response.ErrorMessage}");
                return new WeChatPayResult
                {
                    Success = false,
                    Message = response.ErrorMessage
                };
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "微信 Native 支付下单异常");
            return new WeChatPayResult
            {
                Success = false,
                Message = ex.Message
            };
        }
    }

    /// <summary>
    /// 查询订单状态
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="outTradeNo">商户订单号</param>
    /// <returns>订单查询结果</returns>
    /// <remarks>
    /// 根据商户订单号查询微信支付订单的状态
    /// </remarks>
    public async Task<WeChatPayQueryResult> QueryOrderAsync(WeChatPayConfig config, string outTradeNo)
    {
        try
        {
            var client = await CreateClientAsync(config);
            var request = new GetPayTransactionByOutTradeNumberRequest()
            {
                OutTradeNumber = outTradeNo,
                MerchantId = config.MerchantIdValue
            };

            var response = await client.ExecuteGetPayTransactionByOutTradeNumberAsync(request);
            if (response.IsSuccessful())
            {
                return new WeChatPayQueryResult
                {
                    Success = true,
                    TradeState = response.TradeState,
                    TradeStateDesc = response.TradeStateDescription,
                    TransactionId = response.TransactionId,
                    OutTradeNo = response.OutTradeNumber,
                    TotalAmount = response.Amount?.Total,
                    PayerAmount = response.Amount?.PayerTotal,
                    SuccessTime = response.SuccessTime
                };
            }
            else
            {
                _logger.LogError($"查询订单失败: {response.ErrorMessage}");
                return new WeChatPayQueryResult
                {
                    Success = false,
                    Message = response.ErrorMessage
                };
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "查询订单异常");
            return new WeChatPayQueryResult
            {
                Success = false,
                Message = ex.Message
            };
        }
    }

    /// <summary>
    /// 创建退款申请
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="request">退款请求参数</param>
    /// <returns>退款结果</returns>
    /// <remarks>
    /// 提交退款申请，当前为模拟实现，需根据实际微信支付SDK完善
    /// </remarks>
    public async Task<WeChatRefundResult> CreateRefundAsync(WeChatPayConfig config, CreateRefundRequest request)
    {
        try
        {
            _logger.LogInformation($"微信退款申请: 商户单号={request.OutTradeNo}, 退款单号={request.OutRefundNo}, 退款金额={request.RefundAmount}");
            
            // 模拟退款成功（实际项目中需要调用微信支付SDK）
            return await Task.FromResult(new WeChatRefundResult
            {
                Success = true,
                RefundId = Guid.NewGuid().ToString("N"),
                OutRefundNo = request.OutRefundNo,
                OutTradeNo = request.OutTradeNo,
                RefundStatus = "SUCCESS",
                Message = "退款申请已提交"
            });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "微信退款申请异常");
            return new WeChatRefundResult
            {
                Success = false,
                Message = ex.Message
            };
        }
    }

    /// <summary>
    /// 查询退款状态
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="outRefundNo">商户退款单号</param>
    /// <returns>退款查询结果</returns>
    /// <remarks>
    /// 根据商户退款单号查询退款状态，当前为模拟实现
    /// </remarks>
    public async Task<WeChatRefundQueryResult> QueryRefundAsync(WeChatPayConfig config, string outRefundNo)
    {
        try
        {
            _logger.LogInformation($"查询微信退款: 退款单号={outRefundNo}");
            
            // 模拟退款查询（实际项目中需要调用微信支付SDK）
            return await Task.FromResult(new WeChatRefundQueryResult
            {
                Success = true,
                RefundId = outRefundNo,
                OutRefundNo = outRefundNo,
                RefundStatus = "SUCCESS",
                Message = "退款已完成"
            });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "查询退款异常");
            return new WeChatRefundQueryResult
            {
                Success = false,
                Message = ex.Message
            };
        }
    }

    /// <summary>
    /// 验证支付通知签名
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="notifyRequest">支付通知请求参数</param>
    /// <returns>签名是否有效</returns>
    /// <remarks>
    /// 验证微信支付通知的签名是否有效
    /// </remarks>
    public async Task<bool> VerifyPayNotifyAsync(WeChatPayConfig config, WeChatPayNotifyRequest notifyRequest)
    {
        try
        {
            var client = await CreateClientAsync(config);
            bool valid = client.VerifyEventSignature(
                notifyRequest.Timestamp,
                notifyRequest.Nonce,
                notifyRequest.Body,
                notifyRequest.Signature,
                notifyRequest.SerialNumber
            );
            return await Task.FromResult(valid);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "验证支付通知签名异常");
            return false;
        }
    }

    /// <summary>
    /// 验证退款通知签名
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="notifyRequest">退款通知请求参数</param>
    /// <returns>签名是否有效</returns>
    /// <remarks>
    /// 验证微信退款通知的签名是否有效
    /// </remarks>
    public async Task<bool> VerifyRefundNotifyAsync(WeChatPayConfig config, WeChatRefundNotifyRequest notifyRequest)
    {
        try
        {
            var client = await CreateClientAsync(config);
            bool valid = client.VerifyEventSignature(
                notifyRequest.Timestamp,
                notifyRequest.Nonce,
                notifyRequest.Body,
                notifyRequest.Signature,
                notifyRequest.SerialNumber
            );
            return await Task.FromResult(valid);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "验证退款通知签名异常");
            return false;
        }
    }

    /// <summary>
    /// 解密支付通知数据
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="notifyRequest">支付通知请求参数</param>
    /// <returns>解密后的支付通知数据，失败返回 null</returns>
    /// <remarks>
    /// 解密微信支付通知的加密数据，仅处理 TRANSACTION.SUCCESS 事件
    /// </remarks>
    public async Task<WeChatPayNotifyData?> DecryptPayNotifyDataAsync(WeChatPayConfig config, WeChatPayNotifyRequest notifyRequest)
    {
        try
        {
            var client = await CreateClientAsync(config);
            var callbackModel = client.DeserializeEvent(notifyRequest.Body);
            if (callbackModel.EventType == "TRANSACTION.SUCCESS")
            {
                var eventData = client.DecryptEventResource<SKIT.FlurlHttpClient.Wechat.TenpayV3.Events.TransactionResource>(callbackModel);
                return new WeChatPayNotifyData
                {
                    EventType = callbackModel.EventType,
                    OutTradeNo = eventData.OutTradeNumber,
                    TransactionId = eventData.TransactionId,
                    TradeState = eventData.TradeState,
                    TotalAmount = eventData.Amount?.Total,
                    PayerAmount = eventData.Amount?.PayerTotal,
                    SuccessTime = eventData.SuccessTime
                };
            }
            return null;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "解密支付通知数据异常");
            return null;
        }
    }

    /// <summary>
    /// 解密退款通知数据
    /// </summary>
    /// <param name="config">微信支付配置信息</param>
    /// <param name="notifyRequest">退款通知请求参数</param>
    /// <returns>解密后的退款通知数据，失败返回 null</returns>
    /// <remarks>
    /// 解密微信退款通知的加密数据，处理 REFUND.SUCCESS、REFUND.ABNORMAL、REFUND.CLOSED 事件
    /// </remarks>
    public async Task<WeChatRefundNotifyData?> DecryptRefundNotifyDataAsync(WeChatPayConfig config, WeChatRefundNotifyRequest notifyRequest)
    {
        try
        {
            var client = await CreateClientAsync(config);
            var callbackModel = client.DeserializeEvent(notifyRequest.Body);
            if (callbackModel.EventType == "REFUND.SUCCESS" || callbackModel.EventType == "REFUND.ABNORMAL" || callbackModel.EventType == "REFUND.CLOSED")
            {
                var eventData = client.DecryptEventResource<SKIT.FlurlHttpClient.Wechat.TenpayV3.Events.RefundResource>(callbackModel);
                return new WeChatRefundNotifyData
                {
                    EventType = callbackModel.EventType,
                    OutTradeNo = eventData.OutTradeNumber,
                    OutRefundNo = eventData.OutRefundNumber,
                    RefundId = eventData.RefundId,
                    RefundStatus = eventData.RefundStatus,
                    RefundAmount = eventData.Amount?.Refund,
                    PayerRefundAmount = eventData.Amount?.PayerRefund,
                    SuccessTime = eventData.SuccessTime
                };
            }
            return null;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "解密退款通知数据异常");
            return null;
        }
    }
}