package wechat

import (
	"context"

	refundRequest "github.com/ArtisanCloud/PowerWeChat/v3/src/payment/refund/request"
	refundResponse "github.com/ArtisanCloud/PowerWeChat/v3/src/payment/refund/response"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"go.uber.org/zap"
)

// 微信支付 v3 退款单状态（渠道 status 字段原文）
const (
	// refundStatusSuccess 退款成功
	refundStatusSuccess = "SUCCESS"
	// refundStatusClosed 退款关闭
	refundStatusClosed = "CLOSED"
	// refundStatusProcessing 退款处理中
	refundStatusProcessing = "PROCESSING"
	// refundStatusAbnormal 退款异常
	refundStatusAbnormal = "ABNORMAL"
)

// RefundOrderRequest 微信支付 v3 原路退款请求
//
// 金额单位均为分，且均为整型直传渠道；本结构不包含任何通知地址字段，
// 退款进度由调用方通过 QueryRefund 主动查询获得。
type RefundOrderRequest struct {
	// OutTradeNo 商户订单号（原支付单号）
	OutTradeNo string `json:"out_trade_no"`
	// OutRefundNo 商户退款单号
	OutRefundNo string `json:"out_refund_no"`
	// Amount 原订单金额，单位分
	Amount int64 `json:"amount"`
	// Refund 本次退款金额，单位分
	Refund int64 `json:"refund"`
	// Reason 退款原因，可选
	Reason string `json:"reason"`
	// Currency 退款币种，可选，为空时使用默认值 CNY
	Currency string `json:"currency"`
}

// RefundOrderResult 微信支付 v3 退款结果
type RefundOrderResult struct {
	// Success 是否退款成功，仅当渠道状态为 SUCCESS 时为 true
	Success bool `json:"success"`
	// RefundID 微信支付退款单号
	RefundID string `json:"refund_id"`
	// OutRefundNo 商户退款单号
	OutRefundNo string `json:"out_refund_no"`
	// OutTradeNo 商户订单号
	OutTradeNo string `json:"out_trade_no"`
	// TransactionID 微信支付订单号
	TransactionID string `json:"transaction_id"`
	// Status 渠道退款状态原文：SUCCESS/CLOSED/PROCESSING/ABNORMAL
	Status string `json:"status"`
	// RefundFee 退款金额，单位分
	RefundFee int64 `json:"refund_fee"`
	// ChannelCode 渠道业务错误码，仅在渠道返回错误响应体时非空
	ChannelCode string `json:"channel_code"`
	// Message 状态说明
	Message string `json:"message"`
}

// RefundOrder 发起微信支付 v3 原路退款
//
// 不向渠道传递任何通知地址（notify_url 留空，接口调用时该字段不会出现在请求体中），
// 退款结果以本次返回的 Status 为准，异步进度由调用方通过 QueryRefund 查询。
func (s *PaymentService) RefundOrder(ctx context.Context, req RefundOrderRequest) (*RefundOrderResult, error) {
	if req.OutTradeNo == "" || req.OutRefundNo == "" {
		return nil, errors.New(errors.CodeInvalidParam, "商户订单号和商户退款单号不能为空")
	}
	if req.Amount <= 0 || req.Refund <= 0 {
		return nil, errors.New(errors.CodeInvalidParam, "原订单金额和退款金额必须大于 0")
	}
	if req.Refund > req.Amount {
		return nil, errors.New(errors.CodeInvalidParam, "退款金额不能大于原订单金额")
	}

	currency := req.Currency
	if currency == "" {
		currency = "CNY"
	}

	resp, err := s.app.Refund.Refund(ctx, &refundRequest.RequestRefund{
		OutTradeNo:  req.OutTradeNo,
		OutRefundNo: req.OutRefundNo,
		Reason:      req.Reason,
		Amount: &refundRequest.RefundAmount{
			Refund:   int(req.Refund),
			Total:    int(req.Amount),
			Currency: currency,
		},
	})
	if err != nil {
		s.logger.Error("发起微信退款失败",
			zap.String("out_trade_no", req.OutTradeNo),
			zap.String("out_refund_no", req.OutRefundNo),
			zap.Int64("refund", req.Refund),
			zap.Error(err),
		)
		return nil, errors.Wrap(errors.CodeWechatPayFailed, err)
	}
	if resp == nil {
		s.logger.Error("发起微信退款失败：空响应",
			zap.String("out_trade_no", req.OutTradeNo),
			zap.String("out_refund_no", req.OutRefundNo),
		)
		return nil, errors.New(errors.CodeWechatPayFailed, "微信退款失败：渠道返回空响应")
	}

	result := mapRefundResult(resp)
	if result.Success {
		s.logger.Info("发起微信退款成功",
			zap.String("out_trade_no", req.OutTradeNo),
			zap.String("out_refund_no", req.OutRefundNo),
			zap.String("refund_id", result.RefundID),
			zap.String("status", result.Status),
		)
	} else {
		s.logger.Warn("发起微信退款未成功",
			zap.String("out_trade_no", req.OutTradeNo),
			zap.String("out_refund_no", req.OutRefundNo),
			zap.String("status", result.Status),
			zap.String("channel_code", result.ChannelCode),
			zap.String("message", result.Message),
		)
	}

	return result, nil
}

// QueryRefund 查询微信支付 v3 退款单
//
// 状态与金额映射规则与 RefundOrder 一致。
func (s *PaymentService) QueryRefund(ctx context.Context, outRefundNo string) (*RefundOrderResult, error) {
	if outRefundNo == "" {
		return nil, errors.New(errors.CodeInvalidParam, "商户退款单号不能为空")
	}

	resp, err := s.app.Refund.Query(ctx, outRefundNo)
	if err != nil {
		s.logger.Error("查询微信退款失败",
			zap.String("out_refund_no", outRefundNo),
			zap.Error(err),
		)
		return nil, errors.Wrap(errors.CodeWechatPayFailed, err)
	}
	if resp == nil {
		s.logger.Error("查询微信退款失败：空响应", zap.String("out_refund_no", outRefundNo))
		return nil, errors.New(errors.CodeWechatPayFailed, "查询微信退款失败：渠道返回空响应")
	}

	result := mapRefundResult(resp)
	s.logger.Debug("查询微信退款完成",
		zap.String("out_refund_no", outRefundNo),
		zap.String("refund_id", result.RefundID),
		zap.String("status", result.Status),
		zap.String("channel_code", result.ChannelCode),
	)

	return result, nil
}

// mapRefundResult 将微信退款接口响应映射为统一结果
//
// 渠道 status 为 SUCCESS 时 Success 为 true；CLOSED/ABNORMAL/PROCESSING 等明确状态
// 返回结果且不报错，由调用方按 Status 与 Message 处理。
// 渠道返回业务错误码（响应体含 code，通常为 4xx，退款单未被受理）同样返回结果，
// 由调用方按 ChannelCode 判定；只有传输或解析失败才在调用处作为 error 返回——
// 这样调用方才能把「渠道明确表态」与「结果未知」区分开。
func mapRefundResult(resp *refundResponse.ResponseRefund) *RefundOrderResult {
	if resp.Code != "" {
		return &RefundOrderResult{
			OutRefundNo: resp.OutRefundNO,
			OutTradeNo:  resp.OutTradeNO,
			ChannelCode: resp.Code,
			Message:     "微信退款失败：" + resp.Code + " " + resp.Message,
		}
	}

	result := &RefundOrderResult{
		RefundID:      resp.RefundID,
		OutRefundNo:   resp.OutRefundNO,
		OutTradeNo:    resp.OutTradeNO,
		TransactionID: resp.TransactionID,
		Status:        resp.Status,
	}
	if resp.Amount != nil {
		result.RefundFee = int64(resp.Amount.Refund)
	}

	result.Success = resp.Status == refundStatusSuccess
	result.Message = refundStatusMessage(resp.Status)

	return result
}

// refundStatusMessage 返回微信退款状态的说明文案
func refundStatusMessage(status string) string {
	switch status {
	case refundStatusSuccess:
		return "退款成功"
	case refundStatusClosed:
		return "退款已关闭"
	case refundStatusAbnormal:
		return "退款异常"
	case refundStatusProcessing:
		return "退款处理中"
	case "":
		return "退款状态未知，请稍后查询"
	default:
		return "退款状态：" + status
	}
}