package payment

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"strconv"
	"strings"

	"hfb_sys/backend/internal/model"

	"go.uber.org/zap"
	"gorm.io/gorm"
)

func (r *Repository) HandleLeshuaNotify(ctx context.Context, params map[string]string, rawPayload string, contentType string) (*NotifyResult, error) {
	return r.HandleNotify(ctx, "leshua", params, rawPayload, contentType, "")
}
func (r *Repository) HandleNotify(ctx context.Context, provider string, params map[string]string, rawPayload string, contentType string, authorization string) (*NotifyResult, error) {
	// 退款通知会携带 merchant_refund_id 或 leshua_refund_id。
	if params["merchant_refund_id"] != "" || params["leshua_refund_id"] != "" || params["provider_refund_id"] != "" {
		return r.HandleRefundNotify(ctx, provider, params, rawPayload, contentType, authorization)
	}

	payment, err := r.findPaymentForNotify(ctx, params)
	if err != nil {
		return nil, err
	}
	runtimeConfig, err := r.runtimeConfigForPayment(ctx, payment)
	if err != nil {
		return nil, ErrPaymentUnavailable
	}
	verify, err := r.verifyNotify(ctx, payment, runtimeConfig, params, rawPayload, contentType, authorization)
	if err != nil {
		return nil, err
	}

	if amount := parseCent(params["amount"]); amount > 0 && amount != payment.AmountCent {
		if err := r.recordNotifyDiagnostic(ctx, payment.ID, params, rawPayload, contentType, verify, "amount_mismatch"); err != nil {
			r.log().Warn("支付回调诊断保存失败", paymentLogFields(ctx, appendFields(
				paymentOrderFields(payment),
				runtimeConfigFields(runtimeConfig),
				[]zap.Field{
					zap.String("diagnostic_status", "amount_mismatch"),
					zap.Error(err),
				},
			)...,
			)...)
		}
		return nil, ErrPaymentVerifyFailed
	}
	raw := withNotifyDiagnostic(params, rawPayload, contentType, verify, "verified")
	if err := r.applyChannelStatus(ctx, payment, normalizeNotifyPaymentStatus(runtimeConfig.Provider, params["status"]), params["pay_time"], raw, channelSourceNotify); err != nil {
		return nil, err
	}
	return &NotifyResult{OK: true, Message: "000000"}, nil
}
func (r *Repository) HandleRefundNotify(ctx context.Context, provider string, params map[string]string, rawPayload string, contentType string, authorization string) (*NotifyResult, error) {
	payment, err := r.findRefundPaymentForNotify(ctx, params)
	if err != nil {
		return nil, err
	}
	runtimeConfig, err := r.runtimeConfigForPayment(ctx, payment)
	if err != nil {
		return nil, ErrPaymentUnavailable
	}
	verify, err := r.verifyNotify(ctx, payment, runtimeConfig, params, rawPayload, contentType, authorization)
	if err != nil {
		return nil, err
	}

	raw := withNotifyDiagnostic(params, rawPayload, contentType, verify, "verified")
	status := normalizeNotifyRefundStatus(provider, params["status"])
	if err := r.applyRefundChannelStatus(ctx, payment, refundChannelStatusUpdate{
		Status:           status,
		ProviderRefundID: firstNonEmpty(params["provider_refund_id"], params["leshua_refund_id"]),
		RefundTime:       params["refund_time"],
		Raw:              raw,
		Source:           channelSourceNotify,
	}); err != nil {
		return nil, err
	}
	return &NotifyResult{OK: true, Message: "000000"}, nil
}
func (r *Repository) findPaymentForNotify(ctx context.Context, params map[string]string) (*model.PaymentOrder, error) {
	thirdOrderID := params["third_order_id"]
	if thirdOrderID == "" {
		return nil, ErrPaymentNotFound
	}
	var payment model.PaymentOrder
	if err := r.db.WithContext(ctx).Where("third_order_id = ?", thirdOrderID).First(&payment).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrPaymentNotFound
		}
		return nil, err
	}
	return &payment, nil
}
func (r *Repository) findRefundPaymentForNotify(ctx context.Context, params map[string]string) (*model.PaymentOrder, error) {
	merchantRefundID := params["merchant_refund_id"]
	if merchantRefundID == "" {
		return nil, ErrPaymentNotFound
	}
	var payment model.PaymentOrder
	if err := r.db.WithContext(ctx).Where("third_order_id = ?", merchantRefundID).First(&payment).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrPaymentNotFound
		}
		return nil, err
	}
	return &payment, nil
}
func (r *Repository) verifyNotify(ctx context.Context, payment *model.PaymentOrder, runtimeConfig *runtimePaymentConfig, params map[string]string, rawPayload string, contentType string, authorization string) (channelVerifyNotifyResult, error) {
	var verify channelVerifyNotifyResult
	if runtimeConfig.isMockMode() {
		return verify, nil
	}
	if runtimeConfig.Channel == nil {
		return verify, ErrPaymentUnavailable
	}
	verify, err := runtimeConfig.Channel.VerifyNotify(params, rawPayload, contentType, authorization)
	if err != nil || !verify.OK {
		r.log().Warn("支付回调验签失败", paymentLogFields(ctx, appendFields(
			paymentOrderFields(payment),
			runtimeConfigFields(runtimeConfig),
			[]zap.Field{
				zap.Bool("signature_present", verify.Got != ""),
				zap.Strings("param_keys", verify.ParamKeys),
				zap.Error(err),
			},
		)...,
		)...)
		if err := r.recordNotifyDiagnostic(ctx, payment.ID, params, rawPayload, contentType, verify, "verify_failed"); err != nil {
			r.log().Warn("支付回调诊断保存失败", paymentLogFields(ctx, appendFields(
				paymentOrderFields(payment),
				runtimeConfigFields(runtimeConfig),
				[]zap.Field{
					zap.String("diagnostic_status", "verify_failed"),
					zap.Error(err),
				},
			)...,
			)...)
		}
		return verify, ErrPaymentVerifyFailed
	}
	return verify, nil
}
func (r *Repository) recordNotifyDiagnostic(ctx context.Context, paymentID uint64, params map[string]string, rawPayload string, contentType string, verify channelVerifyNotifyResult, status string) error {
	if paymentID == 0 {
		return nil
	}
	raw := withNotifyDiagnostic(params, rawPayload, contentType, verify, status)
	return r.db.WithContext(ctx).Model(&model.PaymentOrder{}).
		Where("id = ?", paymentID).
		Update("raw_response", jsonMap(raw)).Error
}
func withNotifyDiagnostic(params map[string]string, rawPayload string, contentType string, verify channelVerifyNotifyResult, status string) map[string]string {
	raw := withRawSource(redactNotifyParams(params), channelSourceNotify)
	raw["_notify_diagnostic_status"] = status
	raw["_raw_content_type"] = contentType
	raw["_raw_payload_size"] = strconv.Itoa(len(rawPayload))
	raw["_raw_payload_sha256"] = shortDigest(rawPayload)
	raw["_signature_present"] = strconv.FormatBool(verify.Got != "")
	raw["_sign_matched_key"] = verify.MatchedKey
	raw["_sign_param_keys"] = strings.Join(verify.ParamKeys, ",")
	return raw
}

func redactNotifyParams(params map[string]string) map[string]string {
	allowed := map[string]bool{
		"service": true, "merchant_id": true, "third_order_id": true,
		"provider_order_id": true, "leshua_order_id": true, "schc_order_id": true,
		"merchant_refund_id": true, "provider_refund_id": true,
		"leshua_refund_id": true, "schc_refund_id": true,
		"status": true, "amount": true, "refund_amount": true,
		"pay_time": true, "refund_time": true,
		"code": true, "resp_code": true, "result_code": true, "error_code": true,
	}
	redacted := make(map[string]string, len(allowed))
	for key, value := range params {
		lowerKey := strings.ToLower(key)
		if allowed[lowerKey] {
			redacted[key] = value
		}
	}
	return redacted
}

func shortDigest(value string) string {
	if value == "" {
		return ""
	}
	sum := sha256.Sum256([]byte(value))
	return hex.EncodeToString(sum[:8])
}