package payment

import (
	"context"
	"fmt"

	"hfb_sys/backend/internal/model"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

const qualityOwnerPayBizType = "quality_owner_pay"

// StartQualityOwner 创建优质号主保证金在线支付单，支付成功后自动开通资格并冻结保证金。
func (r *Repository) StartQualityOwner(ctx context.Context, userID uint64, req StartPaymentRequest, clientIP string) (*PaymentDTO, error) {
	if r.qualityOwnerRepo == nil {
		return nil, ErrDependencyUnavailable
	}
	req.PayWay = normalizePayWay(req.PayWay)
	payment, err := r.prepareQualityOwnerPayment(ctx, userID, req)
	if err != nil {
		return nil, err
	}
	return r.startPreparedPayment(ctx, payment, "优质号主保证金", payment.OrderNo, clientIP)
}

func (r *Repository) prepareQualityOwnerPayment(ctx context.Context, userID uint64, req StartPaymentRequest) (*model.PaymentOrder, error) {
	amountCent, active, err := r.qualityOwnerRepo.PaymentAmount(ctx, userID)
	if err != nil {
		return nil, err
	}
	if active || amountCent <= 0 {
		return nil, ErrPaymentCannotStart
	}
	runtimeConfig, err := r.defaultRuntimeConfig(ctx, req.PayWay)
	if err != nil {
		return nil, err
	}

	var paymentID uint64
	err = r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		var user model.User
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Select("id").
			First(&user, userID).Error; err != nil {
			return err
		}
		var existing model.PaymentOrder
		err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
			Where("user_id = ? AND biz_type = ? AND biz_id = ?", userID, qualityOwnerPayBizType, userID).
			Order("id DESC").
			First(&existing).Error
		if err == nil {
			if canReuseQualityOwnerPayment(existing, *runtimeConfig) {
				existing.PayWay = firstNonEmpty(req.PayWay, existing.PayWay, runtimeConfig.PayWay, "ZFBZF")
				existing.JSPayFlag = firstNonEmpty(req.JSPayFlag, existing.JSPayFlag, runtimeConfig.JSPayFlag, "2")
				existing.AmountCent = amountCent
				existing.PaymentConfigID = firstNonZero(existing.PaymentConfigID, runtimeConfig.ID)
				existing.Provider = firstNonEmpty(existing.Provider, runtimeConfig.Provider)
				existing.MerchantID = firstNonEmpty(existing.MerchantID, runtimeConfig.MerchantID)
				if existing.Provider == "mock" && existing.ProviderOrderID == "" {
					existing.ProviderOrderID = "MOCK" + existing.ThirdOrderID
				}
				if err := tx.Save(&existing).Error; err != nil {
					return err
				}
				paymentID = existing.ID
				return nil
			}
		} else if err != gorm.ErrRecordNotFound {
			return err
		}
		payment, err := newQualityOwnerPayment(userID, amountCent, req, *runtimeConfig)
		if err != nil {
			return err
		}
		if err := tx.Create(&payment).Error; err != nil {
			return err
		}
		paymentID = payment.ID
		return nil
	})
	if err != nil {
		return nil, err
	}
	return r.findPaymentByID(ctx, paymentID)
}

// canReuseQualityOwnerPayment 仅复用尚未完成的有效支付单。
// 已支付单属于上一轮开通周期，取消后必须重新创建支付单，避免“旧单已支付”被误当成新一轮开通。
func canReuseQualityOwnerPayment(payment model.PaymentOrder, runtimeConfig runtimePaymentConfig) bool {
	if payment.Status == "paid" {
		return false
	}
	return canReuseOrderPayment(payment, runtimeConfig)
}

func newQualityOwnerPayment(userID uint64, amountCent int64, req StartPaymentRequest, runtimeConfig runtimePaymentConfig) (model.PaymentOrder, error) {
	paymentNo, err := newPaymentNo()
	if err != nil {
		return model.PaymentOrder{}, err
	}
	orderNo := fmt.Sprintf("QO%d", userID)
	payment := model.PaymentOrder{
		PaymentNo:       paymentNo,
		OrderID:         0,
		OrderNo:         orderNo,
		BizID:           userID,
		UserID:          userID,
		PaymentConfigID: runtimeConfig.ID,
		Provider:        runtimeConfig.Provider,
		MerchantID:      runtimeConfig.MerchantID,
		ThirdOrderID:    paymentNo,
		PayWay:          firstNonEmpty(req.PayWay, runtimeConfig.PayWay, "ZFBZF"),
		JSPayFlag:       firstNonEmpty(req.JSPayFlag, runtimeConfig.JSPayFlag, "2"),
		AmountCent:      amountCent,
		BizType:         qualityOwnerPayBizType,
		Status:          "created",
	}
	if runtimeConfig.isMockMode() {
		payment.ProviderOrderID = "MOCK" + paymentNo
		payment.TDCode = "mock://payment/pay/" + paymentNo
	}
	return payment, nil
}

func (r *Repository) QueryQualityOwner(ctx context.Context, userID uint64) (*PaymentDTO, error) {
	var payment model.PaymentOrder
	if err := r.db.WithContext(ctx).
		Where("user_id = ? AND biz_type = ? AND biz_id = ?", userID, qualityOwnerPayBizType, userID).
		Order("id DESC").
		First(&payment).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrPaymentNotFound
		}
		return nil, err
	}
	if isOrderPaymentTerminalStatus(payment.Status) {
		dto := toDTO(payment)
		return &dto, nil
	}
	runtimeConfig, err := r.runtimeConfigForPayment(ctx, &payment)
	if err != nil {
		return nil, ErrPaymentUnavailable
	}
	if runtimeConfig.isMockMode() {
		dto := toDTO(payment)
		return &dto, nil
	}
	if runtimeConfig.Channel == nil {
		return nil, ErrPaymentUnavailable
	}
	resp, err := runtimeConfig.Channel.QueryPayment(ctx, payment.ThirdOrderID, payment.ProviderOrderID)
	if err != nil {
		return nil, err
	}
	if err := r.applyChannelStatus(ctx, &payment, resp.Status, resp.PayTime, resp.Raw, channelSourceQuery); err != nil {
		return nil, err
	}
	latest, err := r.findPaymentByID(ctx, payment.ID)
	if err != nil {
		return nil, err
	}
	dto := toDTO(*latest)
	return &dto, nil
}