package mysqldao

import (
	"context"

	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/global"
	"git.lzcwy.cn/zhengchiliu/zt-closet-manage-backend/internal/mysqlmodel"
	"gorm.io/gorm"
)

// RefundDao 退款单数据访问
type RefundDao struct {
	db *gorm.DB
}

// NewRefundDao 创建退款 DAO
func NewRefundDao() *RefundDao {
	return &RefundDao{db: global.MysqlEngine}
}

// RefundListParams 退款单分页列表筛选参数。
type RefundListParams struct {
	Status     int8   // 退款状态（WithStatus 为 true 时生效）
	WithStatus bool   // 是否按状态筛选（退款状态 0=待处理 是合法值，需显式区分「不过滤」）
	OrderNo    string // 订单号（精确）
	Page       int
	Size       int
}

// RefundList 分页查询退款单
func (d *RefundDao) RefundList(ctx context.Context, p RefundListParams) ([]mysqlmodel.RefundFlowLog, int64, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.RefundList")
	defer span.End()

	var list []mysqlmodel.RefundFlowLog
	var total int64
	q := d.db.WithContext(ctx).Model(&mysqlmodel.RefundFlowLog{})
	if p.WithStatus {
		q = q.Where("status = ?", p.Status)
	}
	if p.OrderNo != "" {
		q = q.Where("order_no = ?", p.OrderNo)
	}
	if err := q.Count(&total).Error; err != nil {
		span.RecordError(err)
		return nil, 0, err
	}
	if err := q.Offset((p.Page - 1) * p.Size).Limit(p.Size).Order("id DESC").Find(&list).Error; err != nil {
		span.RecordError(err)
		return nil, 0, err
	}
	return list, total, nil
}

// RefundGetByRefundNo 按退款单号查询
func (d *RefundDao) RefundGetByRefundNo(ctx context.Context, refundNo string) (*mysqlmodel.RefundFlowLog, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.RefundGetByRefundNo")
	defer span.End()

	var refund mysqlmodel.RefundFlowLog
	if err := d.db.WithContext(ctx).Where("refund_no = ?", refundNo).First(&refund).Error; err != nil {
		span.RecordError(err)
		return nil, err
	}
	return &refund, nil
}

// RefundTransition 条件更新退款状态（仅 from 状态可流转到 to，行锁防并发重复审核）。
func (d *RefundDao) RefundTransition(ctx context.Context, refundNo string, from, to int8, failReason string) (bool, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.RefundTransition")
	defer span.End()

	updates := map[string]any{"status": to}
	if failReason != "" {
		updates["fail_reason"] = failReason
	}
	res := d.db.WithContext(ctx).Model(&mysqlmodel.RefundFlowLog{}).
		Where("refund_no = ? AND status = ?", refundNo, from).
		Updates(updates)
	if res.Error != nil {
		span.RecordError(res.Error)
		return false, res.Error
	}
	return res.RowsAffected > 0, nil
}