package orm

import (
	"git.fsdpf.net/go/contracts"
	"git.fsdpf.net/go/db"
)

type OrderByDirection string
type OrderByType string

const (
	OrderByDirection_ASC  OrderByDirection = db.ORDER_ASC
	OrderByDirection_DESC OrderByDirection = db.ORDER_DESC
)

type OrderBy struct {
	sql       string           // SQL 或 字段
	direction OrderByDirection // 排序方向
}

func NewOrderBy(sql string, params ...OrderByDirection) contracts.OrderBy {
	direction := OrderByDirection_ASC
	if len(params) > 0 {
		direction = params[0]
	}

	return OrderBy{sql, direction}
}

func (this OrderBy) ToSql() db.Expression {
	return db.Raw(this.sql + " " + string(this.direction))
}

func (this OrderBy) Inject(dbBuilder *db.Builder, m contracts.Model) {
	dbBuilder.OrderBy(this.ToSql())
}