package wrapper

import (
	"gitee.com/h79/goutils/dao/option"
	"strings"
)

const (
	kDesc = "DESC"
	kAsc  = "ASC"
)

var _ IBuilder = (*OrderBy)(nil)

// OrderBy 排序（降序（大=>小）desc, 升序（小=>大）asc
// example: "orderBy：[{"col:"create_at","desc":true}, {"col":"id","desc":false}]
//
//	"orderBy：[{"col:"create_at,id","desc":true}]
type OrderBy []Column

func (ob *OrderBy) Is() bool {
	return len(*ob) > 0
}

func (ob *OrderBy) Build(opts ...option.Option) string {
	var ii = 0
	var m = 6
	var full = false
	var convert option.ColumnConvertFunc
	option.Filter(func(opt option.Option) bool {
		if opt.Type() == option.TypeMaxColumn {
			m = opt.Value().(int)
			ii++
		} else if opt.Type() == option.TypeFullSql {
			full = opt.Value().(bool)
			ii++
		} else if opt.Type() == option.TypeSqlColumnConvert {
			convert = opt.Value().(option.ColumnConvertFunc)
			ii++
		}
		return ii == 3
	}, opts...)
	return ob.buildOpt(full, convert, m)
}

func (ob *OrderBy) Check(filters []FField, opts ...option.Option) {
	length := len(*ob)
	var m = option.MaxColumnExist(opts...)
	if length > m { //防止多
		length = m
	}
	cols := (*ob)[:length]
	for i := range cols {
		cols[i].Check(filters)
	}
}

func (ob *OrderBy) buildOpt(full bool, convert option.ColumnConvertFunc, max int) string {
	count := 0
	builder := strings.Builder{}
	for i := range *ob {
		if count >= max {
			//后面不要接入
			break
		}
		if c := ob.build(&(*ob)[i], convert); len(c) > 0 {
			if count == 0 {
				if full {
					builder.WriteString(" ORDER BY ")
				}
			} else if count > 0 {
				builder.WriteByte(',')
			}
			builder.WriteString(c)
			count++
		}
	}
	return builder.String()
}

func (ob *OrderBy) build(col *Column, convert option.ColumnConvertFunc) string {
	var cc = false
	var builder = strings.Builder{}
	if convert != nil {
		cc = SqlColumn(&builder, convert(col.Column))
	} else {
		cc = SqlColumn(&builder, col.Column)
	}
	if cc && col.Desc {
		builder.WriteByte(' ')
		builder.WriteString(kDesc)
	}
	return builder.String()
}