where.go

package lama

import (
	"database/sql"
	"strings"
)

type Where struct {
	Expr  string
	Op    string
	Value interface{}
	Or    []Where
	Args  []sql.NamedArg
	Raw   string
	Fake bool
}

func (w *Where) Build(di Dialect) (string, []sql.NamedArg) {
	if w.Args == nil {
		w.Args = make([]sql.NamedArg,0)
	}
	bnN := "arg"
	if len(w.Expr) > 0 {
		n := strings.TrimLeft(w.Expr, "(")
		n = strings.TrimLeft(n, "/")
		n = strings.TrimLeft(n, ":")
		n = strings.TrimLeft(n, ".")
		n = strings.TrimLeft(n, ",")
		n = strings.TrimLeft(n, "'")
		n = strings.TrimLeft(n, `"`)
		ln := len(n)
		if ln >= 3 {
			chr := []rune(n)
			bnN = string(chr[0:3])
		} else {
			chr := []rune(n)
			bnN = string(chr[0:ln])
		}
	}
	bnN = strings.TrimSpace(bnN)
	if bnN == "" {
		bnN = "arg"
	}
	//name := bnN + strconv.Itoa(rand.Int())
	name:=getArgName(bnN)
	or := ""
	if w.Or != nil {
		for idx := range w.Or {
			o:=w.Or[idx]
			stm, args := o.Build(di)
			if idx == 0 {
				or = stm
			} else {
				or = or + " OR " + stm
			}
			for i := range args {
				//w.Args[a] = b
				w.Args=append(w.Args,args[i])
			}
		}
	}
	wh := ""
	if len(w.Expr) > 0 {
		wh = "(" + w.Expr + w.Op + di.BindVarStr(name) + ")"
		w.Args = append(w.Args, sql.NamedArg{Name: name, Value: w.Value})
		//w.Args[name] = w.Value
	}
	if len(w.Raw) > 0 {
		wh = "(" + w.Raw + ")"
	}
	if len(or) > 0 {
		if len(wh) > 0 {
			wh = "(" + wh + " and (" + or + "))"
		} else {
			wh = "(" + or + ")"
		}
	}
	return wh, w.Args
}