package rest

import (
	"fmt"

	"git.ali33.ru/fcg-xvii/go-tools/json"
)

func parseCondition(m json.Map, index int) (ICondition, error) {
	errPrefix := func(errData string) error {
		return fmt.Errorf("[%v]: %s", index, errData)
	}
	cond := _condition{
		field:    m.String("field", ""),
		logic:    _conditionLogic(m.String("logic", "")),
		operator: _conditionOperator(m.String("operator", "")),
		value:    m["value"],
	}
	if !cond.IsValid() {
		if len(cond.field) == 0 {
			return nil, errPrefix("empty field name")
		} else if !cond.operator.IsValid() {
			return nil, errPrefix(fmt.Sprintf("unexpected operator [%s]", cond.operator))
		} else if !cond.operator.IsValid() {
			return nil, errPrefix(fmt.Sprintf("unexpected logic [%s]", cond.logic))
		} else {
			return nil, errPrefix("unexpected error")
		}
	}
	return &cond, nil
}

//////////////////////////////////////////////////////////////////////////////

type ICondition interface {
	Field() string
}

//////////////////////////////////////////////////////////////////////////////

type _conditionOperator string

const (
	OperatorEqual     = "="
	OperatorNotEqual  = "!="
	OperatorMore      = ">"
	OperatorLess      = "<"
	OperatorMoreEqual = ">="
	OperatorLessEqual = "<="
	OperatorLike      = "like"
)

func (s _conditionOperator) IsValid() bool {
	switch s {
	case OperatorEqual:
	case OperatorNotEqual:
	case OperatorMore:
	case OperatorLess:
	case OperatorMoreEqual:
	case OperatorLessEqual:
	case OperatorLike:
	default:
		return false
	}
	return true
}

//////////////////////////////////////////////////////////////////////////////

const (
	LogicEmpty = ""
	LogicOR    = "or"
	LogicAND   = "and"
)

type _conditionLogic string

func (s _conditionLogic) IsValid() bool {
	switch s {
	case LogicEmpty:
	case LogicOR:
	case LogicAND:
	default:
		return false
	}
	return true
}

//////////////////////////////////////////////////////////////////////////////

type _condition struct {
	field    string
	logic    _conditionLogic
	operator _conditionOperator
	value    any
}

func (s *_condition) Field() string {
	return s.field
}

func (s *_condition) Logic() _conditionLogic {
	return s.logic
}

func (s *_condition) Operator() _conditionOperator {
	return s.operator
}

func (s *_condition) IsValid() bool {
	return len(s.field) > 0 && s.logic.IsValid() && s.operator.IsValid()
}