package niri

import (
	"encoding/json"
	"errors"
)

type LayoutSwitchTarget struct {
	prev  Option[bool]
	next  Option[bool]
	index Option[int]
}

func LayoutSwitchTargetPrev() LayoutSwitchTarget {
	return LayoutSwitchTarget{prev: OptionOf(true)}
}

func LayoutSwitchTargetNext() LayoutSwitchTarget {
	return LayoutSwitchTarget{next: OptionOf(true)}
}

func LayoutSwitchTargetIndex(index int) LayoutSwitchTarget {
	return LayoutSwitchTarget{index: OptionOf(index)}
}

func (m LayoutSwitchTarget) MarshalJSON() ([]byte, error) {
	if m.prev != nil {
		return json.Marshal("Prev")
	} else if m.next != nil {
		return json.Marshal("Next")
	} else if m.index != nil {
		return json.Marshal(map[string]int{"Index": *m.index})
	}

	return nil, errors.New("LayoutSwitchTarget.MarshalJson()")
}