package util

import "encoding/json"

type present struct{}

// Waiting for Go 18...
// type Set[T comparable] map[T]present
type StringSet map[string]present

func NewStringSet(elements ...string) StringSet {
	set := StringSet{}

	for _, elem := range elements {
		set.Add(elem)
	}

	return set
}

func (set StringSet) Has(value string) bool {
	_, present := set[value]
	return present
}

func (set StringSet) HasAny(values ...string) bool {
	for _, value := range values {
		if _, present := set[value]; present {
			return true
		}
	}
	return false
}

func (set StringSet) Contains(other StringSet) bool {
	for v := range other {
		if !set.Has(v) {
			return false
		}
	}
	return true
}

func (set StringSet) Add(value string) {
	set[value] = present{}
}

func (set StringSet) Remove(value string) {
	delete(set, value)
}

func (set StringSet) Elements() []string {
	elements := []string{}

	for elem := range set {
		elements = append(elements, elem)
	}

	return elements
}

func (set StringSet) MarshalJSON() ([]byte, error) {
	return json.Marshal(set.Elements())
}

func (set StringSet) UnmarshalJSON(data []byte) error {
	elements := []string{}
	if err := json.Unmarshal(data, &elements); err != nil {
		return err
	}

	for _, v := range elements {
		set.Add(v)
	}

	return nil
}