package coll

import (
	"errors"
	"reflect"
)

type Set[E comparable] map[E]struct{}

func OfSet[E comparable](set *map[E]struct{}) *Set[E] {
	return (*Set[E])(set)
}

func OfSet4Arr[E comparable](arr []E) *Set[E] {
	set := make(map[E]struct{}, len(arr))
	for _, ele := range arr {
		set[ele] = struct{}{}
	}
	return (*Set[E])(&set)
}

func (my *Set[E]) ToList() *List[E] {
	list := make([]E, 0, my.Size())
	for key := range *my {
		list = append(list, key)
	}
	return OfList(&list)
}

func (my *Set[E]) Add(ele E) {
	if !my.isValid(ele) {
		panic(errors.New("无效元素"))
	}
	(*my)[ele] = struct{}{}
}

func (my *Set[E]) Remove(ele E) bool {
	if !my.Contains(ele) {
		return false
	}
	delete(*my, ele)
	return true
}

func (my *Set[E]) Size() int {
	return len(*my)
}

func (my *Set[E]) Contains(ele E) bool {
	if !my.isValid(ele) {
		return false
	}
	_, ok := (*my)[ele]
	return ok
}

func (my *Set[E]) IsEmpty() bool {
	return *my == nil || my.Size() == 0
}

func (my *Set[E]) isValid(ele E) bool {
	rv := reflect.Indirect(reflect.ValueOf(ele))
	if rv.IsZero() || rv.IsNil() {
		return false
	}
	return rv.IsValid()
}