package aoc

import "slices"

type Set map[string]bool

func NewSet(l int) Set {
	return make(map[string]bool, l)
}

func NewSetFromValues(v ...string) Set {
	s := NewSet(len(v))
	for _, val := range v {
		s[val] = true
	}
	return s
}

func (s Set) Add(nm string) {
	s[nm] = true
}

func (s Set) Remove(nm string) {
	delete(s, nm)
}

func (s Set) Contains(nm string) bool {
	_, ok := s[nm]
	return ok
}

func (s Set) Empty() bool {
	return len(s) == 0
}

func (s Set) Size() int {
	return len(s)
}

func (s Set) Intersection(o Set) Set {
	smallest, toCheck := s, o
	if o.Size() < s.Size() {
		smallest, toCheck = o, s
	}
	ix := NewSet(smallest.Size())
	for nm := range smallest {
		if toCheck.Contains(nm) {
			ix.Add(nm)
		}
	}
	return ix
}

func (s Set) Union(o Set) Set {
	un := NewSet(s.Size() + o.Size())
	for nm := range s {
		un.Add(nm)
	}
	for nm := range o {
		un.Add(nm)
	}
	return un
}

func (s Set) ToSortedSlice() []string {
	sl := make([]string, 0, s.Size())
	for nm := range s {
		sl = append(sl, nm)
	}
	slices.Sort(sl)
	return sl
}