package security

import (
	"sync"
	"time"
)

type NonceStore struct {
	mu  sync.Mutex
	m   map[string]int64
	ttl time.Duration
}

func NewNonceStore(ttl time.Duration) *NonceStore {
	return &NonceStore{m: map[string]int64{}, ttl: ttl}
}

func (s *NonceStore) Use(nonce string, now time.Time) bool {
	s.mu.Lock()
	defer s.mu.Unlock()
	if exp, ok := s.m[nonce]; ok && exp >= now.Unix() {
		return false
	}
	s.m[nonce] = now.Add(s.ttl).Unix()
	for k, v := range s.m {
		if v < now.Unix() {
			delete(s.m, k)
		}
	}
	return true
}