package collect

import (
	"sync"
	"time"

	"github.com/v2ray/v2ray-core/common/serial"
)

type Validity interface {
	IsValid() bool
}

type entry struct {
	key   string
	value Validity
}

type ValidityMap struct {
	sync.RWMutex
	cache              map[string]Validity
	cleanupIntervalSec int
}

func NewValidityMap(cleanupIntervalSec int) *ValidityMap {
	instance := &ValidityMap{
		cache:              make(map[string]Validity),
		cleanupIntervalSec: cleanupIntervalSec,
	}
	go instance.cleanup()
	return instance
}

func (this *ValidityMap) cleanup() {
	for range time.Tick(time.Duration(this.cleanupIntervalSec) * time.Second) {
		entry2Remove := make([]entry, 0, 128)
		this.RLock()
		for key, value := range this.cache {
			if !value.IsValid() {
				entry2Remove = append(entry2Remove, entry{
					key:   key,
					value: value,
				})
			}
		}
		this.RUnlock()

		for _, entry := range entry2Remove {
			if !entry.value.IsValid() {
				this.Lock()
				delete(this.cache, entry.key)
				this.Unlock()
			}
		}
	}
}

func (this *ValidityMap) Set(key serial.String, value Validity) {
	this.Lock()
	this.cache[key.String()] = value
	this.Unlock()
}

func (this *ValidityMap) Get(key serial.String) Validity {
	this.RLock()
	defer this.RUnlock()
	if value, found := this.cache[key.String()]; found {
		return value
	}
	return nil
}