package utils

import (
	"crypto/tls"
	"sync"
	"time"
)

type CertCache struct {
	syncLock *sync.RWMutex
	certs    map[string]*certCacheItem
}

func NewCertCache() *CertCache {
	return &CertCache{&sync.RWMutex{}, make(map[string]*certCacheItem)}
}

func (cc *CertCache) Put(domain string, cert *tls.Certificate) {
	cc.syncLock.Lock()
	a, ok := cc.certs[domain]
	if ok {
		a.tick.Stop()
		close(a.end)
		delete(cc.certs, domain)
	}

	// Set up a ticker and timeout value
	i := &certCacheItem{cert, time.NewTicker(time.Minute * 10), make(chan struct{})}
	go cc.internalItemTick(domain, i)
	cc.certs[domain] = i
	cc.syncLock.Unlock()
}

func (cc *CertCache) Get(domain string) (*tls.Certificate, bool) {
	cc.syncLock.RLock()
	c, ok := cc.certs[domain]
	cc.syncLock.RUnlock()
	if ok {
		return c.cert, ok
	}
	return nil, false
}

func (cc *CertCache) Del(domain string) {
	cc.syncLock.Lock()
	a, ok := cc.certs[domain]
	if ok {
		a.tick.Stop()
		close(a.end)
	}
	delete(cc.certs, domain)
	cc.syncLock.Unlock()
}

func (cc *CertCache) internalItemTick(domain string, item *certCacheItem) {
	select {
	case <-item.tick.C:
		cc.Del(domain)
	case <-item.end:
	}
}

type certCacheItem struct {
	cert *tls.Certificate
	tick *time.Ticker
	end  chan struct{}
}