add cron, nat api & refactor alert rule (#459)

* add cron api & refactor alert rule

* add nat api

* fix swagger

* remove unnecessary steps

service/singleton/nat.go

@@ -1,31 +1,75 @@
 package singleton
 
 import (
+	"slices"
 	"sync"
 
 	"github.com/naiba/nezha/model"
 )
 
-var natCache = make(map[string]*model.NAT)
-var natCacheRwLock = new(sync.RWMutex)
+var (
+	NATCache       = make(map[string]*model.NAT)
+	NATCacheRwLock sync.RWMutex
+
+	NATIDToDomain = make(map[uint64]string)
+	NATList       []*model.NAT
+)
 
 func initNAT() {
-	OnNATUpdate()
-}
-
-func OnNATUpdate() {
-	natCacheRwLock.Lock()
-	defer natCacheRwLock.Unlock()
-	var nats []*model.NAT
-	DB.Find(&nats)
-	natCache = make(map[string]*model.NAT)
-	for i := 0; i < len(nats); i++ {
-		natCache[nats[i].Domain] = nats[i]
+	DB.Find(&NATList)
+	NATCacheRwLock.Lock()
+	defer NATCacheRwLock.Unlock()
+	NATCache = make(map[string]*model.NAT)
+	for i := 0; i < len(NATList); i++ {
+		NATCache[NATList[i].Domain] = NATList[i]
+		NATIDToDomain[NATList[i].ID] = NATList[i].Domain
 	}
 }
 
-func GetNATConfigByDomain(domain string) *model.NAT {
-	natCacheRwLock.RLock()
-	defer natCacheRwLock.RUnlock()
-	return natCache[domain]
+func OnNATUpdate(n *model.NAT) {
+	NATCacheRwLock.Lock()
+	defer NATCacheRwLock.Unlock()
+
+	if oldDomain, ok := NATIDToDomain[n.ID]; ok && oldDomain != n.Domain {
+		delete(NATCache, oldDomain)
+	}
+
+	NATCache[n.Domain] = n
+	NATIDToDomain[n.ID] = n.Domain
+}
+
+func OnNATDelete(id []uint64) {
+	NATCacheRwLock.Lock()
+	defer NATCacheRwLock.Unlock()
+
+	for _, i := range id {
+		if domain, ok := NATIDToDomain[i]; ok {
+			delete(NATCache, domain)
+			delete(NATIDToDomain, i)
+		}
+	}
+}
+
+func UpdateNATList() {
+	NATCacheRwLock.RLock()
+	defer NATCacheRwLock.RUnlock()
+
+	NATList = make([]*model.NAT, 0, len(NATCache))
+	for _, n := range NATCache {
+		NATList = append(NATList, n)
+	}
+	slices.SortFunc(NATList, func(a, b *model.NAT) int {
+		if a.ID < b.ID {
+			return -1
+		} else if a.ID == b.ID {
+			return 0
+		}
+		return 1
+	})
+}
+
+func GetNATConfigByDomain(domain string) *model.NAT {
+	NATCacheRwLock.RLock()
+	defer NATCacheRwLock.RUnlock()
+	return NATCache[domain]
 }