From 9d0e49c4615cc18dc1277ab57043ae6ab632cd4a Mon Sep 17 00:00:00 2001
From: qowevisa <qowevisa@gmail.com>
Date: Fri, 7 Jun 2024 21:57:23 +0300
Subject: [PATCH] Add a lot to server

---
 cmd/server/links.go | 54 +++++++++++++++++++++++++++++++++++++++++++++
 cmd/server/main.go  | 46 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)
 create mode 100644 cmd/server/links.go

diff --git a/cmd/server/links.go b/cmd/server/links.go
new file mode 100644
index 0000000..143ef1e
--- /dev/null
+++ b/cmd/server/links.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"sync"
+
+	com "git.qowevisa.me/Qowevisa/gotell/communication"
+)
+
+type UserLink struct {
+	LeftNum uint16
+	UserID  uint16
+}
+
+type LinkCenter struct {
+	Links map[string]*UserLink
+	Mu    sync.Mutex
+}
+
+var (
+	linkCenter LinkCenter
+)
+
+func (l *LinkCenter) Init() {
+	l.Links = make(map[string]*UserLink)
+}
+
+func (l *LinkCenter) AddLink(id uint16, link com.Link) error {
+	_, found := l.Links[string(link.Data)]
+	if found {
+		return ERROR_ALREADY_HAVE
+	}
+	l.Mu.Lock()
+	l.Links[string(link.Data)] = &UserLink{
+		LeftNum: link.UseCount,
+		UserID:  id,
+	}
+	l.Mu.Unlock()
+	return nil
+}
+
+func (l *LinkCenter) DeleteLink(data []byte) error {
+	l.Mu.Lock()
+	delete(l.Links, string(data))
+	l.Mu.Unlock()
+	return nil
+}
+
+func (l *LinkCenter) GetLink(data []byte) (*UserLink, error) {
+	val, found := l.Links[string(data)]
+	if !found {
+		return nil, ERROR_DONT_HAVE
+	}
+	return val, nil
+}
diff --git a/cmd/server/main.go b/cmd/server/main.go
index 307d176..5d742b6 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -15,6 +15,7 @@ import (
 
 func main() {
 	userCenter.Init()
+	linkCenter.Init()
 	host, err := env.GetHost()
 	if err != nil {
 		log.Fatal(err)
@@ -110,6 +111,51 @@ func handleClient(conn net.Conn) {
 				registeredID = id
 			}
 		case com.ID_CLIENT_SEND_SERVER_LINK:
+			l, err := com.DecodeLink(msg.Data)
+			if err != nil {
+				log.Printf("ERROR: DecodeLink: %v\n", err)
+				continue
+			}
+			err = linkCenter.AddLink(msg.FromID, *l)
+			if err != nil {
+				log.Printf("ERROR: AddLink: %v\n", err)
+				answ, err := com.ServerDeclineClientLink()
+				if err != nil {
+					log.Printf("ERROR: BYTES: %v\n", err)
+					continue
+				}
+				conn.Write(answ)
+				continue
+			}
+			answ, err := com.ServerApproveClientLink()
+			if err != nil {
+				log.Printf("ERROR: BYTES: %v\n", err)
+				continue
+			}
+			conn.Write(answ)
+		case com.ID_CLIENT_ASK_SERVER_LINK:
+			link, err := linkCenter.GetLink(msg.Data)
+			if err != nil {
+				log.Printf("Error: %v\n", err)
+				continue
+			}
+			if link.LeftNum == 0 {
+				linkCenter.DeleteLink(msg.Data)
+				continue
+			}
+			// TODO: there can be an error on multi-thread app
+			link.LeftNum -= 1
+			name, err := userCenter.GetName(link.UserID)
+			if err != nil {
+				log.Printf("ERROR: userCenter: Getname: %v\n", err)
+				continue
+			}
+			answ, err := com.ServerSendClientIDFromLink(link.UserID, []byte(name))
+			if err != nil {
+				log.Printf("ERROR: BYTES: %v\n", err)
+				continue
+			}
+			conn.Write(answ)
 		default:
 		}
 		// Handle