Added session cookie and logout for admin

auth/session.go

@@ -0,0 +1,69 @@
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"net/http"
+	"sync"
+	"time"
+)
+
+var (
+	sessions = map[string]time.Time{}
+	mu       sync.Mutex
+)
+
+func GenerateSession() (string, error) {
+	bytes := make([]byte, 32)
+	_, err := rand.Read(bytes)
+	if err != nil {
+		return "", err
+	}
+	token := hex.EncodeToString(bytes)
+
+	mu.Lock()
+	sessions[token] = time.Now()
+	mu.Unlock()
+
+	return token, nil
+}
+
+func IsLoggedIn(r *http.Request) bool {
+	cookie, err := r.Cookie("session")
+	if err != nil {
+		return false
+	}
+
+	mu.Lock()
+	_, exists := sessions[cookie.Value]
+	mu.Unlock()
+
+	return exists
+}
+
+func SetSessionCookie(w http.ResponseWriter, token string) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     "session",
+		Value:    token,
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+	})
+}
+
+func ClearSession(w http.ResponseWriter, r *http.Request) {
+	cookie, err := r.Cookie("session")
+	if err == nil {
+		mu.Lock()
+		delete(sessions, cookie.Value)
+		mu.Unlock()
+	}
+
+	http.SetCookie(w, &http.Cookie{
+		Name:     "session",
+		Value:    "",
+		Path:     "/",
+		MaxAge:   -1,
+		HttpOnly: true,
+	})
+}