sample by chatgpt

backend/api.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+    "context"
+    "encoding/json"
+    "log"
+    "net/http"
+    "github.com/redis/go-redis/v9"
+)
+
+var ctx = context.Background()
+
+// Message struct represents the data structure
+type Message struct {
+    ID      string `json:"id"`
+    Content string `json:"content"`
+}
+
+// Initialize Redis client
+var rdb *redis.Client
+
+func initRedis() {
+    rdb = redis.NewClient(&redis.Options{
+        Addr:     "localhost:6379", // Redis server address
+        Password: "",               // No password set
+        DB:       0,                // Use default DB
+    })
+}
+
+// Handler for getting all messages
+func getMessages(w http.ResponseWriter, r *http.Request) {
+    w.Header().Set("Content-Type", "application/json")
+
+    // Use a SCAN operation instead of KEYS to avoid performance issues with large datasets
+    var messages []Message
+    iter := rdb.Scan(ctx, 0, "*", 0).Iterator()
+    for iter.Next(ctx) {
+        id := iter.Val()
+        content, err := rdb.Get(ctx, id).Result()
+        if err != nil {
+            http.Error(w, "Failed to get message content", http.StatusInternalServerError)
+            return
+        }
+        messages = append(messages, Message{ID: id, Content: content})
+    }
+    if err := iter.Err(); err != nil {
+        http.Error(w, "Failed to scan keys", http.StatusInternalServerError)
+        return
+    }
+
+    json.NewEncoder(w).Encode(messages)
+}
+
+// Handler for getting a single message by ID
+func getMessage(w http.ResponseWriter, r *http.Request) {
+    id := r.URL.Query().Get("id")
+    if id == "" {
+        http.Error(w, "ID is required", http.StatusBadRequest)
+        return
+    }
+
+    content, err := rdb.Get(ctx, id).Result()
+    if err == redis.Nil {
+        http.Error(w, "Message not found", http.StatusNotFound)
+        return
+    } else if err != nil {
+        http.Error(w, "Failed to get message", http.StatusInternalServerError)
+        return
+    }
+
+    w.Header().Set("Content-Type", "application/json")
+    json.NewEncoder(w).Encode(Message{ID: id, Content: content})
+}
+
+// Handler for adding a new message
+func addMessage(w http.ResponseWriter, r *http.Request) {
+    var msg Message
+    err := json.NewDecoder(r.Body).Decode(&msg)
+    if err != nil {
+        http.Error(w, "Invalid input", http.StatusBadRequest)
+        return
+    }
+
+    err = rdb.Set(ctx, msg.ID, msg.Content, 0).Err()
+    if err != nil {
+        http.Error(w, "Failed to save message", http.StatusInternalServerError)
+        return
+    }
+
+    w.WriteHeader(http.StatusCreated)
+}
+
+func main() {
+    // Initialize Redis connection
+    initRedis()
+
+    http.HandleFunc("/messages", getMessages)
+    http.HandleFunc("/message", getMessage)
+    http.HandleFunc("/add-message", addMessage)
+    
+    log.Println("Server started at :8080")
+    log.Fatal(http.ListenAndServe(":8080", nil))
+}
+