feat: finish project basic structure and core functions

handler/health.go

@@ -0,0 +1,28 @@
+package handler
+
+import (
+	"net/http"
+
+	"nukumizu-backend/database"
+	"nukumizu-backend/utils"
+)
+
+// HealthHandler handles GET /health.
+func HealthHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		utils.SendErrorResponse(w, http.StatusMethodNotAllowed, "method not allowed")
+		return
+	}
+
+	dbStatus := "ok"
+	if database.UserDB == nil {
+		dbStatus = "not initialized"
+	} else if err := database.UserDB.Ping(); err != nil {
+		dbStatus = "error: " + err.Error()
+	}
+
+	utils.SendSuccessResponse(w, "", map[string]interface{}{
+		"status":   "ok",
+		"database": dbStatus,
+	})
+}