Refactor router status transitions and remove READY state

src/main/java/com/litoralregas/openvpn/router/Router.java

@@ -15,7 +15,8 @@ public class Router {
     private String serialNumber;
     private String lanIp;
     private String lanSubnet;
-    private String status;
+    @Enumerated(EnumType.STRING)
+    private RouterStatus status;
 
     private LocalDateTime createdAt;
     private LocalDateTime updatedAt;
@@ -63,11 +64,11 @@ public class Router {
         this.lanSubnet = lanSubnet;
     }
 
-    public String getStatus() {
+    public RouterStatus getStatus() {
         return status;
     }
 
-    public void setStatus(String status) {
+    public void setStatus(RouterStatus status) {
         this.status = status;
     }
 

src/main/java/com/litoralregas/openvpn/router/RouterService.java

@@ -32,7 +32,7 @@ public class RouterService {
         router.setSerialNumber(request.getSerialNumber());
         router.setLanIp(request.getLanIp());
         router.setLanSubnet(request.getLanSubnet());
-        router.setStatus("PENDING");
+        router.setStatus(RouterStatus.PENDING);
         router.setCreatedAt(now);
         router.setUpdatedAt(now);
 
@@ -47,7 +47,16 @@ public class RouterService {
     public Router updateStatus(UUID id, UpdateRouterStatusRequest request) {
         Router router = findById(id);
 
-        router.setStatus(request.getStatus());
+        RouterStatus current = router.getStatus();
+        RouterStatus next = request.getStatus();
+
+        if (!isValidTransition(current, next)) {
+            throw new IllegalArgumentException(
+                    "Invalid status transition: " + current + " → " + next
+            );
+        }
+
+        router.setStatus(next);
         router.setUpdatedAt(LocalDateTime.now());
 
         return repository.save(router);
@@ -57,4 +66,13 @@ public class RouterService {
         Router router = findById(id);
         repository.delete(router);
     }
+
+    private boolean isValidTransition(RouterStatus current, RouterStatus next) {
+        return switch (current) {
+            case PENDING, FAILED -> next == RouterStatus.PROVISIONING;
+            case PROVISIONING -> next == RouterStatus.PROVISIONED || next == RouterStatus.FAILED;
+            case PROVISIONED -> next == RouterStatus.REMOVED;
+            case REMOVED -> false;
+        };
+    }
 }

src/main/java/com/litoralregas/openvpn/router/RouterStatus.java

@@ -0,0 +1,9 @@
+package com.litoralregas.openvpn.router;
+
+public enum RouterStatus {
+    PENDING,
+    PROVISIONING,
+    PROVISIONED,
+    FAILED,
+    REMOVED
+}

src/main/java/com/litoralregas/openvpn/router/UpdateRouterStatusRequest.java

@@ -5,13 +5,13 @@ import jakarta.validation.constraints.NotBlank;
 public class UpdateRouterStatusRequest {
 
     @NotBlank
-    private String status;
+    private RouterStatus status;
 
-    public String getStatus() {
+    public RouterStatus getStatus() {
         return status;
     }
 
-    public void setStatus(String status) {
+    public void setStatus(RouterStatus status) {
         this.status = status;
     }
 }