优化目录结构

backend/src/main/java/com/openisle/controller/AiController.java

@@ -0,0 +1,40 @@
+package com.openisle.controller;
+
+import com.openisle.service.OpenAiService;
+import com.openisle.service.AiUsageService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/ai")
+@RequiredArgsConstructor
+public class AiController {
+
+    private final OpenAiService openAiService;
+    private final AiUsageService aiUsageService;
+
+    @PostMapping("/format")
+    public ResponseEntity<Map<String, String>> format(@RequestBody Map<String, String> req,
+                                                     Authentication auth) {
+        String text = req.get("text");
+        if (text == null) {
+            return ResponseEntity.badRequest().build();
+        }
+        int limit = aiUsageService.getFormatLimit();
+        int used = aiUsageService.getCount(auth.getName());
+        if (limit > 0 && used >= limit) {
+            return ResponseEntity.status(429).build();
+        }
+        aiUsageService.incrementAndGetCount(auth.getName());
+        return openAiService.formatMarkdown(text)
+                .map(t -> ResponseEntity.ok(Map.of("content", t)))
+                .orElse(ResponseEntity.status(500).build());
+    }
+}