feat: add OpenAI markdown format endpoint

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

@@ -0,0 +1,30 @@
+package com.openisle.controller;
+
+import com.openisle.service.OpenAiService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+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;
+
+    @PostMapping("/format")
+    public ResponseEntity<Map<String, String>> format(@RequestBody Map<String, String> req) {
+        String text = req.get("text");
+        if (text == null) {
+            return ResponseEntity.badRequest().build();
+        }
+        return openAiService.formatMarkdown(text)
+                .map(t -> ResponseEntity.ok(Map.of("content", t)))
+                .orElse(ResponseEntity.status(500).build());
+    }
+}

src/main/java/com/openisle/service/OpenAiService.java

@@ -0,0 +1,65 @@
+package com.openisle.service;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.*;
+
+@Service
+public class OpenAiService {
+
+    @Value("${openai.api-key:}")
+    private String apiKey;
+
+    @Value("${openai.model:gpt-3.5-turbo}")
+    private String model;
+
+    private final RestTemplate restTemplate = new RestTemplate();
+
+    public Optional<String> formatMarkdown(String text) {
+        if (apiKey == null || apiKey.isBlank()) {
+            return Optional.empty();
+        }
+        String url = "https://api.openai.com/v1/chat/completions";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+        headers.set("Authorization", "Bearer " + apiKey);
+
+        Map<String, Object> body = new HashMap<>();
+        body.put("model", model);
+        List<Map<String, String>> messages = new ArrayList<>();
+        messages.add(Map.of("role", "system", "content", "请优化以下 Markdown 文本的格式，不改变其内容。"));
+        messages.add(Map.of("role", "user", "content", text));
+        body.put("messages", messages);
+
+        HttpEntity<Map<String, Object>> entity = new HttpEntity<>(body, headers);
+        try {
+            ResponseEntity<Map> resp = restTemplate.exchange(url, HttpMethod.POST, entity, Map.class);
+            Map respBody = resp.getBody();
+            if (respBody != null) {
+                Object choicesObj = respBody.get("choices");
+                if (choicesObj instanceof List choices && !choices.isEmpty()) {
+                    Object first = choices.get(0);
+                    if (first instanceof Map firstMap) {
+                        Object messageObj = firstMap.get("message");
+                        if (messageObj instanceof Map message) {
+                            Object content = message.get("content");
+                            if (content instanceof String str) {
+                                return Optional.of(str.trim());
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception ignored) {
+        }
+        return Optional.empty();
+    }
+}