stable POC version 1 - chat and topics

backend/src/main/java/com/aiteacher/chat/ChatController.java

@@ -32,6 +32,21 @@ public class ChatController {
         return ResponseEntity.status(HttpStatus.CREATED).body(response);
     }
 
+    @GetMapping("/sessions")
+    public ResponseEntity<List<Map<String, Object>>> getSessionsByTopic(@RequestParam String topicId) {
+        List<ChatSession> sessions = chatService.getSessionsByTopic(topicId);
+        List<Map<String, Object>> response = sessions.stream()
+            .map(s -> {
+                Map<String, Object> m = new LinkedHashMap<>();
+                m.put("sessionId", s.getId());
+                m.put("topicId", s.getTopicId());
+                m.put("createdAt", s.getCreatedAt());
+                return m;
+            })
+            .toList();
+        return ResponseEntity.ok(response);
+    }
+
     @GetMapping("/sessions/{sessionId}/messages")
     public ResponseEntity<List<Map<String, Object>>> getMessages(@PathVariable UUID sessionId) {
         List<Message> messages = chatService.getMessages(sessionId);

backend/src/main/java/com/aiteacher/chat/ChatService.java

@@ -26,17 +26,18 @@ public class ChatService {
     private static final Logger log = LoggerFactory.getLogger(ChatService.class);
 
     private static final String SYSTEM_PROMPT = """
-        You are an expert neurosurgery educator assistant. Your role is to answer
-        questions based ONLY on the content from uploaded medical textbooks that has been
-        retrieved for you as context.
+        You are an expert neurosurgery educator assistant. Answer questions using the
+        medical textbook content provided to you as context.
 
         Rules:
-        - Answer only from the provided context chunks
-        - If the context does not contain enough information, explicitly state:
-          "I could not find relevant information about this topic in the uploaded books."
-        - Cite sources when possible (book title and page number from the context metadata)
+        - Give comprehensive, detailed answers — cover all relevant aspects found in the context: anatomy, indications, contraindications, techniques, procedural steps, complications, outcomes, and clinical considerations
+        - When the context contains related information, synthesize a thorough answer from it — do not apologize for missing definitions or lead with what you couldn't find
+        - Build answers from what is present: procedures, conditions, techniques, and descriptions all contribute; combine them into a rich, structured response
+        - Use clear structure: headings, bullet points, or numbered steps where appropriate to maximize clarity
+        - Only say you cannot answer if the context is entirely unrelated to the question
+        - Cite sources for each major point (book title and page number from the context metadata)
         - Maintain continuity with the conversation history
-        - Never fabricate clinical information
+        - Never fabricate clinical information not present in the context
         """;
 
     private final ChatClient chatClient;
@@ -87,7 +88,7 @@ public class ChatService {
         String fullQuestion = buildQuestionWithHistory(history, userContent, session.getTopicId());
 
         var qaAdvisor = QuestionAnswerAdvisor.builder(vectorStore)
-        .searchRequest(SearchRequest.builder().similarityThreshold(0.8d).topK(6).build())
+        .searchRequest(SearchRequest.builder().similarityThreshold(0.5d).topK(6).build())
         .build();
         
         ChatResponse response = chatClient.prompt()
@@ -106,6 +107,10 @@ public class ChatService {
         return messageRepository.save(assistantMessage);
     }
 
+    public List<ChatSession> getSessionsByTopic(String topicId) {
+        return sessionRepository.findByTopicIdOrderByCreatedAtDesc(topicId);
+    }
+
     public void deleteSession(UUID sessionId) {
         if (!sessionRepository.existsById(sessionId)) {
             throw new NoSuchElementException("Session not found.");
@@ -115,16 +120,17 @@ public class ChatService {
 
     private String buildQuestionWithHistory(List<Message> history, String currentQuestion,
                                             String topicId) {
+        boolean hasTopic = topicId != null && !topicId.equals("free-form");
+
         if (history.size() <= 1) {
-            // Only the current user message is in history; just ask the question
-            return topicId != null
+            return hasTopic
                 ? String.format("[Context: This is a question about the neurosurgery topic '%s']\n%s",
                     topicId, currentQuestion)
                 : currentQuestion;
         }
 
         StringBuilder sb = new StringBuilder();
-        if (topicId != null) {
+        if (hasTopic) {
             sb.append(String.format("[Context: This conversation is about the neurosurgery topic '%s']\n\n",
                 topicId));
         }
@@ -154,6 +160,7 @@ public class ChatService {
                             Map<String, Object> source = new HashMap<>();
                             source.put("bookTitle", bookTitle);
                             source.put("page", page);
+                            source.put("chunkText", doc.getText());
                             sources.add(source);
                         }
                     }

backend/src/main/java/com/aiteacher/chat/ChatSessionRepository.java

@@ -3,8 +3,10 @@ package com.aiteacher.chat;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
+import java.util.List;
 import java.util.UUID;
 
 @Repository
 public interface ChatSessionRepository extends JpaRepository<ChatSession, UUID> {
+    List<ChatSession> findByTopicIdOrderByCreatedAtDesc(String topicId);
 }