Add support for message history pagination, preserve scroll in rendering, and improve draft/message workflows.

src/routes/chats.js

@@ -217,10 +217,39 @@ export function createChatsRouter({repositories, chatService, modelService, conf
         const chatId = Number(req.params.id);
         const chat = repositories.getChat(chatId, req.session.user);
         if (!chat) return res.status(404).json({error: "Chat not found"});
-        return res.json({
-            messages: chatService.listActiveBranchMessages(chatId),
-            chat
-        });
+        const options = {};
+        for (const key of ["limit", "before", "leaf", "around"]) {
+            if (req.query[key] === undefined) continue;
+            const value = Number(req.query[key]);
+            if (!Number.isSafeInteger(value) || value < 1 || (key === "limit" && value > 100)) {
+                return res.status(400).json({error: `Invalid history ${key}`});
+            }
+            options[key] = value;
+        }
+        const result = chatService.getHistoryPage(chatId, options);
+        if (result.error) return res.status(result.status).json(result);
+        return res.json({...result, chat});
+    });
+
+    router.get("/chats/:id/branches", (req, res) => {
+        const chatId = Number(req.params.id);
+        const chat = repositories.getChat(chatId, req.session.user);
+        if (!chat) return res.status(404).json({error: "Chat not found"});
+        const after = Number(req.query.after || 0);
+        if (!Number.isSafeInteger(after) || after < 0) return res.status(400).json({error: "Invalid branch cursor"});
+        const nodes = repositories.listBranchNodes(chatId, {after});
+        const hasMore = nodes.length > 200;
+        if (hasMore) nodes.pop();
+        return res.json({nodes, activeLeafId: chat.active_leaf_message_id || nodes.at(-1)?.id || null,
+            next: hasMore ? nodes.at(-1).id : null});
+    });
+
+    router.get("/chats/:id/messages/:messageId/versions", (req, res) => {
+        const chatId = Number(req.params.id);
+        if (!repositories.getChat(chatId, req.session.user)) return res.status(404).json({error: "Chat not found"});
+        const message = repositories.getChatMessage(chatId, Number(req.params.messageId));
+        if (!message) return res.status(404).json({error: "Message not found"});
+        return res.json({message: chatService.formatChatMessage(message)});
     });
 
     router.put("/chats/:id/generation-settings", validateBody(generationSettingsValidator), (req, res) => {
@@ -406,7 +435,26 @@ export function createChatsRouter({repositories, chatService, modelService, conf
         const chatId = Number(req.params.id);
         const chat = repositories.getChat(chatId, req.session.user);
         if (!chat) return res.status(404).json({error: "Chat not found"});
-        return res.json({memories: repositories.listChatMemories(chatId, req.session.user)});
+        const payload = chatService.buildMessagesPayload({user: req.session.user, chatId, session: chat});
+        const characters = payload.messagesPayload.reduce((total, message) => total + String(message.content || "").length, 0);
+        return res.json({memories: repositories.listChatMemories(chatId, req.session.user), summary: chat.context_summary || "",
+            summaryMessageId: chat.context_summary_message_id || 0, summaryMaxChars: config.chatSummaryMaxChars,
+            context: {estimatedTokens: Math.ceil(characters / 4), contextLength: chat.context_length || null,
+                recentMessageLimit: config.chatHistoryLimit, memoryFactLimit: 30}});
+    });
+
+    router.put("/chats/:id/summary", (req, res) => {
+        const chatId = Number(req.params.id);
+        const chat = repositories.getChat(chatId, req.session.user);
+        if (!chat) return res.status(404).json({error: "Chat not found"});
+        if (chatService.isGenerating(chatId)) return res.status(409).json({error: "Wait for the response to finish before editing its summary."});
+        const summary = req.body?.summary;
+        if (typeof summary !== "string" || summary.length > config.chatSummaryMaxChars) {
+            return res.status(400).json({error: `Summary must be text of at most ${config.chatSummaryMaxChars} characters.`});
+        }
+        if (req.body.previousSummary !== (chat.context_summary || "")) return res.status(409).json({error: "The summary changed. Reopen memory to review it before saving."});
+        repositories.updateChatContextSummary(chatId, req.session.user, summary.trim() || null, chat.context_summary_message_id);
+        return res.json({summary: summary.trim()});
     });
 
     router.post("/chats/:id/memories", validateBody(memoryValidator), (req, res) => {