feat(odin): conversation-scoped service + routes (replace /history)

Remove single-thread getChatHistory/appendChatMessages/clearChatHistory and the
three /history routes; add listConversations, createConversation, getConversation-
Messages, appendConversationMessages, renameConversation, deleteConversation with
ownership checks and auto-title; wire six /conversations[/:id] routes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/admin/ai.ts

@@ -1,12 +1,14 @@
 import { FastifyInstance, FastifyRequest, FastifyReply } from "fastify";
 import multipart from "@fastify/multipart";
 import { requirePermission } from "../../middleware/auth";
-import { success, error } from "../../utils/response";
+import { success, error, parseId } from "../../utils/response";
 import { parseBody } from "../../schemas/common";
 import {
   AiChatSchema,
   AiBudgetSchema,
   AiHistoryAppendSchema,
+  AiCreateConversationSchema,
+  AiRenameConversationSchema,
 } from "../../schemas/ai.schema";
 import { logAudit } from "../../services/audit";
 import { config } from "../../config/env";
@@ -18,9 +20,12 @@ import {
   setBudgetUsd,
   chat,
   extractInvoice,
-  getChatHistory,
-  appendChatMessages,
-  clearChatHistory,
+  listConversations,
+  createConversation,
+  getConversationMessages,
+  appendConversationMessages,
+  renameConversation,
+  deleteConversation,
   type ExtractedInvoice,
 } from "../../services/ai.service";
 
@@ -131,35 +136,95 @@ export default async function aiRoutes(app: FastifyInstance): Promise<void> {
     },
   );
 
-  // GET /api/admin/ai/history — this user's stored chat thread
+  // GET /conversations — this user's conversations (stable order)
   app.get(
-    "/history",
+    "/conversations",
     { preHandler: requirePermission("ai.use") },
     async (request: FastifyRequest, reply: FastifyReply) => {
-      const messages = await getChatHistory(request.authData!.userId);
-      return success(reply, { messages });
+      const conversations = await listConversations(request.authData!.userId);
+      return success(reply, { conversations });
     },
   );
 
-  // POST /api/admin/ai/history — append turns to this user's thread
+  // POST /conversations — create
   app.post(
-    "/history",
+    "/conversations",
     { preHandler: requirePermission("ai.use") },
     async (request: FastifyRequest, reply: FastifyReply) => {
+      const body = parseBody(AiCreateConversationSchema, request.body);
+      if ("error" in body) return error(reply, body.error, 400);
+      const conversation = await createConversation(
+        request.authData!.userId,
+        body.data.title,
+      );
+      return success(reply, { conversation });
+    },
+  );
+
+  // GET /conversations/:id/messages
+  app.get(
+    "/conversations/:id/messages",
+    { preHandler: requirePermission("ai.use") },
+    async (request: FastifyRequest, reply: FastifyReply) => {
+      const id = parseId((request.params as { id: string }).id, reply);
+      if (id === null) return;
+      const result = await getConversationMessages(
+        request.authData!.userId,
+        id,
+      );
+      if ("error" in result) return error(reply, result.error, result.status);
+      return success(reply, { messages: result.data });
+    },
+  );
+
+  // POST /conversations/:id/messages — append turns
+  app.post(
+    "/conversations/:id/messages",
+    { preHandler: requirePermission("ai.use") },
+    async (request: FastifyRequest, reply: FastifyReply) => {
+      const id = parseId((request.params as { id: string }).id, reply);
+      if (id === null) return;
       const body = parseBody(AiHistoryAppendSchema, request.body);
       if ("error" in body) return error(reply, body.error, 400);
-      await appendChatMessages(request.authData!.userId, body.data.messages);
-      return success(reply, { ok: true });
+      const result = await appendConversationMessages(
+        request.authData!.userId,
+        id,
+        body.data.messages,
+      );
+      if ("error" in result) return error(reply, result.error, result.status);
+      return success(reply, result.data);
     },
   );
 
-  // DELETE /api/admin/ai/history — clear this user's thread
-  app.delete(
-    "/history",
+  // PATCH /conversations/:id — rename
+  app.patch(
+    "/conversations/:id",
     { preHandler: requirePermission("ai.use") },
     async (request: FastifyRequest, reply: FastifyReply) => {
-      await clearChatHistory(request.authData!.userId);
-      return success(reply, { ok: true });
+      const id = parseId((request.params as { id: string }).id, reply);
+      if (id === null) return;
+      const body = parseBody(AiRenameConversationSchema, request.body);
+      if ("error" in body) return error(reply, body.error, 400);
+      const result = await renameConversation(
+        request.authData!.userId,
+        id,
+        body.data.title,
+      );
+      if ("error" in result) return error(reply, result.error, result.status);
+      return success(reply, { conversation: result.data });
+    },
+  );
+
+  // DELETE /conversations/:id
+  app.delete(
+    "/conversations/:id",
+    { preHandler: requirePermission("ai.use") },
+    async (request: FastifyRequest, reply: FastifyReply) => {
+      const id = parseId((request.params as { id: string }).id, reply);
+      if (id === null) return;
+      const result = await deleteConversation(request.authData!.userId, id);
+      if ("error" in result) return error(reply, result.error, result.status);
+      return success(reply, result.data);
     },
   );
 }

src/schemas/ai.schema.ts

@@ -24,6 +24,14 @@ export const AiHistoryAppendSchema = z.object({
     .max(20, "Příliš mnoho zpráv"),
 });
 
+export const AiCreateConversationSchema = z.object({
+  title: z.string().max(255).optional(),
+});
+
+export const AiRenameConversationSchema = z.object({
+  title: z.string().min(1, "Název je povinný").max(255),
+});
+
 export const AiBudgetSchema = z.object({
   budget_usd: z
     .union([z.number(), z.string()])

src/services/ai.service.ts

@@ -104,48 +104,121 @@ export async function assertBudgetAvailable(): Promise<{
   return null;
 }
 
-// ── Chat history (server-side, permanent, per user) ───────────────────────
+// ── Conversations (server-side, per user) ─────────────────────────────────
 export interface StoredChatMessage {
   role: string;
   content: string;
   created_at: Date;
 }
+export interface ConversationSummary {
+  id: number;
+  title: string;
+  updated_at: Date;
+}
 
-// Cap how many turns we read back / display. The full thread stays in the DB;
-// this only bounds a single GET payload (and, on the client, the model context).
-const HISTORY_LIMIT = 200;
+const DEFAULT_CONVERSATION_TITLE = "Nová konverzace";
+const MESSAGE_LIMIT = 200; // cap a single thread read
 
-/** This user's chat thread, oldest → newest, capped at HISTORY_LIMIT. */
-export async function getChatHistory(
+export async function listConversations(
   userId: number,
-): Promise<StoredChatMessage[]> {
-  const rows = await prisma.ai_chat_messages.findMany({
+): Promise<ConversationSummary[]> {
+  return prisma.ai_conversations.findMany({
     where: { user_id: userId },
+    orderBy: { id: "asc" }, // stable tab order
+    select: { id: true, title: true, updated_at: true },
+  });
+}
+
+export async function createConversation(
+  userId: number,
+  title?: string,
+): Promise<ConversationSummary> {
+  return prisma.ai_conversations.create({
+    data: {
+      user_id: userId,
+      title: title?.trim() || DEFAULT_CONVERSATION_TITLE,
+    },
+    select: { id: true, title: true, updated_at: true },
+  });
+}
+
+/** Ownership-checked fetch; null when not found / not owned. */
+async function ownConversation(userId: number, convId: number) {
+  return prisma.ai_conversations.findFirst({
+    where: { id: convId, user_id: userId },
+    select: { id: true, title: true },
+  });
+}
+
+export async function getConversationMessages(
+  userId: number,
+  convId: number,
+): Promise<{ data: StoredChatMessage[] } | { error: string; status: number }> {
+  if (!(await ownConversation(userId, convId)))
+    return { error: "Konverzace nenalezena", status: 404 };
+  const rows = await prisma.ai_chat_messages.findMany({
+    where: { conversation_id: convId },
     orderBy: { id: "desc" },
-    take: HISTORY_LIMIT,
+    take: MESSAGE_LIMIT,
     select: { role: true, content: true, created_at: true },
   });
-  return rows.reverse();
+  return { data: rows.reverse() };
 }
 
-/** Append turns to this user's thread (best-effort caller). */
-export async function appendChatMessages(
+export async function appendConversationMessages(
   userId: number,
+  convId: number,
   messages: { role: string; content: string }[],
-): Promise<void> {
-  if (messages.length === 0) return;
-  await prisma.ai_chat_messages.createMany({
-    data: messages.map((m) => ({
-      user_id: userId,
-      role: m.role,
-      content: m.content,
-    })),
-  });
+): Promise<{ data: { ok: true } } | { error: string; status: number }> {
+  const conv = await ownConversation(userId, convId);
+  if (!conv) return { error: "Konverzace nenalezena", status: 404 };
+  // The route validates messages with min(1), so this is normally non-empty;
+  // the guard is defensive (and still bumps updated_at below for an empty call).
+  if (messages.length > 0) {
+    await prisma.ai_chat_messages.createMany({
+      data: messages.map((m) => ({
+        user_id: userId,
+        conversation_id: convId,
+        role: m.role,
+        content: m.content,
+      })),
+    });
+  }
+  // Auto-title from the first user message (only while still the default), and
+  // always bump updated_at.
+  const firstUser = messages.find((m) => m.role === "user");
+  const data: { updated_at: Date; title?: string } = { updated_at: new Date() };
+  if (conv.title === DEFAULT_CONVERSATION_TITLE && firstUser) {
+    const t = firstUser.content.replace(/\s+/g, " ").trim().slice(0, 60);
+    if (t) data.title = t;
+  }
+  await prisma.ai_conversations.update({ where: { id: convId }, data });
+  return { data: { ok: true } };
 }
 
-/** Wipe this user's thread. */
-export async function clearChatHistory(userId: number): Promise<void> {
-  await prisma.ai_chat_messages.deleteMany({ where: { user_id: userId } });
+export async function renameConversation(
+  userId: number,
+  convId: number,
+  title: string,
+): Promise<{ data: ConversationSummary } | { error: string; status: number }> {
+  if (!(await ownConversation(userId, convId)))
+    return { error: "Konverzace nenalezena", status: 404 };
+  const updated = await prisma.ai_conversations.update({
+    where: { id: convId },
+    data: { title: title.trim() || DEFAULT_CONVERSATION_TITLE },
+    select: { id: true, title: true, updated_at: true },
+  });
+  return { data: updated };
+}
+
+export async function deleteConversation(
+  userId: number,
+  convId: number,
+): Promise<{ data: { ok: true } } | { error: string; status: number }> {
+  if (!(await ownConversation(userId, convId)))
+    return { error: "Konverzace nenalezena", status: 404 };
+  await prisma.ai_conversations.delete({ where: { id: convId } }); // cascade
+  return { data: { ok: true } };
 }
 
 export interface ChatMessage {