Initial import NDC_1C

llm_normalizer/backend/src/services/assistantSessionStore.ts

@@ -0,0 +1,98 @@
+import { nanoid } from "nanoid";
+import type { AssistantConversationItem, AssistantSessionState } from "../types/assistant";
+import type { InvestigationState } from "../types/stage1Contracts";
+import { FEATURE_ASSISTANT_INVESTIGATION_STATE_V1 } from "../config";
+import { cloneInvestigationState, createEmptyInvestigationState } from "./investigationState";
+
+const MAX_ITEMS_PER_SESSION = 200;
+
+function cloneItem(item: AssistantConversationItem): AssistantConversationItem {
+  return {
+    ...item,
+    debug: item.debug ? { ...item.debug } : null
+  };
+}
+
+function cloneSession(state: AssistantSessionState): AssistantSessionState {
+  return {
+    session_id: state.session_id,
+    updated_at: state.updated_at,
+    items: state.items.map(cloneItem),
+    investigation_state: cloneInvestigationState(state.investigation_state)
+  };
+}
+
+function normalizeSessionShape(state: AssistantSessionState): AssistantSessionState {
+  const legacy = state as AssistantSessionState & {
+    investigation_state?: InvestigationState | null;
+    items?: AssistantConversationItem[];
+    updated_at?: string;
+  };
+  const normalizedItems = Array.isArray(legacy.items) ? legacy.items : [];
+  const investigationState =
+    FEATURE_ASSISTANT_INVESTIGATION_STATE_V1
+      ? legacy.investigation_state ?? createEmptyInvestigationState(state.session_id)
+      : legacy.investigation_state ?? null;
+
+  state.items = normalizedItems;
+  state.updated_at = typeof legacy.updated_at === "string" && legacy.updated_at.trim() ? legacy.updated_at : new Date().toISOString();
+  state.investigation_state = investigationState;
+  return state;
+}
+
+export class AssistantSessionStore {
+  private readonly sessions = new Map<string, AssistantSessionState>();
+
+  public ensureSession(sessionId?: string): AssistantSessionState {
+    const resolvedId = (sessionId ?? "").trim() || `asst-${nanoid(10)}`;
+    const existing = this.sessions.get(resolvedId);
+    if (existing) {
+      return cloneSession(normalizeSessionShape(existing));
+    }
+    const created: AssistantSessionState = {
+      session_id: resolvedId,
+      updated_at: new Date().toISOString(),
+      items: [],
+      investigation_state: FEATURE_ASSISTANT_INVESTIGATION_STATE_V1 ? createEmptyInvestigationState(resolvedId) : null
+    };
+    this.sessions.set(resolvedId, created);
+    return cloneSession(created);
+  }
+
+  public appendItem(sessionId: string, item: AssistantConversationItem): AssistantConversationItem {
+    const session = this.ensureMutableSession(sessionId);
+    session.items.push(item);
+    if (session.items.length > MAX_ITEMS_PER_SESSION) {
+      session.items = session.items.slice(session.items.length - MAX_ITEMS_PER_SESSION);
+    }
+    session.updated_at = new Date().toISOString();
+    return cloneItem(item);
+  }
+
+  public getSession(sessionId: string): AssistantSessionState | null {
+    const found = this.sessions.get(sessionId);
+    return found ? cloneSession(normalizeSessionShape(found)) : null;
+  }
+
+  public setInvestigationState(sessionId: string, state: InvestigationState | null): InvestigationState | null {
+    const session = this.ensureMutableSession(sessionId);
+    session.investigation_state = cloneInvestigationState(state);
+    session.updated_at = new Date().toISOString();
+    return cloneInvestigationState(session.investigation_state);
+  }
+
+  private ensureMutableSession(sessionId: string): AssistantSessionState {
+    const existing = this.sessions.get(sessionId);
+    if (existing) {
+      return normalizeSessionShape(existing);
+    }
+    const created: AssistantSessionState = {
+      session_id: sessionId,
+      updated_at: new Date().toISOString(),
+      items: [],
+      investigation_state: FEATURE_ASSISTANT_INVESTIGATION_STATE_V1 ? createEmptyInvestigationState(sessionId) : null
+    };
+    this.sessions.set(sessionId, created);
+    return created;
+  }
+}