[Init] Initial commit - NetMesh terminal manager

components/ai/scopedHistorySessions.ts

@@ -0,0 +1,95 @@
+import type { AISession } from '../../infrastructure/ai/types';
+import { getSessionScopeMatchRank } from './sessionScopeMatch';
+
+type HistoryCacheKey = string;
+const MAX_HISTORY_CACHE_ENTRIES_PER_SESSION_LIST = 64;
+const historyCache = new WeakMap<AISession[], Map<HistoryCacheKey, AISession[]>>();
+
+function buildHistoryCacheKey(
+  scopeType: 'terminal' | 'workspace',
+  scopeTargetId: string | undefined,
+  scopeHostIds: string[] | undefined,
+  activeTerminalSessionIds: Set<string>,
+  workspaceMemberTerminalIds: Set<string> | undefined,
+  workspaceMemberActiveSessionIds: Set<string>,
+): HistoryCacheKey {
+  const hostKey = scopeHostIds ? [...scopeHostIds].sort().join(',') : '';
+  const terminalKey = scopeType === 'terminal'
+    ? [...activeTerminalSessionIds].sort().join(',')
+    : '';
+  const memberKey = scopeType === 'workspace' && workspaceMemberTerminalIds
+    ? [...workspaceMemberTerminalIds].sort().join(',')
+    : '';
+  const memberActiveKey = [...workspaceMemberActiveSessionIds].sort().join(',');
+  return `${scopeType}:${scopeTargetId ?? ''}:${hostKey}:${terminalKey}:${memberKey}:${memberActiveKey}`;
+}
+
+export function getScopedHistorySessions(
+  sessions: AISession[],
+  scopeType: 'terminal' | 'workspace',
+  scopeTargetId: string | undefined,
+  scopeHostIds: string[] | undefined,
+  activeTerminalSessionIds: Set<string>,
+  workspaceMemberTerminalIds?: Set<string>,
+  activeSessionIdMap?: Readonly<Record<string, string | null | undefined>>,
+): AISession[] {
+  // A member can be continuing history created on an older terminal. Its
+  // selected chat belongs in workspace history even though scope.targetId
+  // still identifies that older terminal. Do not include nonmember selections.
+  const workspaceMemberActiveSessionIds = new Set<string>();
+  if (scopeType === 'workspace' && workspaceMemberTerminalIds && activeSessionIdMap) {
+    for (const terminalId of workspaceMemberTerminalIds) {
+      const sessionId = activeSessionIdMap[`terminal:${terminalId}`];
+      if (sessionId) workspaceMemberActiveSessionIds.add(sessionId);
+    }
+  }
+  let scopeCache = historyCache.get(sessions);
+  if (!scopeCache) {
+    scopeCache = new Map();
+    historyCache.set(sessions, scopeCache);
+  }
+
+  const cacheKey = buildHistoryCacheKey(
+    scopeType,
+    scopeTargetId,
+    scopeHostIds,
+    activeTerminalSessionIds,
+    workspaceMemberTerminalIds,
+    workspaceMemberActiveSessionIds,
+  );
+  const cached = scopeCache.get(cacheKey);
+  if (cached) {
+    scopeCache.delete(cacheKey);
+    scopeCache.set(cacheKey, cached);
+    return cached;
+  }
+
+  const result = sessions
+    .map((session) => ({
+      session,
+      matchRank: getSessionScopeMatchRank(
+        session,
+        scopeType,
+        scopeTargetId,
+        scopeHostIds,
+        activeTerminalSessionIds,
+        workspaceMemberTerminalIds,
+        workspaceMemberActiveSessionIds,
+      ),
+    }))
+    .filter(({ matchRank }) => matchRank > 0)
+    .sort((a, b) => b.matchRank - a.matchRank || b.session.updatedAt - a.session.updatedAt)
+    .map(({ session }) => session);
+
+  scopeCache.set(cacheKey, result);
+  while (scopeCache.size > MAX_HISTORY_CACHE_ENTRIES_PER_SESSION_LIST) {
+    const oldestKey = scopeCache.keys().next().value;
+    if (oldestKey == null) break;
+    scopeCache.delete(oldestKey);
+  }
+  return result;
+}
+
+export function _getScopedHistoryCacheSizeForTests(sessions: AISession[]): number {
+  return historyCache.get(sessions)?.size ?? 0;
+}