Fix bottom anchoring and Claude wake routing

packages/app/src/components/agent-stream-web-virtualization.ts

@@ -0,0 +1,94 @@
+import type { StreamItem } from "@/types/stream";
+
+export const DEFAULT_WEB_PARTIAL_VIRTUALIZATION_THRESHOLD = 100;
+export const DEFAULT_WEB_MOUNTED_RECENT_STREAM_ITEMS = 50;
+
+type BottomAnchorE2ETestGlobals = typeof globalThis & {
+  __PASEO_E2E_WEB_PARTIAL_VIRTUALIZATION_THRESHOLD?: unknown;
+  __PASEO_E2E_WEB_MOUNTED_RECENT_STREAM_ITEMS?: unknown;
+};
+
+function readPositiveIntegerOverride(value: unknown): number | null {
+  if (!Number.isFinite(value)) {
+    return null;
+  }
+  const normalized = Math.trunc(value as number);
+  return normalized > 0 ? normalized : null;
+}
+
+export function getWebPartialVirtualizationThreshold(): number {
+  const override = readPositiveIntegerOverride(
+    (globalThis as BottomAnchorE2ETestGlobals)
+      .__PASEO_E2E_WEB_PARTIAL_VIRTUALIZATION_THRESHOLD
+  );
+  return override ?? DEFAULT_WEB_PARTIAL_VIRTUALIZATION_THRESHOLD;
+}
+
+export function getWebMountedRecentStreamItems(): number {
+  const override = readPositiveIntegerOverride(
+    (globalThis as BottomAnchorE2ETestGlobals)
+      .__PASEO_E2E_WEB_MOUNTED_RECENT_STREAM_ITEMS
+  );
+  return override ?? DEFAULT_WEB_MOUNTED_RECENT_STREAM_ITEMS;
+}
+
+export type IndexedStreamItem = {
+  item: StreamItem;
+  index: number;
+};
+
+export type WebVirtualizedHistoryWindow = {
+  virtualizedEntries: IndexedStreamItem[];
+  mountedEntries: IndexedStreamItem[];
+};
+
+export function estimateStreamItemHeight(item: StreamItem): number {
+  switch (item.kind) {
+    case "user_message":
+      return item.images && item.images.length > 0 ? 220 : 96;
+    case "assistant_message":
+      return 220;
+    case "tool_call":
+      return 136;
+    case "thought":
+      return 112;
+    case "todo_list":
+      return 144;
+    case "activity_log":
+      return 88;
+    case "compaction":
+      return 72;
+    default:
+      return 120;
+  }
+}
+
+export function findMountedWindowStart(input: {
+  items: StreamItem[];
+  minMountedCount: number;
+}): number {
+  const { items, minMountedCount } = input;
+  if (items.length <= minMountedCount) {
+    return 0;
+  }
+
+  let startIndex = Math.max(items.length - minMountedCount, 0);
+  while (startIndex > 0 && items[startIndex]?.kind !== "user_message") {
+    startIndex -= 1;
+  }
+  return startIndex;
+}
+
+export function splitWebVirtualizedHistory(input: {
+  entries: IndexedStreamItem[];
+  minMountedCount: number;
+}): WebVirtualizedHistoryWindow {
+  const startIndex = findMountedWindowStart({
+    items: input.entries.map((entry) => entry.item),
+    minMountedCount: input.minMountedCount,
+  });
+  return {
+    virtualizedEntries: input.entries.slice(0, startIndex),
+    mountedEntries: input.entries.slice(startIndex),
+  };
+}