feat: unify provider history context

src/auto-reply/reply/history.ts

@@ -0,0 +1,64 @@
+import { CURRENT_MESSAGE_MARKER } from "./mentions.js";
+
+export const HISTORY_CONTEXT_MARKER =
+  "[Chat messages since your last reply - for context]";
+export const DEFAULT_GROUP_HISTORY_LIMIT = 50;
+
+export type HistoryEntry = {
+  sender: string;
+  body: string;
+  timestamp?: number;
+  messageId?: string;
+};
+
+export function buildHistoryContext(params: {
+  historyText: string;
+  currentMessage: string;
+  lineBreak?: string;
+}): string {
+  const { historyText, currentMessage } = params;
+  const lineBreak = params.lineBreak ?? "\n";
+  if (!historyText.trim()) return currentMessage;
+  return [
+    HISTORY_CONTEXT_MARKER,
+    historyText,
+    "",
+    CURRENT_MESSAGE_MARKER,
+    currentMessage,
+  ].join(lineBreak);
+}
+
+export function appendHistoryEntry(params: {
+  historyMap: Map<string, HistoryEntry[]>;
+  historyKey: string;
+  entry: HistoryEntry;
+  limit: number;
+}): HistoryEntry[] {
+  const { historyMap, historyKey, entry } = params;
+  if (params.limit <= 0) return [];
+  const history = historyMap.get(historyKey) ?? [];
+  history.push(entry);
+  while (history.length > params.limit) history.shift();
+  historyMap.set(historyKey, history);
+  return history;
+}
+
+export function buildHistoryContextFromEntries(params: {
+  entries: HistoryEntry[];
+  currentMessage: string;
+  formatEntry: (entry: HistoryEntry) => string;
+  lineBreak?: string;
+  excludeLast?: boolean;
+}): string {
+  const lineBreak = params.lineBreak ?? "\n";
+  const entries = params.excludeLast === false
+    ? params.entries
+    : params.entries.slice(0, -1);
+  if (entries.length === 0) return params.currentMessage;
+  const historyText = entries.map(params.formatEntry).join(lineBreak);
+  return buildHistoryContext({
+    historyText,
+    currentMessage: params.currentMessage,
+    lineBreak,
+  });
+}