refactor(telegram): split bot handlers

src/telegram/bot-access.ts

@@ -0,0 +1,48 @@
+export type NormalizedAllowFrom = {
+  entries: string[];
+  entriesLower: string[];
+  hasWildcard: boolean;
+  hasEntries: boolean;
+};
+
+export const normalizeAllowFrom = (
+  list?: Array<string | number>,
+): NormalizedAllowFrom => {
+  const entries = (list ?? [])
+    .map((value) => String(value).trim())
+    .filter(Boolean);
+  const hasWildcard = entries.includes("*");
+  const normalized = entries
+    .filter((value) => value !== "*")
+    .map((value) => value.replace(/^(telegram|tg):/i, ""));
+  const normalizedLower = normalized.map((value) => value.toLowerCase());
+  return {
+    entries: normalized,
+    entriesLower: normalizedLower,
+    hasWildcard,
+    hasEntries: entries.length > 0,
+  };
+};
+
+export const firstDefined = <T>(...values: Array<T | undefined>) => {
+  for (const value of values) {
+    if (typeof value !== "undefined") return value;
+  }
+  return undefined;
+};
+
+export const isSenderAllowed = (params: {
+  allow: NormalizedAllowFrom;
+  senderId?: string;
+  senderUsername?: string;
+}) => {
+  const { allow, senderId, senderUsername } = params;
+  if (!allow.hasEntries) return true;
+  if (allow.hasWildcard) return true;
+  if (senderId && allow.entries.includes(senderId)) return true;
+  const username = senderUsername?.toLowerCase();
+  if (!username) return false;
+  return allow.entriesLower.some(
+    (entry) => entry === username || entry === `@${username}`,
+  );
+};