src/plugin-sdk/allow-from.ts

export function formatAllowFromLowercase(params: {
  allowFrom: Array<string | number>;
  stripPrefixRe?: RegExp;
}): string[] {
  return params.allowFrom
    .map((entry) => String(entry).trim())
    .filter(Boolean)
    .map((entry) => (params.stripPrefixRe ? entry.replace(params.stripPrefixRe, "") : entry))
    .map((entry) => entry.toLowerCase());
}

export function formatNormalizedAllowFromEntries(params: {
  allowFrom: Array<string | number>;
  normalizeEntry: (entry: string) => string | undefined | null;
}): string[] {
  return params.allowFrom
    .map((entry) => String(entry).trim())
    .filter(Boolean)
    .map((entry) => params.normalizeEntry(entry))
    .filter((entry): entry is string => Boolean(entry));
}

export function isNormalizedSenderAllowed(params: {
  senderId: string | number;
  allowFrom: Array<string | number>;
  stripPrefixRe?: RegExp;
}): boolean {
  const normalizedAllow = formatAllowFromLowercase({
    allowFrom: params.allowFrom,
    stripPrefixRe: params.stripPrefixRe,
  });
  if (normalizedAllow.length === 0) {
    return false;
  }
  if (normalizedAllow.includes("*")) {
    return true;
  }
  const sender = String(params.senderId).trim().toLowerCase();
  return normalizedAllow.includes(sender);
}

type ParsedChatAllowTarget =
  | { kind: "chat_id"; chatId: number }
  | { kind: "chat_guid"; chatGuid: string }
  | { kind: "chat_identifier"; chatIdentifier: string }
  | { kind: "handle"; handle: string };

export function isAllowedParsedChatSender<TParsed extends ParsedChatAllowTarget>(params: {
  allowFrom: Array<string | number>;
  sender: string;
  chatId?: number | null;
  chatGuid?: string | null;
  chatIdentifier?: string | null;
  normalizeSender: (sender: string) => string;
  parseAllowTarget: (entry: string) => TParsed;
}): boolean {
  const allowFrom = params.allowFrom.map((entry) => String(entry).trim());
  if (allowFrom.length === 0) {
    return false;
  }
  if (allowFrom.includes("*")) {
    return true;
  }

  const senderNormalized = params.normalizeSender(params.sender);
  const chatId = params.chatId ?? undefined;
  const chatGuid = params.chatGuid?.trim();
  const chatIdentifier = params.chatIdentifier?.trim();

  for (const entry of allowFrom) {
    if (!entry) {
      continue;
    }
    const parsed = params.parseAllowTarget(entry);
    if (parsed.kind === "chat_id" && chatId !== undefined) {
      if (parsed.chatId === chatId) {
        return true;
      }
    } else if (parsed.kind === "chat_guid" && chatGuid) {
      if (parsed.chatGuid === chatGuid) {
        return true;
      }
    } else if (parsed.kind === "chat_identifier" && chatIdentifier) {
      if (parsed.chatIdentifier === chatIdentifier) {
        return true;
      }
    } else if (parsed.kind === "handle" && senderNormalized) {
      if (parsed.handle === senderNormalized) {
        return true;
      }
    }
  }
  return false;
}