src/channels/sender-label.ts

export type SenderLabelParams = {
  name?: string;
  username?: string;
  tag?: string;
  e164?: string;
  id?: string;
};

function normalize(value?: string): string | undefined {
  const trimmed = value?.trim();
  return trimmed ? trimmed : undefined;
}

function normalizeSenderLabelParams(params: SenderLabelParams) {
  return {
    name: normalize(params.name),
    username: normalize(params.username),
    tag: normalize(params.tag),
    e164: normalize(params.e164),
    id: normalize(params.id),
  };
}

export function resolveSenderLabel(params: SenderLabelParams): string | null {
  const { name, username, tag, e164, id } = normalizeSenderLabelParams(params);

  const display = name ?? username ?? tag ?? "";
  const idPart = e164 ?? id ?? "";
  if (display && idPart && display !== idPart) {
    return `${display} (${idPart})`;
  }
  return display || idPart || null;
}

export function listSenderLabelCandidates(params: SenderLabelParams): string[] {
  const candidates = new Set<string>();
  const { name, username, tag, e164, id } = normalizeSenderLabelParams(params);

  if (name) {
    candidates.add(name);
  }
  if (username) {
    candidates.add(username);
  }
  if (tag) {
    candidates.add(tag);
  }
  if (e164) {
    candidates.add(e164);
  }
  if (id) {
    candidates.add(id);
  }
  const resolved = resolveSenderLabel(params);
  if (resolved) {
    candidates.add(resolved);
  }
  return Array.from(candidates);
}