src/channels/plugins/normalize/imessage.ts

import { normalizeIMessageHandle } from "../../../imessage/targets.js";

// Service prefixes that indicate explicit delivery method; must be preserved during normalization
const SERVICE_PREFIXES = ["imessage:", "sms:", "auto:"] as const;
const CHAT_TARGET_PREFIX_RE =
  /^(chat_id:|chatid:|chat:|chat_guid:|chatguid:|guid:|chat_identifier:|chatidentifier:|chatident:)/i;

export function normalizeIMessageMessagingTarget(raw: string): string | undefined {
  const trimmed = raw.trim();
  if (!trimmed) return undefined;

  // Preserve service prefix if present (e.g., "sms:+1555" → "sms:+15551234567")
  const lower = trimmed.toLowerCase();
  for (const prefix of SERVICE_PREFIXES) {
    if (lower.startsWith(prefix)) {
      const remainder = trimmed.slice(prefix.length).trim();
      const normalizedHandle = normalizeIMessageHandle(remainder);
      if (!normalizedHandle) return undefined;
      if (CHAT_TARGET_PREFIX_RE.test(normalizedHandle)) return normalizedHandle;
      return `${prefix}${normalizedHandle}`;
    }
  }

  const normalized = normalizeIMessageHandle(trimmed);
  return normalized || undefined;
}

export function looksLikeIMessageTargetId(raw: string): boolean {
  const trimmed = raw.trim();
  if (!trimmed) return false;
  if (/^(imessage:|sms:|auto:)/i.test(trimmed)) return true;
  if (CHAT_TARGET_PREFIX_RE.test(trimmed)) return true;
  if (trimmed.includes("@")) return true;
  return /^\+?\d{3,}$/.test(trimmed);
}