refactor(signal): normalize sender identity

src/signal/identity.ts

@@ -0,0 +1,114 @@
+import { normalizeE164 } from "../utils.js";
+
+export type SignalSender =
+  | { kind: "phone"; raw: string; e164: string }
+  | { kind: "uuid"; raw: string };
+
+type SignalAllowEntry =
+  | { kind: "any" }
+  | { kind: "phone"; e164: string }
+  | { kind: "uuid"; raw: string };
+
+const UUID_HYPHENATED_RE =
+  /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+const UUID_COMPACT_RE = /^[0-9a-f]{32}$/i;
+
+function looksLikeUuid(value: string): boolean {
+  if (UUID_HYPHENATED_RE.test(value) || UUID_COMPACT_RE.test(value)) {
+    return true;
+  }
+  const compact = value.replace(/-/g, "");
+  if (!/^[0-9a-f]+$/i.test(compact)) return false;
+  return /[a-f]/i.test(compact);
+}
+
+function stripSignalPrefix(value: string): string {
+  return value.replace(/^signal:/i, "").trim();
+}
+
+export function resolveSignalSender(params: {
+  sourceNumber?: string | null;
+  sourceUuid?: string | null;
+}): SignalSender | null {
+  const sourceNumber = params.sourceNumber?.trim();
+  if (sourceNumber) {
+    return {
+      kind: "phone",
+      raw: sourceNumber,
+      e164: normalizeE164(sourceNumber),
+    };
+  }
+  const sourceUuid = params.sourceUuid?.trim();
+  if (sourceUuid) {
+    return { kind: "uuid", raw: sourceUuid };
+  }
+  return null;
+}
+
+export function formatSignalSenderId(sender: SignalSender): string {
+  return sender.kind === "phone" ? sender.e164 : `uuid:${sender.raw}`;
+}
+
+export function formatSignalSenderDisplay(sender: SignalSender): string {
+  return sender.kind === "phone" ? sender.e164 : `uuid:${sender.raw}`;
+}
+
+export function resolveSignalRecipient(sender: SignalSender): string {
+  return sender.kind === "phone" ? sender.e164 : sender.raw;
+}
+
+export function resolveSignalPeerId(sender: SignalSender): string {
+  return sender.kind === "phone" ? sender.e164 : `uuid:${sender.raw}`;
+}
+
+function parseSignalAllowEntry(entry: string): SignalAllowEntry | null {
+  const trimmed = entry.trim();
+  if (!trimmed) return null;
+  if (trimmed === "*") return { kind: "any" };
+
+  const stripped = stripSignalPrefix(trimmed);
+  const lower = stripped.toLowerCase();
+  if (lower.startsWith("uuid:")) {
+    const raw = stripped.slice("uuid:".length).trim();
+    if (!raw) return null;
+    return { kind: "uuid", raw };
+  }
+
+  if (looksLikeUuid(stripped)) {
+    return { kind: "uuid", raw: stripped };
+  }
+
+  return { kind: "phone", e164: normalizeE164(stripped) };
+}
+
+export function isSignalSenderAllowed(
+  sender: SignalSender,
+  allowFrom: string[],
+): boolean {
+  if (allowFrom.length === 0) return false;
+  const parsed = allowFrom
+    .map(parseSignalAllowEntry)
+    .filter((entry): entry is SignalAllowEntry => entry !== null);
+  if (parsed.some((entry) => entry.kind === "any")) return true;
+  return parsed.some((entry) => {
+    if (entry.kind === "phone" && sender.kind === "phone") {
+      return entry.e164 === sender.e164;
+    }
+    if (entry.kind === "uuid" && sender.kind === "uuid") {
+      return entry.raw === sender.raw;
+    }
+    return false;
+  });
+}
+
+export function isSignalGroupAllowed(params: {
+  groupPolicy: "open" | "disabled" | "allowlist";
+  allowFrom: string[];
+  sender: SignalSender;
+}): boolean {
+  const { groupPolicy, allowFrom, sender } = params;
+  if (groupPolicy === "disabled") return false;
+  if (groupPolicy === "open") return true;
+  if (allowFrom.length === 0) return false;
+  return isSignalSenderAllowed(sender, allowFrom);
+}