// High-level wallet account operations shared by the join, recover and login
// flows. These compose the low-level primitives (derive / crypto / store) with the
// browser-native bus session so the page components stay thin.

import { bus } from "../busService";
import type { User } from "../types";
import { decryptJSON, encryptJSON } from "./crypto";
import type { WalletIdentity } from "./derive";
import { getIdentity, putIdentity, type StoredIdentity } from "./store";

// saveAndOpen encrypts the identity under `password`, stores it on this device, and
// opens a bus session as that user. Used by join (new identity) and recover
// (re-derived identity): both end with a locally-encrypted key plus a live session.
// The mnemonic/seed is NOT touched here — only the derived keypair is persisted
// (encrypted). The private key is used to open the session IN THE BROWSER and is
// never sent to any server (unlike the old gateway model).
export async function saveAndOpen(
  identity: WalletIdentity,
  handle: string,
  password: string,
  remember = false,
): Promise<User> {
  const enc = await encryptJSON(identity, password);
  await putIdentity({
    handle,
    signPub: identity.signPub,
    kexPub: identity.kexPub,
    enc,
    createdAt: Date.now(),
  });
  return bus.openSession(identity, handle, remember);
}

// unlockAndOpen reads this device's stored identity, decrypts the private key with
// `password`, and opens a bus session locally. Throws WrongPasswordError on a bad
// password (GCM auth failure) and NoLocalIdentityError if the device has none.
export async function unlockAndOpen(password: string, remember = false): Promise<User> {
  const stored = await getIdentity();
  if (!stored) throw new NoLocalIdentityError();
  const identity = await decryptJSON<WalletIdentity>(stored.enc, password);
  return bus.openSession(identity, stored.handle, remember);
}

// localIdentity returns the device's stored identity record (or null), for the
// router to decide between the password-unlock screen and the welcome screen, and
// to greet the user by handle before unlocking.
export async function localIdentity(): Promise<StoredIdentity | null> {
  return getIdentity();
}

export class NoLocalIdentityError extends Error {
  constructor() {
    super("no local identity on this device");
    this.name = "NoLocalIdentityError";
  }
}