/**
 * The access gate's identity resolution.
 *
 * This is the piece whose failure is SILENT: get the order wrong and the broker iframe
 * reads an empty identity, provisions a second virtual user, and the returning user
 * lands in an empty space with no error anywhere. So the order is pinned, not trusted.
 */
import { test, expect, afterEach } from "bun:test";
import { configure, resetConfig, setCurrentUser, getCurrentUser } from "../src/polyfill";
import { ensureIdentity } from "../src/shared-wallet/access-gate";

const KEY = "ng-eventually:identity";

/** A localStorage double — the real one is absent in `bun test`. */
function fakeStorage(initial: Record<string, string> = {}) {
  const map = new Map(Object.entries(initial));
  return {
    getItem: (k: string) => map.get(k) ?? null,
    setItem: (k: string, v: string) => void map.set(k, v),
    removeItem: (k: string) => void map.delete(k),
    get size() { return map.size; },
  };
}

/** Put the page in a given URL + storage state, as the browser would. */
function inPage(search: string, storage: ReturnType<typeof fakeStorage>) {
  (globalThis as any).location = { search, href: "https://app.example" + search };
  (globalThis as any).localStorage = storage;
  (globalThis as any).history = { replaceState: () => {} };
}

afterEach(() => {
  setCurrentUser(null);
  resetConfig();
  delete (globalThis as any).location;
  delete (globalThis as any).localStorage;
  delete (globalThis as any).history;
});

function configured() {
  configure({
    ng: {} as never,
    useShape: (() => {}) as never,
    sharedWallet: { fileUrl: "/w.ngw", password: "pw" },
  });
}

test("an identity already set is left alone — the gate never re-asks", async () => {
  configured();
  inPage("", fakeStorage());
  setCurrentUser("alice");
  await ensureIdentity();
  expect(getCurrentUser()).toBe("alice");
});

test("the URL parameter WINS over storage — it is the only thing that crosses the frontier", async () => {
  // The top-level page and the broker iframe have separate localStorage partitions, so a
  // value written on one side is not the value the other reads. The URL survives the
  // round-trip; storage does not. If storage won here, a user entering a second
  // identifier would keep being sent back to the first one's space.
  configured();
  inPage("?ng-id=fromurl", fakeStorage({ [KEY]: "fromstorage" }));
  await ensureIdentity();
  expect(getCurrentUser()).toBe("fromurl");
});

test("the URL parameter is copied into THIS partition, so a plain reload still knows", async () => {
  configured();
  const storage = fakeStorage();
  inPage("?ng-id=carol", storage);
  await ensureIdentity();
  expect(storage.getItem(KEY)).toBe("carol");
});

test("with no parameter, storage answers — a reload does not re-ask", async () => {
  configured();
  inPage("", fakeStorage({ [KEY]: "dana" }));
  await ensureIdentity();
  expect(getCurrentUser()).toBe("dana");
});

test("nothing known and no DOM to ask on → it refuses loudly", async () => {
  // Continuing silently would provision an anonymous virtual space, which is the failure
  // this module exists to prevent. The error names what the caller must do.
  configured();
  inPage("", fakeStorage());
  await expect(ensureIdentity()).rejects.toThrow(/no DOM to ask on/i);
});

test("no shared wallet configured → it refuses, rather than inventing a space", async () => {
  configure({ ng: {} as never, useShape: (() => {}) as never });
  inPage("", fakeStorage());
  await expect(ensureIdentity()).rejects.toThrow(/no shared wallet configured/i);
});