import { expect, test } from "bun:test";
import { createStore, DEFAULT_STATE, parseState, stateToSearch } from "../src/app/state";

test("a full state round-trips through the URL", () => {
  const s = parseState("?song=survive&tab=listen&motif=polyphemus&timeline=closed&ribbons=1&read=1");
  expect(s).toEqual({ songId: "survive", tab: "listen", motif: "polyphemus", timeline: "closed", ribbons: true, read: true });
  expect(parseState(stateToSearch(s))).toEqual(s);
});

test("unknown song, tab and motif fall back to the defaults", () => {
  expect(parseState("?song=nope&tab=x&motif=nobody&timeline=sideways")).toEqual(DEFAULT_STATE);
  expect(DEFAULT_STATE.songId).toBe("the-horse-and-the-infant");
});

test("the default state has an empty query", () => {
  expect(stateToSearch(DEFAULT_STATE)).toBe("");
});

test("the store notifies subscribers with the new and previous state", () => {
  const store = createStore(DEFAULT_STATE, { history: false });
  const seen: [string, string][] = [];
  const off = store.subscribe((s, prev) => seen.push([prev.songId, s.songId]));
  store.set({ songId: "polyphemus" });
  off();
  store.set({ songId: "storm" });
  expect(seen).toEqual([["the-horse-and-the-infant", "polyphemus"]]);
  expect(store.get().songId).toBe("storm");
});