import { createStore } from "./store";

// The debug recorder's app-wide state (E16) — what several surfaces open or read, held outside any
// one of them: Settings, the command palette and the recorder itself all open the start dialog, and
// the composer opens for whichever session just ended.

const startOpen = createStore(false);
/** Open the start dialog (Settings → Diagnosztika, the palette). */
export const openRecorderStart = (): void => startOpen.set(true);
export const closeRecorderStart = (): void => startOpen.set(false);
export const useRecorderStartOpen = (): boolean => startOpen.use();

// The pill's step prompt — open, and what is typed in it — held here, not in the pill: the pill
// rides the topmost toast host, and a dialog or the player opening or closing moves it to another
// one (a remount). The prompt must come along with what was typed.
const stepPrompt = createStore<string | null>(null);
/** The step prompt's text while it is open, else null. */
export const useStepPrompt = (): string | null => stepPrompt.use();
export const setStepPrompt = (text: string | null): void => stepPrompt.set(text);

// Other tabs of this browser: a Start or a Stop in one is news to the rest, which otherwise learn of
// it only at their next `me` poll — and meanwhile record into a session that has ended.
const CHANNEL = "siftlode.debugSession";
let channel: BroadcastChannel | null | undefined;
function tabs(): BroadcastChannel | null {
  if (channel === undefined)
    channel = typeof BroadcastChannel === "undefined" ? null : new BroadcastChannel(CHANNEL);
  return channel;
}
/** Tell the other tabs the recording started or stopped. */
export const announceSessionChange = (): void => tabs()?.postMessage("changed");
/** Run `fn` when another tab started or stopped a recording. */
export function onSessionChangeElsewhere(fn: () => void): () => void {
  const c = tabs();
  if (!c) return () => {};
  const handler = () => fn();
  c.addEventListener("message", handler);
  return () => c.removeEventListener("message", handler);
}

const composing = createStore<string | null>(null);
/** Open the issue composer for session `id` — after Stop, when the cap ends it, from Settings. */
export const openComposer = (id: string): void => composing.set(id);
export const closeComposer = (): void => composing.set(null);
export const useComposerSession = (): string | null => composing.use();

// Step markers are numbered per session. The count survives a reload (sessionStorage, per tab): a
// reproduction is often "reload and it happens again", and step 4 coming back as step 1 would make
// the list the issue is drafted from contradict itself.
const STEP_KEY = "siftlode.debugSteps";

function readSteps(): Record<string, number> {
  try {
    const raw = JSON.parse(sessionStorage.getItem(STEP_KEY) ?? "{}") as unknown;
    return raw && typeof raw === "object" ? (raw as Record<string, number>) : {};
  } catch {
    return {};
  }
}

const steps = createStore<Record<string, number>>(readSteps());

/** How many steps session `id` has marked in this tab. */
export const useStepCount = (id: string): number => steps.use()[id] ?? 0;

/** Take the next step number for session `id`. */
export function nextStep(id: string): number {
  const n = (steps.get()[id] ?? 0) + 1;
  // Only this session's count is kept: the others ended, and their numbers are in their events.
  steps.set({ [id]: n });
  try {
    sessionStorage.setItem(STEP_KEY, JSON.stringify(steps.get()));
  } catch {
    // Storage off: the count lives until the reload, which is all it is for.
  }
  return n;
}