import { SimplePool, finalizeEvent, generateSecretKey, getPublicKey } from 'https://esm.sh/nostr-tools@2.7.2';

// Addressable (NIP-01 30000-39999 range) kind for "current room status".
// Not a registered NIP kind -- picked clear of known reserved numbers
// (long-form 30023, live event 30311, classified listing 30402/3,
// calendar 31922/3, app handler 31989/90, git repo 30617/8). Addressable
// events are scoped per (pubkey, kind, d-tag), so this only collides with
// another app if it ALSO renders unrelated JSON under the same kind in a
// confusing way -- worth registering properly if this grows beyond a demo.
const ROOM_STATUS_KIND = 33001;
const LOG_KIND = 1;

const STORAGE_KEYS = {
  relays: 'checkstr.relays',
  propertyId: 'checkstr.propertyId',
  demoSecretKey: 'checkstr.demoSecretKey',
};

// Picked after actually testing publish-ACK behavior for a brand-new
// pubkey, not on reputation: wss://relay.damus.io was returning 503 at the
// WS handshake, and wss://nos.lol accepted the connection but never sent
// an OK for a first-time key's event (no error either -- just silence).
// These three gave an explicit OK within a couple seconds in that same
// test. Relay behavior drifts over time; re-verify if check-in starts
// hanging again rather than assuming these stay good forever.
const DEFAULT_RELAYS = [
  'wss://relay.primal.net',
  'wss://offchain.pub',
  'wss://relay.nostr.wirednet.jp',
];

const PUBLISH_TIMEOUT_MS = 10_000;

function withTimeout(promise, ms, message) {
  let timer;
  const timeout = new Promise((_, reject) => {
    timer = setTimeout(() => reject(new Error(message)), ms);
  });
  return Promise.race([promise, timeout]).finally(() => clearTimeout(timer));
}

const pool = new SimplePool();

const state = {
  pubkey: null,
  signMode: null, // 'nip07' | 'demo'
  demoSk: null,
  relays: loadRelays(),
  propertyId: localStorage.getItem(STORAGE_KEYS.propertyId) || '',
  rooms: new Map(), // roomId -> { status, guest, since, eventCreatedAt }
  log: [], // recent activity notes, newest first
  roomSub: null,
  logSub: null,
};

function loadRelays() {
  const raw = localStorage.getItem(STORAGE_KEYS.relays);
  if (!raw) return DEFAULT_RELAYS;
  try {
    const parsed = JSON.parse(raw);
    return Array.isArray(parsed) && parsed.length ? parsed : DEFAULT_RELAYS;
  } catch {
    return DEFAULT_RELAYS;
  }
}

function saveRelays(relays) {
  state.relays = relays;
  localStorage.setItem(STORAGE_KEYS.relays, JSON.stringify(relays));
}

function savePropertyId(id) {
  state.propertyId = id;
  localStorage.setItem(STORAGE_KEYS.propertyId, id);
}

function roomTag() {
  return `checkstr-${state.propertyId}`;
}

// --- Auth ---

async function loginWithExtension() {
  if (!window.nostr) throw new Error('No NIP-07 extension found (e.g. Alby, nos2x).');
  const pubkey = await window.nostr.getPublicKey();
  state.pubkey = pubkey;
  state.signMode = 'nip07';
  return pubkey;
}

function loginWithDemoKey() {
  let hex = localStorage.getItem(STORAGE_KEYS.demoSecretKey);
  let sk;
  if (hex) {
    sk = Uint8Array.from(hex.match(/.{2}/g).map((b) => parseInt(b, 16)));
  } else {
    sk = generateSecretKey();
    localStorage.setItem(
      STORAGE_KEYS.demoSecretKey,
      Array.from(sk).map((b) => b.toString(16).padStart(2, '0')).join(''),
    );
  }
  state.demoSk = sk;
  state.pubkey = getPublicKey(sk);
  state.signMode = 'demo';
  return state.pubkey;
}

async function signEvent(template) {
  if (state.signMode === 'nip07') return window.nostr.signEvent(template);
  if (state.signMode === 'demo') return finalizeEvent(template, state.demoSk);
  throw new Error('Not logged in');
}

// --- Publishing ---

// Publishes a signed event and waits for at least one relay to ACK it.
// Normalizes BOTH failure paths to one clear message: either every relay
// rejects (AggregateError, whose default message is useless) or none
// respond at all within PUBLISH_TIMEOUT_MS (the actual bug this fixes --
// a relay that accepts the connection but silently never sends OK used to
// hang the UI forever with zero feedback).
async function publishAndWait(signed, what) {
  try {
    await withTimeout(
      Promise.any(pool.publish(state.relays, signed)),
      PUBLISH_TIMEOUT_MS,
      `No relay acknowledged the ${what} within ${PUBLISH_TIMEOUT_MS / 1000}s. Try different relays in Setup.`,
    );
  } catch (err) {
    if (err instanceof AggregateError) {
      throw new Error(`All ${state.relays.length} relay(s) rejected the ${what}.`);
    }
    throw err;
  }
}

async function publishRoomStatus(roomId, { status, guest, since }) {
  const template = {
    kind: ROOM_STATUS_KIND,
    created_at: Math.floor(Date.now() / 1000),
    tags: [
      ['d', `${state.propertyId}:${roomId}`],
      ['status', status],
      ['room', roomId],
      ['t', roomTag()],
    ],
    content: JSON.stringify({ guest: guest || null, since: since || null }),
  };
  const signed = await signEvent(template);
  await publishAndWait(signed, 'room-status update');
  return signed;
}

async function publishLog(text, roomId) {
  const template = {
    kind: LOG_KIND,
    created_at: Math.floor(Date.now() / 1000),
    tags: [
      ['t', 'checkstr'],
      ['t', roomTag()],
      ['room', roomId],
    ],
    content: text,
  };
  const signed = await signEvent(template);
  await publishAndWait(signed, 'activity log entry');
  return signed;
}

export async function checkIn(roomId, guestName) {
  const since = Math.floor(Date.now() / 1000);
  await publishRoomStatus(roomId, { status: 'occupied', guest: guestName, since });
  await publishLog(`Checked in: ${guestName} → room ${roomId}`, roomId);
}

export async function checkOut(roomId) {
  const room = state.rooms.get(roomId);
  const guestName = room?.guest || 'guest';
  await publishRoomStatus(roomId, { status: 'vacant', guest: null, since: null });
  await publishLog(`Checked out: ${guestName} ← room ${roomId}`, roomId);
}

// --- Subscriptions ---

function applyRoomEvent(evt) {
  const dTag = evt.tags.find((t) => t[0] === 'd')?.[1];
  if (!dTag) return;
  const roomId = dTag.split(':').slice(1).join(':');
  const existing = state.rooms.get(roomId);
  // Addressable events: only the newest created_at for this d-tag matters.
  if (existing && existing.eventCreatedAt >= evt.created_at) return;
  let parsed = {};
  try {
    parsed = JSON.parse(evt.content);
  } catch {
    // malformed content from a non-conforming publisher; keep status tag only
  }
  const status = evt.tags.find((t) => t[0] === 'status')?.[1] || 'unknown';
  state.rooms.set(roomId, {
    status,
    guest: parsed.guest ?? null,
    since: parsed.since ?? null,
    eventCreatedAt: evt.created_at,
  });
  window.dispatchEvent(new CustomEvent('checkstr:rooms-changed'));
}

function applyLogEvent(evt) {
  if (state.log.some((e) => e.id === evt.id)) return;
  state.log.unshift(evt);
  state.log = state.log.slice(0, 50);
  window.dispatchEvent(new CustomEvent('checkstr:log-changed'));
}

export function subscribe() {
  unsubscribe();
  if (!state.pubkey || !state.propertyId) return;
  state.roomSub = pool.subscribeMany(
    state.relays,
    [{ kinds: [ROOM_STATUS_KIND], authors: [state.pubkey], '#t': [roomTag()] }],
    { onevent: applyRoomEvent },
  );
  state.logSub = pool.subscribeMany(
    state.relays,
    [{ kinds: [LOG_KIND], '#t': [roomTag()], limit: 50 }],
    { onevent: applyLogEvent },
  );
}

export function unsubscribe() {
  state.roomSub?.close();
  state.logSub?.close();
  state.roomSub = null;
  state.logSub = null;
  state.rooms.clear();
  state.log = [];
}

export { state, loginWithExtension, loginWithDemoKey, saveRelays, savePropertyId };