import test from 'node:test';
import assert from 'node:assert/strict';
import { readFileSync } from 'node:fs';
import vm from 'node:vm';

/*
 * Step 6.7B -- SciFi Observation Surface Integration.
 *
 * SciFi-XZBT's contract-adapter.js is self-contained (no shared
 * test-fixtures/reference-exhibits/shared/contract-core.js dependency,
 * unlike Museum Gallery) -- it is one IIFE publishing window.XZBTContractAdapter
 * directly. surface-mode.js and surface-bus.js are likewise standalone, pure
 * files with no imports, which is what makes them separately loadable and
 * testable under vm here even though js/app.js (DOM-bound, ~4900 lines) is
 * not. See docs/architecture/XZBT-NGN-Step6.7A-SciFi-Observation-Surface.md
 * SS14 for the full test plan this file implements a representative subset of.
 */

const ROOT = new URL('../test-fixtures/reference-exhibits/scifi/', import.meta.url);

function source(file) {
  return readFileSync(new URL(file, ROOT), 'utf8');
}

/** Strips vm-realm object identity so assert.deepEqual compares plain
 * host-realm structures (same technique as museum-gallery.test.js). */
function plain(value) {
  return JSON.parse(JSON.stringify(value));
}

function makeContext(extra = {}) {
  return vm.createContext({
    window: {},
    BroadcastChannel,
    URLSearchParams,
    setTimeout,
    clearTimeout,
    Math,
    Date,
    console,
    ...extra
  });
}

/** Loads surface-mode.js + contract-adapter.js only -- structurally
 * incapable of constructing app.js's audio/AI/visualizer subsystems,
 * exactly as makeSurfaceContext() does for Museum Gallery. */
function makeAdapterContext() {
  const ctx = makeContext();
  vm.runInContext(source('js/surface-mode.js'), ctx);
  vm.runInContext(source('js/contract-adapter.js'), ctx);
  return ctx;
}

function sciFiCatalog(instanceId = 'xi-test-instance') {
  const ctx = makeAdapterContext();
  const surfaces = ctx.window.XZBTSurfaceMode.SURFACES(instanceId);
  const adapter = new ctx.window.XZBTContractAdapter({
    product: 'SciFi-XZBT', version: '5.3.0', surfaces, instanceId, bindings: {}
  });
  return { ctx, adapter, surfaces: plain(surfaces), description: plain(adapter.describe()) };
}

function makeBusContext() {
  const ctx = makeContext();
  vm.runInContext(source('js/surface-bus.js'), ctx);
  return ctx;
}

function closeAll(...handles) {
  for (const h of handles) {
    try {
      if (!h) continue;
      if (typeof h.detach === 'function') h.detach();
      else if (h.owner && typeof h.owner.detach === 'function') h.owner.detach();
      else if (h.link && typeof h.link.detach === 'function') h.link.detach();
    } catch {
      /* best-effort cleanup */
    }
  }
}

function waitFor(predicate, timeoutMs = 500) {
  const deadline = Date.now() + timeoutMs;
  return new Promise((resolve, reject) => {
    (function poll() {
      if (predicate()) return resolve();
      if (Date.now() > deadline) return reject(new Error('timed out waiting for condition'));
      setTimeout(poll, 5);
    })();
  });
}

/* ------------------------------------------------------------------ *
 * 1-7: Catalog and contract conformance
 * ------------------------------------------------------------------ */

test('describe() includes a surfaces array with exactly one primary and only documented §31.2 fields', () => {
  const { description } = sciFiCatalog();
  assert.ok(Array.isArray(description.surfaces));
  assert.equal(description.surfaces.length, 2);

  const ids = description.surfaces.map((s) => s.id).sort();
  assert.deepEqual(ids, ['surface.console', 'surface.observation']);

  const primaries = description.surfaces.filter((s) => s.primary === true);
  assert.equal(primaries.length, 1, 'exactly one primary surface');
  assert.equal(primaries[0].id, 'surface.console');
  assert.equal(primaries[0].url, 'index.html');

  const ALLOWED = new Set(['id', 'label', 'kind', 'primary', 'url', 'role', 'category',
    'aspectRatio', 'requires', 'description']);
  for (const s of description.surfaces) {
    assert.equal(s.kind, 'surface');
    assert.match(s.id, /^[a-z][a-z0-9-]*(\.[a-z][a-z0-9-]*)+$/, 'canonical dotted id grammar');
    for (const key of Object.keys(s)) {
      assert.ok(ALLOWED.has(key), `unexpected field '${key}' on ${s.id}`);
    }
  }
});

test('the observation surface url is a bare query string against the same document, carrying the instance id', () => {
  const { description } = sciFiCatalog('xi-abc123');
  const observation = description.surfaces.find((s) => s.id === 'surface.observation');
  assert.equal(observation.primary, false);
  assert.equal(observation.url, '?surface=observation&xi=xi-abc123');
  assert.ok(!/^[a-zA-Z][a-zA-Z0-9+.-]*:/.test(observation.url), 'url must not carry a scheme');
  assert.ok(observation.url.indexOf('//') !== 0, 'url must not be protocol-relative');
  assert.deepEqual(observation.requires, ['observation']);
});

test('constructing the adapter with no surfaces option omits `surfaces` entirely (§31.3 form 1 preserved)', () => {
  const ctx = makeAdapterContext();
  const adapter = new ctx.window.XZBTContractAdapter({ product: 'SciFi-XZBT', version: '5.3.0', bindings: {} });
  const description = plain(adapter.describe());
  assert.equal('surfaces' in description, false);
  assert.equal(description.contract.major, 5);
  assert.equal(description.exhibit.version, '5.3.0');
});

test('view.pillars and view.warp-flight are readable/writable boolean state targets and appear in the snapshot key set', () => {
  const { ctx, adapter } = sciFiCatalog();
  const pillars = adapter.targets.get('view.pillars');
  const warp = adapter.targets.get('view.warp-flight');
  for (const target of [pillars, warp]) {
    assert.ok(target, 'target must be registered');
    assert.equal(target.kind, 'state');
    assert.equal(target.valueType, 'boolean');
    assert.equal(target.readable, true);
    assert.equal(target.writable, true);
    assert.equal(target.restorable, true);
    assert.equal(target.category, 'observation');
    assert.deepEqual(plain(target.requires), ['observation']);
  }
  const description = plain(adapter.describe());
  const ids = description.targets.map((t) => t.id);
  assert.ok(ids.includes('view.pillars'));
  assert.ok(ids.includes('view.warp-flight'));
  void ctx;
});

test('registryRevision stays 1 -- the new targets are a build-time addition, not a runtime registry change', () => {
  const { adapter } = sciFiCatalog();
  assert.equal(adapter.registryRevision, 1);
});

/* ------------------------------------------------------------------ *
 * 8-9: Mode resolution (pure, no DOM)
 * ------------------------------------------------------------------ */

test('mode resolution: no query -> console; ?surface=observation -> observation; unknown values -> console', () => {
  const ctx = makeContext();
  vm.runInContext(source('js/surface-mode.js'), ctx);
  const resolve = ctx.window.XZBTSurfaceMode.resolve;

  assert.equal(resolve({ search: '' }).mode, 'console');
  assert.equal(resolve({ search: '?foo=bar' }).mode, 'console');
  assert.equal(resolve({ search: '?surface=bogus' }).mode, 'console');
  assert.equal(resolve({ search: '?surface=observation&xi=xi-1' }).mode, 'observation');
  assert.equal(resolve({ search: '?surface=observation&xi=xi-1' }).instanceId, 'xi-1');
  // Order and extra params are tolerated.
  assert.equal(resolve({ search: '?xi=xi-2&extra=1&surface=observation' }).mode, 'observation');
  assert.equal(resolve({ search: '?xi=xi-2&extra=1&surface=observation' }).instanceId, 'xi-2');
});

test('channelName is instance-scoped: two instance ids yield two different channel names', () => {
  const ctx = makeContext();
  vm.runInContext(source('js/surface-mode.js'), ctx);
  const { channelName, newInstanceId } = ctx.window.XZBTSurfaceMode;
  const a = newInstanceId();
  const b = newInstanceId();
  assert.notEqual(a, b);
  assert.notEqual(channelName(a), channelName(b));
  assert.ok(channelName(a).startsWith('xzbt-scifi-surface-v1:'));
});

/* ------------------------------------------------------------------ *
 * 10-17: Bus / synchronization (surface-bus.js against a minimal stub
 * adapter -- exercises the bus mechanism itself, independent of app.js)
 * ------------------------------------------------------------------ */

/** A minimal stand-in for XZBTContractAdapter: just enough surface for
 * surface-bus.js's owner side (getContractState/applyMutation/invokeAction/
 * targets/stateRevision/registryRevision), with the same session-independent
 * onLocalChange/onLocalAction contract the real adapter now provides. */
function makeStubAdapter() {
  const targets = new Map([
    ['view.pillars', { id: 'view.pillars', kind: 'state', readable: true, writable: true }],
    ['preset.selected', { id: 'preset.selected', kind: 'selection', readable: true, writable: true }]
  ]);
  const state = { 'view.pillars': false, 'preset.selected': 'a' };
  const adapter = {
    targets,
    stateRevision: 0,
    registryRevision: 1,
    onLocalChange: null,
    onLocalAction: null,
    getContractState: () => ({ ...state }),
    applyMutation: (id, value) => {
      if (!targets.has(id)) return { ok: false };
      state[id] = value;
      adapter.stateRevision += 1;
      if (adapter.onLocalChange) adapter.onLocalChange(id, value, adapter.stateRevision);
      return { ok: true };
    },
    invokeAction: (id, args) => {
      if (adapter.onLocalAction) adapter.onLocalAction(id, args || {});
      return { ok: true };
    }
  };
  return adapter;
}

function makeOwner(channelName) {
  const ctx = makeBusContext();
  const adapter = makeStubAdapter();
  const owner = ctx.window.XZBTSurfaceBus.createOwner(adapter, { channelName });
  adapter.onLocalChange = (id, value, rev) => owner.broadcastState(id, value, rev);
  adapter.onLocalAction = (id, args) => owner.broadcastAction(id, args);
  return { ctx, adapter, owner };
}

function attachSurface(channelName, timeoutMs) {
  const ctx = makeBusContext();
  const changes = [];
  const actions = [];
  const presentations = [];
  return new Promise((resolve, reject) => {
    const link = ctx.window.XZBTSurfaceBus.attach({
      channelName,
      timeoutMs: timeoutMs || 500,
      onSnapshot: (values, stateRevision, registryRevision, presentation) =>
        resolve({ ctx, link, changes, actions, presentations, values: plain(values), stateRevision, registryRevision, presentation: plain(presentation) }),
      onChange: (target, value, stateRevision) => changes.push({ target, value, stateRevision }),
      onAction: (target, args) => actions.push({ target, args: plain(args) }),
      onPresentation: (kind, payload) => presentations.push({ kind, payload: plain(payload) }),
      onTimeout: () => reject(new Error('attach timed out waiting for an owner'))
    });
  });
}

test('late join: attach after a mutation carries the current value and stateRevision in the snapshot', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-latejoin-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let surface;
  try {
    adapter.applyMutation('view.pillars', true);
    surface = await attachSurface(channel);
    assert.equal(surface.values['view.pillars'], true);
    assert.equal(surface.stateRevision, adapter.stateRevision);
  } finally {
    closeAll(owner, surface);
  }
});

test('propagation: an authority mutation reaches an attached surface as one state message with the post-mutation value', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-propagate-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let surface;
  try {
    surface = await attachSurface(channel);
    adapter.applyMutation('preset.selected', 'b');
    await waitFor(() => surface.changes.some((c) => c.target === 'preset.selected' && c.value === 'b'));
    const matches = surface.changes.filter((c) => c.target === 'preset.selected');
    assert.equal(matches.length, 1);
    assert.equal(matches[0].stateRevision, adapter.stateRevision);
  } finally {
    closeAll(owner, surface);
  }
});

test('mutation routing: a surface-side mutate results in exactly one applyMutation call and converges on a second attached surface', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-routing-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let applyCount = 0;
  const origApply = adapter.applyMutation;
  adapter.applyMutation = (...args) => { applyCount += 1; return origApply(...args); };
  let surfaceA, surfaceB;
  try {
    surfaceA = await attachSurface(channel);
    surfaceB = await attachSurface(channel);
    surfaceA.link.mutate('set', 'view.pillars', true);
    await waitFor(() => surfaceB.changes.some((c) => c.target === 'view.pillars' && c.value === true));
    assert.equal(applyCount, 1);
    assert.equal(adapter.getContractState()['view.pillars'], true, 'authority converged');
    assert.ok(surfaceA.changes.some((c) => c.target === 'view.pillars' && c.value === true), 'originating surface also converges (no local write)');
  } finally {
    closeAll(owner, surfaceA, surfaceB);
  }
});

test('no second authority: a surface-side mutate with no owner present is a no-op and the surface stays in the waiting state', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-noowner-' + Math.random();
  const ctx = makeBusContext();
  let timedOut = false;
  const link = await new Promise((resolve) => {
    const l = ctx.window.XZBTSurfaceBus.attach({
      channelName: channel,
      timeoutMs: 60,
      onSnapshot: () => resolve(l),
      onTimeout: () => { timedOut = true; resolve(l); }
    });
  });
  try {
    assert.equal(timedOut, true);
    assert.equal(link.isAttached(), false);
    assert.equal(link.mutate('set', 'view.pillars', true), false, 'mutate before/without attachment is a no-op');
  } finally {
    closeAll(link);
  }
});

test('reload: re-attaching with a fresh participantId yields the current snapshot and does not ratchet the participant count', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-reload-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let first, second;
  try {
    first = await attachSurface(channel);
    assert.equal(owner.attachedCount(), 1);
    first.link.detach();
    await waitFor(() => owner.attachedCount() === 0);
    adapter.applyMutation('view.pillars', true);
    second = await attachSurface(channel);
    assert.equal(owner.attachedCount(), 1, 'reload does not ratchet the count');
    assert.equal(second.values['view.pillars'], true, 'reattach observes current state');
  } finally {
    closeAll(owner, first, second);
  }
});

test('detach is idempotent, never mutates state, and cannot underflow the participant count', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-detach-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let surface;
  try {
    surface = await attachSurface(channel);
    const revBefore = adapter.stateRevision;
    surface.link.detach();
    surface.link.detach(); // duplicate detach must not underflow
    await waitFor(() => owner.attachedCount() === 0);
    assert.equal(owner.attachedCount(), 0);
    assert.equal(adapter.stateRevision, revBefore, 'detaching must not itself mutate state');
  } finally {
    closeAll(owner, surface);
  }
});

test('session independence: onLocalChange fires regardless of any session concept -- the bus has no idea NGN exists', async () => {
  // The stub adapter here has no sessionActive/eventSequence at all, which is
  // the point: onLocalChange is a plain method call, not gated on a session,
  // unlike the real adapter's _emitEvent (contract-adapter.js §5.4).
  const channel = 'xzbt-scifi-surface-v1:test-sessionindep-' + Math.random();
  const { adapter, owner } = makeOwner(channel);
  let surface;
  try {
    surface = await attachSurface(channel);
    adapter.applyMutation('view.pillars', true);
    await waitFor(() => surface.changes.length > 0);
    assert.equal(surface.changes[0].target, 'view.pillars');
  } finally {
    closeAll(owner, surface);
  }
});

test('presentation messages (ticker, obs-activity) are relayed to attached surfaces and are not contract state', async () => {
  const channel = 'xzbt-scifi-surface-v1:test-presentation-' + Math.random();
  const { owner } = makeOwner(channel);
  let surface;
  try {
    surface = await attachSurface(channel);
    owner.broadcastPresentation('ticker', { tickerText: 'HELLO WORLD' });
    owner.broadcastPresentation('obs-activity', { source: 'ambient' });
    await waitFor(() => surface.presentations.length >= 2);
    assert.deepEqual(surface.presentations[0], { kind: 'ticker', payload: { type: 'presentation', kind: 'ticker', tickerText: 'HELLO WORLD' } });
    assert.equal(surface.presentations[1].kind, 'obs-activity');
  } finally {
    closeAll(owner, surface);
  }
});

/* ------------------------------------------------------------------ *
 * 18: Duplicate-subsystem prevention -- construction spy on surface-bus.js
 * ------------------------------------------------------------------ */

test('surface-bus.js never touches AudioContext, fetch or dynamic import, in either owner or surface role', async () => {
  let audioContextConstructions = 0;
  const ctx = vm.createContext({
    window: {},
    BroadcastChannel,
    setTimeout, clearTimeout, Math, Date, console,
    AudioContext: class { constructor() { audioContextConstructions += 1; } },
    fetch: () => { throw new Error('surface-bus.js must never fetch'); }
  });
  vm.runInContext(source('js/surface-bus.js'), ctx);
  const channel = 'xzbt-scifi-surface-v1:test-spy-' + Math.random();
  const adapter = makeStubAdapter();
  const owner = ctx.window.XZBTSurfaceBus.createOwner(adapter, { channelName: channel });
  adapter.onLocalChange = (id, value, rev) => owner.broadcastState(id, value, rev);
  let link;
  try {
    link = await new Promise((resolve, reject) => {
      const l = ctx.window.XZBTSurfaceBus.attach({
        channelName: channel, timeoutMs: 500,
        onSnapshot: () => resolve(l),
        onTimeout: () => reject(new Error('attach timed out'))
      });
    });
    link.mutate('set', 'view.pillars', true);
    await waitFor(() => adapter.getContractState()['view.pillars'] === true);
    assert.equal(audioContextConstructions, 0);
  } finally {
    closeAll(owner, link);
  }
});

/* ------------------------------------------------------------------ *
 * 19-21: app.js is too DOM-bound for vm (per the architecture doc's own
 * assessment) -- these are asserted as source-structure tests, the same
 * technique museum-gallery.test.js uses for "exactly one Exhibit State
 * Core exists".
 * ------------------------------------------------------------------ */

function appJsSource() {
  return source('js/app.js');
}

test('source structure: enterObservation() only calls prepareExperience() inside an isConsoleMode guard', () => {
  const src = appJsSource();
  const fnStart = src.indexOf('function enterObservation()');
  assert.ok(fnStart >= 0, 'enterObservation() must exist');
  const fnEnd = src.indexOf('\n  function exitObservation()', fnStart);
  assert.ok(fnEnd > fnStart);
  const body = src.slice(fnStart, fnEnd);
  // Search for the real call site, not the word appearing in a comment.
  const callIdx = body.indexOf('generativeExperience.prepareExperience()');
  assert.ok(callIdx >= 0, 'enterObservation() must still prepare the generative experience somewhere');
  const guardIdx = body.lastIndexOf('if (isConsoleMode) {', callIdx);
  assert.ok(guardIdx >= 0 && guardIdx < callIdx, 'prepareExperience() must be reached only through an isConsoleMode guard');
  // The guard's closing brace must come after the call (i.e. the call is
  // actually nested inside the guard, not merely preceded by one elsewhere).
  const closeIdx = body.indexOf('\n    }', callIdx);
  assert.ok(closeIdx > callIdx, 'the isConsoleMode guard must close after the prepareExperience() call');
});

test('source structure: XZBTGenerativeExperience, XZBTContractAdapter, XZBTControlBus and StarshipVisualizer construction sites are each reached only through an isConsoleMode check', () => {
  const src = appJsSource();
  for (const ctor of ['new XZBTGenerativeExperience(', 'new XZBTControlBus(', 'new XZBTContractAdapter(', 'new StarshipVisualizer(']) {
    const idx = src.indexOf(ctor);
    assert.ok(idx >= 0, `${ctor} construction site must exist`);
    // The isConsoleMode identifier (either as an if-guard or a ternary
    // condition) must appear on a line at or before the construction site,
    // within a reasonably tight window -- resilient to exact formatting,
    // unlike a brittle single-line regex.
    const window_ = src.slice(Math.max(0, idx - 400), idx);
    assert.ok(window_.includes('isConsoleMode'), `${ctor} must be structurally gated on isConsoleMode`);
  }
});

test('source structure: the keydown hotkey listener is installed only inside an isConsoleMode guard', () => {
  const src = appJsSource();
  const idx = src.indexOf("window.addEventListener('keydown'");
  assert.ok(idx >= 0);
  const before = src.slice(Math.max(0, idx - 200), idx);
  assert.ok(before.includes('if (isConsoleMode)'), 'keydown listener must be console-mode only');
});

test('source structure: scheduleObservationAmbientActivity() refuses to run at all outside console mode (no independent surface-side timer)', () => {
  const src = appJsSource();
  const fnStart = src.indexOf('function scheduleObservationAmbientActivity()');
  assert.ok(fnStart >= 0);
  const fnBody = src.slice(fnStart, fnStart + 600);
  assert.match(fnBody, /if\s*\(!isConsoleMode\)\s*return;/, 'the scheduler must early-return outside console mode');
});

test('source structure: the observation-audience predicate considers attached surfaces, not just the local overlay flag', () => {
  const src = appJsSource();
  assert.match(src, /observationAudienceActive\s*=\s*\(\)\s*=>\s*observationActive\s*\|\|/, 'audience-active must OR in attached-surface state');
  assert.match(src, /surfaceOwner\s*&&\s*surfaceOwner\.attachedCount\(\)\s*>\s*0/, 'must consult surfaceOwner.attachedCount()');
});

test('source structure: opening the surface never sets view.observation (surface lifecycle and the console overlay flag stay distinct)', () => {
  const src = appJsSource();
  // The presentation attach path's onSnapshot handler must call
  // enterObservation() (unconditional local render) and must never call
  // applyMutation('view.observation', ...) or mutate('set', 'view.observation', ...).
  const snapshotIdx = src.indexOf('onSnapshot: (values, stateRevision, registryRevision, presentation)');
  assert.ok(snapshotIdx >= 0);
  const handlerEnd = src.indexOf('onChange:', snapshotIdx);
  const handlerBody = src.slice(snapshotIdx, handlerEnd);
  assert.ok(handlerBody.includes('enterObservation()'));
  assert.ok(!handlerBody.includes("'view.observation'"), 'the snapshot handler must never touch view.observation');
});

test('source structure: presentation-side dock routing excludes view.observation from the routed target set', () => {
  const src = appJsSource();
  const idx = src.indexOf('XZBT_PRESENTATION_ROUTED_TARGETS');
  assert.ok(idx >= 0);
  const block = src.slice(idx, idx + 300);
  assert.ok(!block.includes("'view.observation'"), 'view.observation must never be routed from the surface to the owner');
  for (const target of ['view.warp-flight', 'view.viewport-frame', 'view.pillars', 'alert.active', 'preset.selected']) {
    assert.ok(block.includes(`'${target}'`), `${target} must be routed`);
  }
});

test('source structure: contract-adapter.js exposes onLocalChange/onLocalAction independent of the sessionActive gate on _emitEvent', () => {
  const src = source('js/contract-adapter.js');
  assert.match(src, /if\s*\(!this\.sessionActive\)\s*return;/, '_emitEvent\'s session gate must remain');
  assert.match(src, /this\.onLocalChange\s*\(/, 'onLocalChange must be invoked');
  assert.match(src, /this\.onLocalAction\s*\(/, 'onLocalAction must be invoked');
  // The onLocalChange call site must not itself be behind a sessionActive check.
  const idx = src.indexOf('if (this.onLocalChange) {');
  assert.ok(idx >= 0);
  const nearby = src.slice(Math.max(0, idx - 150), idx);
  assert.ok(!nearby.includes('sessionActive'), 'onLocalChange must fire regardless of sessionActive');
});