import assert from 'node:assert/strict';
import { test } from 'node:test';
import { runInNewContext } from 'node:vm';
import type {
  GameEntry,
  GameHost,
  GameModule,
  GameServerMessage,
  PlatformGameSnapshot,
  PlatformToGameEvent,
} from '../../YouleNexus/assets/framework/sdk/contracts/index.ts';
import {
  assertGameEntry,
  GameSessionHost,
  GameSessionOpenFault,
} from '../../YouleNexus/assets/framework/sdk/runtime/game-session-host.ts';
import * as gameSessionRuntime from '../../YouleNexus/assets/framework/sdk/runtime/game-session-host.ts';

const OPEN_FAULT_BRAND_KEY = 'youle.framework.sdk.GameSessionOpenFault';

function makeHost(): GameHost {
  const snapshot: PlatformGameSnapshot = {
    connection: { phase: 'connected' },
    self: { playerId: 1, seat: 0 },
    room: { roomcode: 'fixture', roomtype: [], stage: 0, needprepare: 0, infinite: 0 },
    seats: [],
  };
  return {
    seat: { toView: (seat) => seat, toServer: (seat) => seat },
    getSnapshot: () => snapshot,
    subscribe: () => () => {},
    sendGameMessage: () => {},
    execute: () => {},
  };
}

function makeEntry(createModule: () => GameModule): GameEntry {
  return {
    key: 'fixture',
    gameId: 41,
    route: 'fixture-route',
    resolveSeatCount: () => 4,
    createModule,
  };
}

function caughtError(operation: () => void): Error {
  try {
    operation();
  } catch (error) {
    assert.ok(error instanceof Error);
    return error;
  }
  assert.fail('expected operation to throw');
}

function makeModule(log: string[], onRestore?: (deskinfo: unknown) => void): GameModule {
  let attached = false;
  return {
    attach: () => {
      attached = true;
      log.push('attach');
    },
    handlePlatformEvent: (event) => log.push(`event:${event.type}`),
    handleGameMessage: (message) => log.push(`message:${message.rpc}`),
    restore: (deskinfo) => {
      log.push('restore');
      onRestore?.(deskinfo);
    },
    dispose: () => {
      if (attached) log.push('dispose');
    },
  };
}

test('assertGameEntry rejects invalid identity, routes, seat counts, and module factories', () => {
  const entry = makeEntry(() => makeModule([]));

  assert.throws(() => assertGameEntry({ ...entry, key: '' }), /key/);
  assert.throws(() => assertGameEntry({ ...entry, gameId: '' }), /gameId/);
  for (const route of ['platform', 'agent', 'room']) {
    assert.throws(() => assertGameEntry({ ...entry, route }), /reserved.*route/);
  }
  assert.throws(() => assertGameEntry({ ...entry, resolveSeatCount: () => 0 }), /seat count/);
  assert.throws(() => assertGameEntry({ ...entry, resolveSeatCount: () => 2.5 }), /seat count/);
  assert.throws(() => assertGameEntry({ ...entry, createModule: () => undefined as never }), /module/);
});

test('assertGameEntry disposes its validation module exactly once', () => {
  let disposals = 0;
  const entry = makeEntry(() => ({
    ...makeModule([]),
    dispose: () => { disposals++; },
  }));

  assert.doesNotThrow(() => assertGameEntry(entry));

  assert.equal(disposals, 1);
});

test('GameSessionHost delivers room events and deskinfo to one active module in order', () => {
  const log: string[] = [];
  const deskinfo = { turn: 7 };
  let restoredValue: unknown;
  const sessions = new GameSessionHost(makeEntry(() => makeModule(log, (value) => { restoredValue = value; })));

  sessions.open(makeHost());
  sessions.publish({ type: 'room.entered', roomtype: ['raw', { players: 4 }] });
  sessions.restore(deskinfo);
  sessions.close();

  assert.deepEqual(log, ['attach', 'event:room.entered', 'restore', 'dispose']);
  assert.equal(restoredValue, deskinfo);
  assert.equal(sessions.state, 'idle');
});

test('GameSessionHost preserves raw platform events and game messages by identity', () => {
  let receivedEvent: PlatformToGameEvent | undefined;
  let receivedMessage: GameServerMessage | undefined;
  const sessions = new GameSessionHost(makeEntry(() => ({
    attach() {},
    handlePlatformEvent(event) { receivedEvent = event; },
    handleGameMessage(message) { receivedMessage = message; },
    restore() {},
    dispose() {},
  })));
  const rawRoomtype = ['raw', { players: 4 }];
  const rawData = { cards: [3, 7] };
  const message: GameServerMessage = { rpc: 'draw', data: rawData };
  const event: PlatformToGameEvent = { type: 'room.entered', roomtype: rawRoomtype };

  sessions.open(makeHost());
  sessions.publish(event);
  sessions.dispatchGameMessage('fixture-route', message);

  assert.equal(receivedEvent, event);
  assert.equal(receivedEvent?.roomtype, rawRoomtype);
  assert.equal(receivedMessage, message);
  assert.equal(receivedMessage?.data, rawData);
});

test('GameSessionHost rejects illegal state transitions and mismatched game routes', () => {
  const log: string[] = [];
  const sessions = new GameSessionHost(makeEntry(() => makeModule(log)));
  const message: GameServerMessage = { rpc: 'draw', data: { card: 3 } };

  assert.throws(() => sessions.publish({ type: 'room.dissolved' }), /active/);
  assert.throws(() => sessions.restore({}), /active/);
  sessions.open(makeHost());
  assert.throws(() => sessions.open(makeHost()), /open/);
  assert.throws(() => sessions.dispatchGameMessage('other-route', message), /route/);
  sessions.dispatchGameMessage('fixture-route', message);
  assert.deepEqual(log, ['attach', 'message:draw']);
});

test('GameSessionHost disposes a module when attachment throws and returns to idle', () => {
  let disposals = 0;
  const sessions = new GameSessionHost(makeEntry(() => ({
    ...makeModule([]),
    attach: () => { throw new Error('attach failed'); },
    dispose: () => { disposals++; },
  })));
  disposals = 0;

  assert.throws(() => sessions.open(makeHost()), /attach failed/);

  assert.equal(disposals, 1);
  assert.equal(sessions.state, 'idle');
});

test('GameSessionHost preserves create and contract failures when open cleanup succeeds', () => {
  const createError = new Error('create failed');
  let createCalls = 0;
  const createSessions = new GameSessionHost(makeEntry(() => {
    createCalls += 1;
    if (createCalls === 1) return makeModule([]);
    throw createError;
  }));

  assert.equal(caughtError(() => createSessions.open(makeHost())), createError);
  assert.equal(createSessions.state, 'idle');

  let contractCalls = 0;
  let contractDisposals = 0;
  const contractSessions = new GameSessionHost(makeEntry(() => {
    contractCalls += 1;
    if (contractCalls === 1) return makeModule([]);
    return {
      handlePlatformEvent() {},
      handleGameMessage() {},
      restore() {},
      dispose() { contractDisposals += 1; },
    } as unknown as GameModule;
  }));

  assert.match(caughtError(() => contractSessions.open(makeHost())).message, /implement attach/);
  assert.equal(contractDisposals, 1);
  assert.equal(contractSessions.state, 'idle');
});

test('GameSessionHost preserves attach then dispose failures by identity and occurrence order', () => {
  const attachError = new Error('attach primary');
  const disposeError = new Error('open cleanup');
  let createCalls = 0;
  let disposals = 0;
  const sessions = new GameSessionHost(makeEntry(() => {
    createCalls += 1;
    if (createCalls === 1) return makeModule([]);
    return {
      ...makeModule([]),
      attach() { throw attachError; },
      dispose() {
        disposals += 1;
        throw disposeError;
      },
    };
  }));

  const error = caughtError(() => sessions.open(makeHost()));

  assert.deepEqual(
    (error as Error & { errors?: readonly unknown[] }).errors,
    [attachError, disposeError],
  );
  assert.equal(disposals, 1);
  assert.equal(sessions.state, 'idle');
});

test('GameSessionOpenFault locks its brand and frozen error tuple against later mutation', () => {
  const primary = new Error('primary');
  const cleanup = new Error('cleanup');
  const replacement = new Error('replacement');
  const fault = new GameSessionOpenFault(primary, cleanup);
  const brand = Symbol.for(OPEN_FAULT_BRAND_KEY);
  const originalErrors = fault.errors;

  assert.deepEqual(Object.getOwnPropertyDescriptor(fault, brand), {
    value: true,
    writable: false,
    enumerable: false,
    configurable: false,
  });
  assert.deepEqual(Object.getOwnPropertyDescriptor(fault, 'errors'), {
    value: originalErrors,
    writable: false,
    enumerable: true,
    configurable: false,
  });
  assert.equal(Object.isFrozen(originalErrors), true);

  assert.throws(() => {
    (fault as unknown as { errors: unknown[] }).errors = [replacement, cleanup];
  }, TypeError);
  assert.throws(() => {
    (originalErrors as unknown as unknown[])[0] = replacement;
  }, TypeError);
  assert.throws(() => {
    Object.defineProperty(originalErrors, Symbol.iterator, {
      value: function* hostileIterator() { yield replacement; },
    });
  }, TypeError);
  assert.throws(() => {
    (fault as unknown as { [key: symbol]: unknown })[brand] = false;
  }, TypeError);

  assert.equal(fault.errors, originalErrors);
  assert.equal(fault.errors[0], primary);
  assert.equal(fault.errors[1], cleanup);
  assert.equal((fault as unknown as { [key: symbol]: unknown })[brand], true);
});

test('open fault extractor snapshots branded faults across realms without reading hostile hooks', () => {
  type OpenFaultShape = { readonly errors: readonly unknown[] };
  type OpenFaultGuard = (value: unknown) => value is OpenFaultShape;
  type OpenFaultExtractor = (value: unknown) => readonly [unknown, unknown] | null;
  const runtimeExports = gameSessionRuntime as unknown as Record<string, unknown>;
  const guardExport = runtimeExports.isGameSessionOpenFault;
  const extractorExport = runtimeExports.extractGameSessionOpenFaultErrors;
  assert.equal(typeof guardExport, 'function');
  assert.equal(typeof extractorExport, 'function');
  const isGameSessionOpenFault = guardExport as OpenFaultGuard;
  const extractGameSessionOpenFaultErrors = extractorExport as OpenFaultExtractor;
  const primary = new Error('primary');
  const cleanup = new Error('cleanup');
  const sameRealm = new GameSessionOpenFault(primary, cleanup);
  class OpenFaultSubclass extends GameSessionOpenFault {}
  const subclass = new OpenFaultSubclass(primary, cleanup);
  const foreignRealm = runInNewContext(`(() => {
    const fault = new Error('foreign open fault');
    Object.defineProperties(fault, {
      [Symbol.for(${JSON.stringify(OPEN_FAULT_BRAND_KEY)})]: { value: true },
      errors: { value: [primary, cleanup] },
    });
    return fault;
  })()`, { primary, cleanup });
  const duplicateModuleLike = new Error('duplicate module open fault');
  Object.defineProperties(duplicateModuleLike, {
    [Symbol.for(OPEN_FAULT_BRAND_KEY)]: { value: true },
    errors: { value: [primary, cleanup] },
  });
  const ordinaryAggregate = runInNewContext(
    'new AggregateError([primary, cleanup], "user aggregate")',
    { primary, cleanup },
  );
  const unbranded = { errors: [primary, cleanup] };
  let accessorReads = 0;
  const accessorSpoof = new Error('accessor spoof');
  Object.defineProperties(accessorSpoof, {
    [Symbol.for(OPEN_FAULT_BRAND_KEY)]: { value: true },
    errors: {
      get() {
        accessorReads += 1;
        throw new Error('errors getter must not run');
      },
    },
  });
  const brandAccessorSpoof = new Error('brand accessor spoof');
  Object.defineProperties(brandAccessorSpoof, {
    [Symbol.for(OPEN_FAULT_BRAND_KEY)]: {
      get() {
        accessorReads += 1;
        throw new Error('brand getter must not run');
      },
    },
    errors: { value: [primary, cleanup] },
  });
  const iteratorReplacement = new Error('iterator replacement');
  let iteratorReads = 0;
  const hostileErrors = [primary, cleanup];
  Object.defineProperty(hostileErrors, Symbol.iterator, {
    configurable: true,
    get() {
      iteratorReads += 1;
      hostileErrors[0] = iteratorReplacement;
      throw new Error('source iterator must not run');
    },
  });
  const hostileIteratorFault = new Error('hostile iterator fault');
  Object.defineProperties(hostileIteratorFault, {
    [Symbol.for(OPEN_FAULT_BRAND_KEY)]: { value: true },
    errors: { value: hostileErrors },
  });
  const descriptorTarget = new Error('descriptor failure');
  Object.defineProperties(descriptorTarget, {
    [Symbol.for(OPEN_FAULT_BRAND_KEY)]: { value: true },
    errors: { value: [primary, cleanup] },
  });
  let descriptorReads = 0;
  const descriptorFailure = new Proxy(descriptorTarget, {
    getOwnPropertyDescriptor(target, key) {
      descriptorReads += 1;
      if (key === 'errors') throw new Error('descriptor trap failed');
      return Reflect.getOwnPropertyDescriptor(target, key);
    },
  });

  assert.equal(foreignRealm instanceof GameSessionOpenFault, false);
  for (const candidate of [sameRealm, subclass, foreignRealm, duplicateModuleLike]) {
    const snapshot = extractGameSessionOpenFaultErrors(candidate);
    assert.notEqual(snapshot, null);
    assert.equal(Object.isFrozen(snapshot), true);
    assert.equal(snapshot?.[0], primary);
    assert.equal(snapshot?.[1], cleanup);
    assert.equal(isGameSessionOpenFault(candidate), true);
  }
  const hostileSnapshot = extractGameSessionOpenFaultErrors(hostileIteratorFault);
  assert.notEqual(hostileSnapshot, null);
  assert.equal(hostileSnapshot?.[0], primary);
  assert.equal(hostileSnapshot?.[1], cleanup);
  assert.equal(Object.isFrozen(hostileSnapshot), true);
  assert.equal(iteratorReads, 0);
  assert.equal(hostileErrors[0], primary);

  for (const candidate of [
    ordinaryAggregate,
    unbranded,
    accessorSpoof,
    brandAccessorSpoof,
  ]) {
    assert.equal(extractGameSessionOpenFaultErrors(candidate), null);
    assert.equal(isGameSessionOpenFault(candidate), false);
  }
  assert.equal(extractGameSessionOpenFaultErrors(descriptorFailure), null);
  assert.equal(descriptorReads, 2);
  assert.equal(accessorReads, 0);
});

test('GameSessionHost disposes a module exactly once and becomes terminal after dispose', () => {
  const log: string[] = [];
  const sessions = new GameSessionHost(makeEntry(() => makeModule(log)));

  sessions.open(makeHost());
  sessions.dispose();
  sessions.dispose();

  assert.deepEqual(log, ['attach', 'dispose']);
  assert.equal(sessions.state, 'disposed');
  assert.throws(() => sessions.open(makeHost()), /disposed/);
  assert.throws(() => sessions.publish({ type: 'room.dissolved' }), /disposed/);
});

test('GameSessionHost creates a fresh module after close', () => {
  const log: string[] = [];
  const modules: GameModule[] = [];
  const sessions = new GameSessionHost(makeEntry(() => {
    const module = makeModule(log);
    modules.push(module);
    return module;
  }));

  sessions.open(makeHost());
  sessions.close();
  sessions.open(makeHost());
  sessions.close();

  assert.notEqual(modules[modules.length - 1], modules[modules.length - 2]);
  assert.deepEqual(log, ['attach', 'dispose', 'attach', 'dispose']);
});

test('GameSessionHost returns to active after a restore handler throws', () => {
  const log: string[] = [];
  const sessions = new GameSessionHost(makeEntry(() => ({
    ...makeModule(log),
    restore: () => { throw new Error('restore failed'); },
  })));

  sessions.open(makeHost());
  assert.throws(() => sessions.restore({}), /restore failed/);
  assert.equal(sessions.state, 'active');
});