import { test } from 'node:test';
import assert from 'node:assert/strict';
import {
  WireClient,
  type WireEvent,
} from '../../YouleNexus/assets/framework/net/wire-client.ts';
import type { OutboundEnvelope } from '../../YouleNexus/assets/framework/core/types/envelope.ts';
import type { Clock } from '../../YouleNexus/assets/framework/net/heartbeat.ts';
import { FakeTransport } from '../helpers/fake-transport.ts';

function fakeClock() {
  let sequence = 0;
  let now = 0;
  const timers = new Map<number, { readonly fn: () => void; readonly at: number }>();
  const clearedTimers = new Map<number, () => void>();
  const clock: Clock = {
    setTimeout(fn, ms) {
      const id = ++sequence;
      timers.set(id, { fn, at: now + ms });
      return id;
    },
    clearTimeout(handle) {
      const id = handle as number;
      const timer = timers.get(id);
      if (timer) clearedTimers.set(id, timer.fn);
      timers.delete(id);
    },
  };
  const advance = (ms: number) => {
    now += ms;
    while (true) {
      const due = [...timers.entries()]
        .filter(([, timer]) => timer.at <= now)
        .sort(([leftId, left], [rightId, right]) => left.at - right.at || leftId - rightId)[0];
      if (!due) return;
      timers.delete(due[0]);
      due[1].fn();
    }
  };
  const fireClearedTimers = () => {
    for (const [id, fn] of [...clearedTimers]) {
      clearedTimers.delete(id);
      fn();
    }
  };
  return { clock, advance, activeTimers: () => timers.size, fireClearedTimers };
}

function makeHarness(servers: readonly string[] = ['ws://a']) {
  const transports: FakeTransport[] = [];
  const timer = fakeClock();
  const client = new WireClient({
    servers,
    clock: timer.clock,
    transportFactory: () => {
      const transport = new FakeTransport();
      transports.push(transport);
      return transport;
    },
  });
  return { client, transports, ...timer };
}

const envelope: OutboundEnvelope = {
  app: 'youle',
  route: 'agent',
  rpc: 'player_get_roomlist',
  data: { gameid: 101 },
};

test('start emits the opened server and never sends login automatically', async () => {
  const { client, transports } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));

  client.start();
  await transports[0]!.flush();

  assert.deepEqual(events, [{ type: 'open', server: 'ws://a' }]);
  assert.equal(transports[0]!.sent.length, 0, 'open 不应由 WireClient 自动发 login');
});

test('all decoded business RPCs are emitted exactly once without interception', async () => {
  const { client, transports } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const transport = transports[0]!;
  await transport.flush();

  const messages = [
    { route: 'agent', rpc: 'player_login', data: { state: 0 } },
    { route: 'agent', rpc: 'kick_server', data: { msg: 'bye' } },
    { route: 'room', rpc: 'connect_roomserver', data: { roomserver: 'ws://room' } },
    { route: 'agent', rpc: 'connect_agentserver', data: { agentserver: 'ws://agent', opt: 'free_room' } },
  ];
  for (const message of messages) transport.serverPush(JSON.stringify(message));
  await transport.flush();

  assert.deepEqual(events.slice(1), messages.map((message) => ({ type: 'message', message })));
  assert.equal(transport.sent.length, 0);
});

test('handshake, heartbeat, server-down and invalid frames are not business messages', async () => {
  const { client, transports, advance } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const transport = transports[0]!;
  await transport.flush();

  transport.serverPush('@toconconABC');
  transport.serverPush(JSON.stringify({ com: '@serverheartbeat' }));
  transport.serverPush('webserve-服务器未工作');
  transport.serverPush('not json');
  await transport.flush();

  assert.deepEqual(events, [{ type: 'open', server: 'ws://a' }]);
  assert.equal(transport.sent.length, 0);
  advance(29999);
  assert.equal(events.some((event) => event.type === 'slow'), false);
  advance(1);
  assert.equal(events.filter((event) => event.type === 'slow').length, 1);
});

test('send requires an open connection and serializes the completed envelope once', async () => {
  const { client, transports } = makeHarness();
  assert.throws(() => client.send(envelope), /connection.*open/i);

  client.start();
  const transport = transports[0]!;
  assert.throws(() => client.send(envelope), /connection.*open/i);
  await transport.flush();
  const completed = {
    data: { gameid: 101 },
    rpc: 'player_get_roomlist',
    app: 'youle',
    route: 'agent',
  } as OutboundEnvelope;
  client.send(completed);

  assert.equal(
    transport.sent[0],
    JSON.stringify(completed),
    '调用方完成的信封必须保持属性和插入顺序原样序列化',
  );
  client.stop();
  assert.throws(() => client.send(envelope), /connection.*open/i);
});

test('send rejects malformed completed envelopes before touching transport', async () => {
  const { client, transports } = makeHarness();
  client.start();
  const transport = transports[0]!;
  await transport.flush();

  const invalid: unknown[] = [
    { app: 'other', route: 'agent', rpc: 'x', data: {} },
    { app: 'youle', route: '', rpc: 'x', data: {} },
    { app: 'youle', route: 'agent', rpc: '', data: {} },
    { app: 'youle', route: 'agent', rpc: 'x' },
    null,
  ];
  for (const value of invalid) {
    assert.throws(() => client.send(value as OutboundEnvelope), /outbound envelope/i);
  }
  assert.deepEqual(transport.sent, []);
});

test('constructor rejects an empty validated server list and start cannot run twice', () => {
  assert.throws(
    () => new WireClient({ servers: [], transportFactory: () => new FakeTransport() }),
    /servers.*non-empty/i,
  );

  const { client } = makeHarness();
  client.start();
  assert.throws(() => client.start(), /already.*started/i);
});

test('switchServer validates the target before closing and reconnects to it after policy delay', async () => {
  const { client, transports, advance } = makeHarness(['ws://a', 'ws://b']);
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const first = transports[0]!;
  await first.flush();

  assert.throws(() => client.switchServer('http://room'), /WebSocket.*URL/i);
  assert.throws(() => client.switchServer('ws://'), /WebSocket.*URL/i);
  assert.equal(first.closeCalls, 0);

  client.switchServer('ws://room');
  assert.equal(first.closeCalls, 1);
  assert.deepEqual(events.slice(-2), [
    { type: 'close' },
    { type: 'reconnecting', server: 'ws://room' },
  ]);
  advance(9999);
  assert.equal(transports.length, 1);
  advance(1);
  assert.equal(transports[1]!.url, 'ws://room');
  await transports[1]!.flush();
  assert.deepEqual(events[events.length - 1], { type: 'open', server: 'ws://room' });
});

test('reconnectCurrent closes once and reconnects to the current target after 10 seconds', async () => {
  const { client, transports, advance } = makeHarness(['ws://a', 'ws://b']);
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  await transports[0]!.flush();

  client.reconnectCurrent();
  assert.equal(transports[0]!.closeCalls, 1);
  assert.deepEqual(events.slice(-2), [
    { type: 'close' },
    { type: 'reconnecting', server: 'ws://a' },
  ]);
  advance(10000);
  assert.equal(transports[1]!.url, 'ws://a');
});

test('duplicate transport close/error is handled once and failures rotate every three attempts', async () => {
  const { client, transports, advance, activeTimers } = makeHarness(['ws://a', 'ws://b']);
  const reconnectTargets: string[] = [];
  client.subscribe((event) => {
    if (event.type === 'reconnecting') reconnectTargets.push(event.server);
  });
  client.start();
  await transports[0]!.flush();

  transports[0]!.serverClose();
  await transports[0]!.flush();
  assert.deepEqual(reconnectTargets, ['ws://a']);
  advance(10000);
  await transports[1]!.flush();

  transports[1]!.serverError();
  await transports[1]!.flush();
  assert.deepEqual(reconnectTargets, ['ws://a', 'ws://a']);
  advance(10000);
  await transports[2]!.flush();

  transports[2]!.serverError();
  transports[2]!.serverClose();
  await transports[2]!.flush();
  assert.deepEqual(reconnectTargets, ['ws://a', 'ws://a', 'ws://b']);
  assert.equal(activeTimers(), 1);
  advance(10000);
  assert.equal(transports.length, 4);
  assert.equal(transports[3]!.url, 'ws://b');
});

test('a throwing close listener is reported without blocking later listeners or reconnect', async () => {
  const { client, transports, advance, activeTimers } = makeHarness();
  const listenerError = new Error('close listener failed');
  const reports: unknown[][] = [];
  let laterListenerCalls = 0;
  const originalConsoleError = console.error;
  console.error = (...args: unknown[]) => { reports.push(args); };
  try {
    client.subscribe((event) => {
      if (event.type === 'close') throw listenerError;
    });
    client.subscribe((event) => {
      if (event.type === 'close') laterListenerCalls++;
    });
    client.start();
    const first = transports[0]!;
    await first.flush();
    first.serverClose();
    await first.flush();

    assert.equal(laterListenerCalls, 1);
    assert.equal(reports.length, 1);
    assert.equal(reports[0]!.includes(listenerError), true);
    assert.equal(activeTimers(), 1);
    advance(10000);
    await transports[1]!.flush();
    assert.equal(transports[1]!.url, 'ws://a');
  } finally {
    console.error = originalConsoleError;
  }
});

test('a reconnecting listener can stop without leaving a timer or reviving a cleared callback', async () => {
  const { client, transports, advance, activeTimers, fireClearedTimers } = makeHarness();
  client.subscribe((event) => {
    if (event.type === 'reconnecting' && event.server === 'ws://room') client.stop();
  });
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverClose();
  await first.flush();
  assert.equal(activeTimers(), 1);

  client.switchServer('ws://room');

  assert.equal(activeTimers(), 0);
  fireClearedTimers();
  advance(60000);
  assert.equal(transports.length, 1);
});

test('slow listener stop prevents the timeout path from scheduling reconnect', async () => {
  const { client, transports, advance, activeTimers } = makeHarness();
  client.subscribe((event) => {
    if (event.type === 'slow') client.stop();
  });
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverPush('@toconconABC');
  await first.flush();

  advance(30000);
  await first.flush();
  assert.equal(activeTimers(), 0);
  advance(10000);
  assert.equal(transports.length, 1);
});

test('close listener stop prevents an unexpected close from scheduling reconnect', async () => {
  const { client, transports, advance, activeTimers } = makeHarness();
  client.subscribe((event) => {
    if (event.type === 'close') client.stop();
  });
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverClose();
  await first.flush();

  assert.equal(activeTimers(), 0);
  advance(10000);
  assert.equal(transports.length, 1);
});

test('switch during pending reconnect invalidates the cleared callback and connects only the explicit target', async () => {
  const { client, transports, advance, fireClearedTimers, activeTimers } = makeHarness();
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverClose();
  await first.flush();
  assert.equal(activeTimers(), 1);

  client.switchServer('ws://room');
  assert.equal(activeTimers(), 1);
  fireClearedTimers();
  assert.equal(transports.length, 1, '已清除的 ws://a timer callback 不得重新建连');
  advance(10000);

  assert.equal(transports.length, 2);
  assert.equal(transports[1]!.url, 'ws://room');
});

test('stop before pending open ignores the late open and message callbacks', async () => {
  const { client, transports } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const first = transports[0]!;
  client.stop();
  first.serverPush(JSON.stringify({ route: 'agent', rpc: 'late', data: {} }));
  await first.flush();

  assert.deepEqual(events, [{ type: 'close' }]);
  assert.deepEqual(first.sent, []);
});

test('transportFactory synchronous failure is one failure and recovers after policy delay', async () => {
  const timer = fakeClock();
  const recovered = new FakeTransport();
  const events: WireEvent[] = [];
  let factoryCalls = 0;
  const client = new WireClient({
    servers: ['ws://a', 'ws://b'],
    clock: timer.clock,
    transportFactory: () => {
      factoryCalls++;
      if (factoryCalls === 1) throw new Error('factory failed');
      return recovered;
    },
  });
  client.subscribe((event) => events.push(event));

  assert.doesNotThrow(() => client.start());
  assert.deepEqual(events, [
    { type: 'close' },
    { type: 'reconnecting', server: 'ws://a' },
  ]);
  assert.equal(timer.activeTimers(), 1);
  timer.advance(10000);
  await recovered.flush();
  assert.equal(factoryCalls, 2);
  assert.deepEqual(events[events.length - 1], { type: 'open', server: 'ws://a' });
});

test('transport connect synchronous failure ignores duplicate close/error and counts once', async () => {
  const timer = fakeClock();
  const broken = new FakeTransport();
  broken.failNextConnect(new Error('connect failed'));
  const recovered = new FakeTransport();
  const transports = [broken, recovered];
  const reconnectTargets: string[] = [];
  let closeEvents = 0;
  let factoryIndex = 0;
  const client = new WireClient({
    servers: ['ws://a', 'ws://b'],
    clock: timer.clock,
    transportFactory: () => transports[factoryIndex++]!,
  });
  client.subscribe((event) => {
    if (event.type === 'reconnecting') reconnectTargets.push(event.server);
    if (event.type === 'close') closeEvents++;
  });

  assert.doesNotThrow(() => client.start());
  broken.serverError();
  broken.serverClose();
  await broken.flush();
  assert.deepEqual(reconnectTargets, ['ws://a']);
  assert.equal(closeEvents, 1);
  assert.equal(timer.activeTimers(), 1);
  assert.equal(broken.closeCalls, 1);
  timer.advance(10000);
  await recovered.flush();
  assert.equal(recovered.url, 'ws://a');
});

test('stale transport generations cannot emit messages or opens', async () => {
  const { client, transports, advance } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverClose();
  await first.flush();

  first.serverPush(JSON.stringify({ route: 'agent', rpc: 'stale_before_reconnect', data: {} }));
  await first.flush();
  advance(10000);
  first.serverPush(JSON.stringify({ route: 'agent', rpc: 'stale_after_reconnect', data: {} }));
  await first.flush();
  await transports[1]!.flush();

  assert.deepEqual(events.filter((event) => event.type === 'message'), []);
  assert.equal(events.filter((event) => event.type === 'open').length, 2);
});

test('unsubscribe removes the listener without affecting transport lifecycle', async () => {
  const { client, transports } = makeHarness();
  const events: WireEvent[] = [];
  const unsubscribe = client.subscribe((event) => events.push(event));
  client.start();
  const transport = transports[0]!;
  await transport.flush();
  unsubscribe();
  unsubscribe();
  transport.serverPush(JSON.stringify({ route: 'agent', rpc: 'update_bean', data: { bean: 1 } }));
  await transport.flush();

  assert.deepEqual(events, [{ type: 'open', server: 'ws://a' }]);
});

test('subscribe and unsubscribe during emit use a stable listener snapshot', async () => {
  const { client, transports } = makeHarness();
  const calls: string[] = [];
  let unsubscribeSecond = (): void => undefined;
  const third = (event: WireEvent) => {
    if (event.type === 'message') calls.push(`third:${event.message.rpc}`);
  };
  client.subscribe((event) => {
    if (event.type !== 'message') return;
    calls.push(`first:${event.message.rpc}`);
    unsubscribeSecond();
    client.subscribe(third);
  });
  unsubscribeSecond = client.subscribe((event) => {
    if (event.type === 'message') calls.push(`second:${event.message.rpc}`);
  });
  client.start();
  const transport = transports[0]!;
  await transport.flush();

  transport.serverPush(JSON.stringify({ route: 'agent', rpc: 'one', data: {} }));
  await transport.flush();
  transport.serverPush(JSON.stringify({ route: 'agent', rpc: 'two', data: {} }));
  await transport.flush();

  assert.deepEqual(calls, ['first:one', 'second:one', 'first:two', 'third:two']);
});

for (const [name, frame] of [
  ['handshake', '@toconconABC'],
  ['heartbeat', JSON.stringify({ com: '@serverheartbeat' })],
] as const) {
  test(`${name} independently resets the receive watchdog sliding window`, async () => {
    const { client, transports, advance } = makeHarness();
    const events: WireEvent[] = [];
    client.subscribe((event) => events.push(event));
    client.start();
    const transport = transports[0]!;
    await transport.flush();
    transport.serverPush(frame);
    await transport.flush();
    advance(20000);
    transport.serverPush(frame);
    await transport.flush();

    advance(29999);
    assert.equal(events.some((event) => event.type === 'slow'), false);
    advance(1);
    assert.equal(events.filter((event) => event.type === 'slow').length, 1);
  });
}

test('stop is idempotent, closes an active transport once and clears its watchdog', async () => {
  const { client, transports, advance, activeTimers } = makeHarness();
  const events: WireEvent[] = [];
  client.subscribe((event) => events.push(event));
  client.start();
  const first = transports[0]!;
  await first.flush();
  first.serverPush('@toconconABC');
  await first.flush();
  assert.equal(activeTimers(), 1);

  client.stop();
  client.stop();
  assert.equal(activeTimers(), 0);
  assert.equal(first.closeCalls, 1);
  advance(60000);
  await first.flush();
  assert.equal(transports.length, 1);
  assert.equal(events.filter((event) => event.type === 'close').length, 1);
  assert.throws(() => client.send(envelope), /connection.*open/i);
});

test('stop clears a pending reconnect timer and prevents a later transport generation', async () => {
  const { client, transports, advance, activeTimers, fireClearedTimers } = makeHarness();
  client.start();
  const first = transports[0]!;
  await first.flush();

  client.reconnectCurrent();
  assert.equal(first.closeCalls, 1);
  assert.equal(activeTimers(), 1);
  client.stop();
  assert.equal(activeTimers(), 0);
  fireClearedTimers();
  advance(60000);
  await first.flush();

  assert.equal(transports.length, 1);
});