'use strict';

const test = require('node:test');
const assert = require('node:assert');

const { PhysicsRecorder, DEFAULT_MAX_TICKS } = require('../src/core/physicsRecorder');
const { FakeBot } = require('./helpers/fakeBot');

/** 造一个站在石头上的假 bot（脚下是 stone，便于断言方块名） */
function setup(options) {
  const opts = options || {};
  const bot = new FakeBot({ x: 0, y: 64, z: 0 });
  bot.blockMap.set('0,63,0', { name: 'stone', boundingBox: 'block' });
  bot.blockMap.set('0,64,0', { name: 'air', boundingBox: 'empty' });
  bot.blockMap.set('0,65,0', { name: 'air', boundingBox: 'empty' });
  const recorder = new PhysicsRecorder(opts);
  recorder.setBot(bot);
  return { bot, recorder };
}

/** 模拟一 tick：先改位置/速度/碰撞状态，再触发 physicsTick */
function tick(bot, patch) {
  Object.assign(bot.entity, patch || {});
  bot.emit('physicsTick');
}

test('没有 bot 时拒绝开始录制', () => {
  const recorder = new PhysicsRecorder();
  const result = recorder.start(1);
  assert.strictEqual(result.ok, false);
  assert.match(result.message, /没有可录制的连接/);
  assert.strictEqual(recorder.running, false);
});

test('逐 tick 记录输入、速度、位移与脚下方块', () => {
  const { bot, recorder } = setup();
  assert.strictEqual(recorder.start(1).ok, true);
  assert.strictEqual(recorder.running, true);

  bot.setControlState('forward', true);
  bot.entity.velocity.set(0.1, -0.078, 0);
  tick(bot, { position: bot.entity.position.offset(0, 0, 0.1) });
  tick(bot, { position: bot.entity.position.offset(0, 0, 0.1) });

  const snap = recorder.snapshot();
  assert.strictEqual(snap.count, 2);
  assert.strictEqual(snap.physicsEnabled, true);
  const first = snap.ticks[0];
  assert.strictEqual(first.control.forward, true);
  assert.strictEqual(first.control.back, false);
  assert.strictEqual(first.vx, 0.1);
  assert.strictEqual(first.onGround, true);
  assert.strictEqual(first.blockBelow, 'stone');
  assert.strictEqual(first.blockAtFeet, 'air');
  assert.strictEqual(first.blockAtHead, 'air');
  // 录制开始时会先取一次当前位置当基线，所以第一个 tick 也有有效位移
  assert.strictEqual(first.dz, 0.1);
  assert.strictEqual(snap.ticks[1].dz, 0.1);
  assert.strictEqual(snap.inputTicks, 2);
  assert.strictEqual(snap.inputMovedTicks, 2);
  assert.strictEqual(snap.maxHorizDelta, 0.1);
});

test('有输入但没位移且物理报告水平碰撞 → 记为「被方块挡住」', () => {
  const { bot, recorder } = setup();
  recorder.start();
  bot.setControlState('forward', true);
  // 位置不变、物理报告水平碰撞：典型的「撞墙」
  tick(bot, { isCollidedHorizontally: true });
  tick(bot, { isCollidedHorizontally: true });

  const snap = recorder.snapshot();
  assert.strictEqual(snap.inputTicks, 2);
  assert.strictEqual(snap.inputMovedTicks, 0);
  assert.strictEqual(snap.blockedTicks, 2);
  assert.strictEqual(snap.frozenTicks, 0, '报告了碰撞就不算「输入没生效」');
});

test('有输入但没位移且物理没报告碰撞 → 记为「输入没进物理」', () => {
  const { bot, recorder } = setup();
  recorder.start();
  bot.setControlState('forward', true);
  // 位置不变、速度恒为 0、也没有碰撞报告：输入根本没生效
  tick(bot, { isCollidedHorizontally: false });
  tick(bot, { isCollidedHorizontally: false });

  const snap = recorder.snapshot();
  assert.strictEqual(snap.inputTicks, 2);
  assert.strictEqual(snap.inputMovedTicks, 0);
  assert.strictEqual(snap.frozenTicks, 2);
  assert.strictEqual(snap.blockedTicks, 0, '没报告碰撞就不算「被挡住」');
});

test('没有输入时不计入 inputTicks', () => {
  const { bot, recorder } = setup();
  recorder.start();
  tick(bot);
  tick(bot);
  const snap = recorder.snapshot();
  assert.strictEqual(snap.count, 2);
  assert.strictEqual(snap.inputTicks, 0);
  assert.strictEqual(snap.movedTicks, 0);
});

test('停止后摘掉监听并不再记录', () => {
  const { bot, recorder } = setup();
  recorder.start();
  tick(bot);
  const result = recorder.stop();
  assert.strictEqual(result.ok, true);
  assert.strictEqual(recorder.running, false);
  assert.match(result.message, /共 1 个 tick/);

  tick(bot);
  assert.strictEqual(recorder.snapshot().count, 1, '停止后不应再记录');
  assert.strictEqual(bot.listenerCount('physicsTick'), 0, '监听应已摘掉');
});

test('重复 stop 不报错', () => {
  const { recorder } = setup();
  recorder.start();
  assert.strictEqual(recorder.stop().ok, true);
  assert.match(recorder.stop().message, /没有在录制/);
});

test('滚动缓冲只保留最近 maxTicks 个 tick', () => {
  const { bot, recorder } = setup({ maxTicks: 3 });
  recorder.start();
  for (let i = 0; i < 10; i++) {
    tick(bot, { position: bot.entity.position.offset(0, 0, 1) });
  }
  const snap = recorder.snapshot();
  assert.strictEqual(snap.count, 3);
  assert.strictEqual(snap.ticks.length, 3);
});

test('snapshot 的 limit 只影响返回条数，不影响统计', () => {
  const { bot, recorder } = setup();
  recorder.start();
  bot.setControlState('forward', true);
  for (let i = 0; i < 5; i++) tick(bot, { position: bot.entity.position.offset(0, 0, 1) });

  const snap = recorder.snapshot({ limit: 2 });
  assert.strictEqual(snap.count, 5);
  assert.strictEqual(snap.returned, 2);
  assert.strictEqual(snap.ticks.length, 2);
  assert.strictEqual(snap.inputMovedTicks, 5);
});

test('给出时长后到点自动停止并摘监听', async () => {
  const { bot, recorder } = setup();
  recorder.start(0.05);
  assert.strictEqual(recorder.running, true);
  await new Promise((resolve) => setTimeout(resolve, 150));
  assert.strictEqual(recorder.running, false);
  assert.strictEqual(bot.listenerCount('physicsTick'), 0);
  assert.ok(recorder.snapshot().stoppedAt > 0);
});

test('录制时长被上限截断', () => {
  const { recorder } = setup();
  const result = recorder.start(9999);
  assert.match(result.message, /120 秒/);
  recorder.stop();
});

test('换 bot 时先收尾旧录制', () => {
  const { bot, recorder } = setup();
  recorder.start();
  tick(bot);
  const other = new FakeBot();
  recorder.setBot(other);
  assert.strictEqual(recorder.running, false, '换 bot 应停止录制');
  assert.strictEqual(recorder.snapshot().count, 1, '旧 bot 录到的内容保留');
  tick(bot);
  assert.strictEqual(recorder.snapshot().count, 1, '旧 bot 不再被记录');
});

test('clear 清空已录内容且不影响录制状态', () => {
  const { bot, recorder } = setup();
  recorder.start();
  tick(bot);
  assert.strictEqual(recorder.snapshot().count, 1);
  recorder.clear();
  const snap = recorder.snapshot();
  assert.strictEqual(snap.count, 0);
  assert.strictEqual(snap.running, true);
});

test('方块读不到（区块未加载）时记 null 而不是抛错', () => {
  const { bot, recorder } = setup();
  recorder.start();
  bot.blockAt = () => null;
  tick(bot);
  const row = recorder.snapshot().ticks[0];
  assert.strictEqual(row.blockBelow, null);
  assert.strictEqual(row.blockAtFeet, null);
});

test('录制自身出异常也不影响物理循环', () => {
  const { bot, recorder } = setup();
  recorder.start();
  // 位置是 NaN 时直接跳过，不抛错
  tick(bot, { position: { x: NaN, y: 0, z: 0 } });
  assert.strictEqual(recorder.snapshot().count, 0);

  // blockAt 抛错也不能让 physicsTick 崩
  bot.entity.position = { x: 1, y: 64, z: 1, offset: () => ({ x: 1, y: 63, z: 1 }) };
  bot.blockAt = () => {
    throw new Error('炸了');
  };
  assert.doesNotThrow(() => bot.emit('physicsTick'));
  const snap = recorder.snapshot();
  assert.strictEqual(snap.count, 1);
  assert.strictEqual(snap.ticks[0].blockBelow, null);
});

test('默认上限是一个合理的正数', () => {
  assert.ok(DEFAULT_MAX_TICKS >= 20);
  assert.strictEqual(new PhysicsRecorder().maxTicks, DEFAULT_MAX_TICKS);
});