'use strict';

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

const chunkPos = require('../src/core/chunkPos');

test('fromBlock 向下取整且兼容负数坐标', () => {
  assert.deepStrictEqual(chunkPos.fromBlock(0, 0), { x: 0, z: 0 });
  assert.deepStrictEqual(chunkPos.fromBlock(15, 15), { x: 0, z: 0 });
  assert.deepStrictEqual(chunkPos.fromBlock(16, 31), { x: 1, z: 1 });
  // 负数必须向下取整到更小的区块号，而不是向零取整
  assert.deepStrictEqual(chunkPos.fromBlock(-1, -16), { x: -1, z: -1 });
  assert.deepStrictEqual(chunkPos.fromBlock(-17, -33), { x: -2, z: -3 });
});

test('key/decode 往返一致（含负数与边界）', () => {
  const samples = [
    [0, 0], [1, 0], [0, 1], [-1, 0], [0, -1], [-1, -1],
    [1279, 1279], [-1280, -1280], [12345, -54321], [-2048, 2048]
  ];
  for (const [x, z] of samples) {
    const decoded = chunkPos.decode(chunkPos.key(x, z));
    assert.deepStrictEqual(decoded, { x, z }, `坐标 ${x},${z} 编解码不一致`);
  }
});

test('key 对不同坐标产生不同键', () => {
  const seen = new Set();
  for (let x = -50; x <= 50; x++) {
    for (let z = -50; z <= 50; z++) {
      const k = chunkPos.key(x, z);
      assert.ok(!seen.has(k), `键冲突：${x},${z}`);
      seen.add(k);
    }
  }
  assert.strictEqual(seen.size, 101 * 101);
});

test('centerBlock 取区块中心（+8）', () => {
  assert.strictEqual(chunkPos.centerBlockX(0), 8);
  assert.strictEqual(chunkPos.centerBlockX(-1), -8);
  assert.strictEqual(chunkPos.centerBlockZ(3), 56);
});

test('曼哈顿与切比雪夫距离', () => {
  assert.strictEqual(chunkPos.manhattan({ x: 0, z: 0 }, { x: 3, z: -4 }), 7);
  assert.strictEqual(chunkPos.chebyshev({ x: 0, z: 0 }, { x: 3, z: -4 }), 4);
  assert.strictEqual(chunkPos.chebyshev({ x: 5, z: 5 }, { x: 5, z: 5 }), 0);
});

test('equals 处理 null 与同值', () => {
  assert.strictEqual(chunkPos.equals({ x: 1, z: 2 }, { x: 1, z: 2 }), true);
  assert.strictEqual(chunkPos.equals({ x: 1, z: 2 }, { x: 2, z: 1 }), false);
  assert.strictEqual(chunkPos.equals(null, null), true);
  assert.strictEqual(chunkPos.equals({ x: 1, z: 2 }, null), false);
});

test('cardinalNeighbors 返回四个正方向邻居', () => {
  const neighbors = chunkPos.cardinalNeighbors(0, 0).map((c) => `${c.x},${c.z}`);
  assert.deepStrictEqual(neighbors.sort(), ['-1,0', '0,-1', '0,1', '1,0']);
});

test('withinWorldBorder 以 ±1280 为界', () => {
  assert.strictEqual(chunkPos.withinWorldBorder(0, 0), true);
  assert.strictEqual(chunkPos.withinWorldBorder(1279, -1280), true);
  assert.strictEqual(chunkPos.withinWorldBorder(1280, 0), false);
  assert.strictEqual(chunkPos.withinWorldBorder(0, -1281), false);
});