import { mkdtempSync, rmSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { afterEach, describe, expect, it } from 'vitest';
import { samplePointcloudFile } from './pointcloudSample';

const temporaryDirectories: string[] = [];

afterEach(() => {
  while (temporaryDirectories.length > 0) {
    rmSync(temporaryDirectories.pop()!, { recursive: true, force: true });
  }
});

function writeBinaryPly(properties: string[], records: number[][]): string {
  const directory = mkdtempSync(join(tmpdir(), 'pointcloud-sample-'));
  temporaryDirectories.push(directory);
  const filePath = join(directory, 'cloud.ply');
  const header = Buffer.from([
    'ply',
    'format binary_little_endian 1.0',
    `element vertex ${records.length}`,
    ...properties.map((name) => `property float ${name}`),
    'end_header',
    '',
  ].join('\n'), 'ascii');
  const body = Buffer.alloc(records.length * properties.length * 4);
  records.forEach((record, recordIndex) => {
    record.forEach((value, propertyIndex) => {
      body.writeFloatLE(value, (recordIndex * properties.length + propertyIndex) * 4);
    });
  });
  writeFileSync(filePath, Buffer.concat([header, body]));
  return filePath;
}

describe('samplePointcloudFile', () => {
  it('不会为只有 xyz 的输入点云伪造误差', async () => {
    const filePath = writeBinaryPly(
      ['x', 'y', 'z'],
      [[1, 2, 3], [4, 5, 6]],
    );

    const points = await samplePointcloudFile(filePath, 1_000, 2);

    expect(points).toHaveLength(2);
    expect(points.every((point) => point.error === undefined)).toBe(true);
  });

  it.each(['error', 'deviation'])('保留 PLY 中真实的 %s 属性', async (errorProperty) => {
    const filePath = writeBinaryPly(
      ['x', 'y', 'z', errorProperty],
      [[1, 2, 3, 0.25], [4, 5, 6, -0.5]],
    );

    const points = await samplePointcloudFile(filePath, 1_000, 2);

    expect(points.map((point) => point.error)).toEqual([0.25, -0.5]);
  });
});