import { describe, expect, it } from 'vitest';
import { buildMultipart, makeBoundary } from '../src/core/multipart';
import { bytesIndexOf } from './fakes';

const enc = new TextEncoder();

function concat(...parts: Uint8Array[]): Uint8Array {
  const out = new Uint8Array(parts.reduce((n, p) => n + p.length, 0));
  let at = 0;
  for (const p of parts) {
    out.set(p, at);
    at += p.length;
  }
  return out;
}

describe('makeBoundary', () => {
  it('builds 24 hex chars from random()', () => {
    expect(makeBoundary(() => 0)).toBe(`----voice-note-${'0'.repeat(24)}`);
    expect(makeBoundary(() => 0.99)).toBe(`----voice-note-${'f'.repeat(24)}`);
  });

  it('clamps random() === 1 to f', () => {
    expect(makeBoundary(() => 1)).toBe(`----voice-note-${'f'.repeat(24)}`);
  });
});

describe('buildMultipart', () => {
  // Байты, которые сломались бы при прогоне через строку: 0x00, >0x7F, CRLF, "--".
  const audio = new Uint8Array([0x00, 0xff, 0x80, 0x0d, 0x0a, 0x2d, 0x2d]).buffer;
  const file = { name: 'file', filename: 'audio.m4a', contentType: 'audio/mp4', data: audio };

  it('builds exact bytes with the boundary from contentType', () => {
    const { body, contentType } = buildMultipart(
      [
        ['model', 'm1'],
        ['response_format', 'json'],
      ],
      file,
      'BND',
    );
    expect(contentType).toBe('multipart/form-data; boundary=BND');
    const expected = concat(
      enc.encode(
        '--BND\r\nContent-Disposition: form-data; name="model"\r\n\r\nm1\r\n' +
          '--BND\r\nContent-Disposition: form-data; name="response_format"\r\n\r\njson\r\n' +
          '--BND\r\nContent-Disposition: form-data; name="file"; filename="audio.m4a"\r\nContent-Type: audio/mp4\r\n\r\n',
      ),
      new Uint8Array(audio),
      enc.encode('\r\n--BND--\r\n'),
    );
    expect(new Uint8Array(body)).toEqual(expected);
  });

  it('keeps binary audio bytes unchanged', () => {
    const { body } = buildMultipart([], file, 'BND');
    expect(bytesIndexOf(new Uint8Array(body), new Uint8Array(audio))).toBeGreaterThan(0);
  });

  it('encodes non-ASCII field values as UTF-8', () => {
    const { body } = buildMultipart([['language', 'ру']], file, 'BND');
    expect(bytesIndexOf(new Uint8Array(body), enc.encode('\r\n\r\nру\r\n'))).toBeGreaterThan(0);
  });

  it('does not share memory with the input audio', () => {
    const data = new Uint8Array([1, 2, 3]);
    const { body } = buildMultipart([], { ...file, data: data.buffer }, 'BND');
    data[0] = 9;
    expect(bytesIndexOf(new Uint8Array(body), new Uint8Array([1, 2, 3]))).toBeGreaterThan(0);
  });
});