const test = require('node:test');
const assert = require('node:assert/strict');
const { hello, jpegSize } = require('../lib/printerCamera');

test('the camera hello carries the username and code in the right places', () => {
  const buf = hello('12345678');
  assert.equal(buf.length, 80);
  assert.equal(buf.readUInt32LE(0), 0x40);
  assert.equal(buf.readUInt32LE(4), 0x3000);
  assert.equal(buf.subarray(16, 20).toString('ascii'), 'bblp');
  assert.equal(buf.subarray(16, 48).toString('ascii').replace(/\0+$/, ''), 'bblp');
  assert.equal(buf.subarray(48, 80).toString('ascii').replace(/\0+$/, ''), '12345678');
});

test('a frame’s size is read from the JPEG itself', () => {
  // A JPEG header: start marker, a comment segment, then the frame header.
  const jpeg = Buffer.concat([
    Buffer.from([0xff, 0xd8]),
    Buffer.from([0xff, 0xfe, 0x00, 0x04, 0x61, 0x62]),           // comment, skipped
    Buffer.from([0xff, 0xc0, 0x00, 0x11, 0x08, 0x04, 0x38, 0x07, 0x80]), // 1080 × 1920
  ]);
  assert.deepEqual(jpegSize(jpeg), { height: 1080, width: 1920 });
  assert.equal(jpegSize(Buffer.from([0xff, 0xd8, 0x00])), null);
});