import { test } from '@japa/runner'
import { KEEPALIVE, decodeFrames, encodeFrame, isKeepalive } from '#lib/edge/index'

test.group('edge / stream frames', () => {
  test('frames survive being split anywhere; keep-alive frames are recognised', async ({ assert }) => {
    const whole = Buffer.concat([
      encodeFrame({ from: 160_000_000_001, to: 160_000_050_000, data: Buffer.from('first') }),
      encodeFrame(KEEPALIVE),
      encodeFrame({ from: 160_000_050_001, to: 160_000_100_000, data: Buffer.from('second chunk') }),
    ])
    const pieces = [whole.subarray(0, 7), whole.subarray(7, 30), whole.subarray(30)]
    const frames = []
    for await (const frame of decodeFrames(pieces)) frames.push(frame)
    assert.deepEqual(frames.map((f) => [f.from, f.to, f.data.toString(), isKeepalive(f)]), [
      [160_000_000_001, 160_000_050_000, 'first', false],
      [0, 0, '', true],
      [160_000_050_001, 160_000_100_000, 'second chunk', false],
    ])
  })

  test('a stream that ends inside a frame is an error', async ({ assert }) => {
    const cut = encodeFrame({ from: 1, to: 2, data: Buffer.from('abc') }).subarray(0, 21)
    await assert.rejects(async () => {
      for await (const _ of decodeFrames([cut])) {
      }
    }, /inside a frame/)
  })
  test('frames come out whole whatever the piece sizes, also pieces holding several frames', async ({ assert }) => {
    const sent = Array.from({ length: 12 }, (_, i) => ({ from: i * 10 + 1, to: i * 10 + 10, data: Buffer.alloc((i * 997) % 5000, i) }))
    const whole = Buffer.concat(sent.map(encodeFrame))
    for (const size of [1, 3, 20, 21, 64, 1000, 4096, whole.length]) {
      const pieces = []
      for (let at = 0; at < whole.length; at += size) pieces.push(new Uint8Array(whole.subarray(at, at + size)))
      const frames = []
      for await (const frame of decodeFrames(pieces)) frames.push(frame)
      assert.deepEqual(frames.map((f) => [f.from, f.to, f.data.toString('hex')]), sent.map((f) => [f.from, f.to, f.data.toString('hex')]), `pieces of ${size}`)
    }
  })
})