import pkg/chronos
import pkg/asynctest/chronos/unittest
import pkg/questionable/results

import ./helpers

import pkg/codex/streams
import pkg/codex/stores
import pkg/codex/manifest
import pkg/codex/blocktype as bt

asyncchecksuite "StoreStream":
  var
    manifest: Manifest
    store: BlockStore
    stream: StoreStream

  # Check that `buf` contains `size` bytes with values start, start+1...
  proc sequentialBytes(buf: seq[byte], size: int, start: int): bool =
    for i in 0..<size:
      if int(buf[i]) != start+i:
        return false
    return true

  let
    data = [byte 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
            10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
            20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
            30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
            40, 41, 42, 43, 44, 45, 46, 47, 48, 49,
            50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
            60, 61, 62, 63, 64, 65, 66, 67, 68, 69,
            70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
            80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
            90, 91, 92, 93, 94, 95, 96, 97, 98, 99]
    chunkSize = 10

  teardown:
    await stream.close()

  setup:
    store = CacheStore.new()
    manifest = await storeDataGetManifest(store, MockChunker.new(dataset = data, chunkSize = chunkSize))
    stream = StoreStream.new(store, manifest)

  test "Read all blocks < blockSize":
    var
      buf = newSeq[byte](8)
      n = 0

    while not stream.atEof:
      let read = (await stream.readOnce(addr buf[0], buf.len))

      if not stream.atEof:
        check read == 8
      else:
        check read == 4

      check sequentialBytes(buf,read,n)
      n += read

  test "Read all blocks == blockSize":
    var
      buf = newSeq[byte](10)
      n = 0

    while not stream.atEof:
      let read = (await stream.readOnce(addr buf[0], buf.len))
      check read == 10
      check sequentialBytes(buf,read,n)
      n += read

  test "Read all blocks > blockSize":
    var
      buf = newSeq[byte](11)
      n = 0

    while not stream.atEof:
      let read = (await stream.readOnce(addr buf[0], buf.len))

      if not stream.atEof:
        check read == 11
      else:
        check read == 1

      check sequentialBytes(buf,read,n)
      n += read

  test "Read exact bytes within block boundary":
    var
      buf = newSeq[byte](5)

    await stream.readExactly(addr buf[0], 5)
    check sequentialBytes(buf,5,0)

  test "Read exact bytes outside of block boundary":
    var
      buf = newSeq[byte](15)

    await stream.readExactly(addr buf[0], 15)
    check sequentialBytes(buf,15,0)