import pkg/chronos
import pkg/questionable/results

import pkg/codex/[
  streams,
  stores,
  indexingstrategy,
  manifest,
  blocktype as bt]

import ../asynctest
import ./examples
import ./helpers

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)

suite "StoreStream - Size Tests":

  var stream: StoreStream

  teardown:
    await stream.close()

  test "Should return dataset size as stream size":
    let manifest = Manifest.new(
      treeCid = Cid.example,
      datasetSize = 80.NBytes,
      blockSize = 10.NBytes
    )

    stream = StoreStream.new(CacheStore.new(), manifest)

    check stream.size == 80

  test "Should not count parity/padding bytes as part of stream size":
    let protectedManifest = Manifest.new(
      treeCid = Cid.example,
      datasetSize = 120.NBytes, # size including parity bytes
      blockSize = 10.NBytes,
      version = CIDv1,
      hcodec = Sha256HashCodec,
      codec = BlockCodec,
      ecK = 2,
      ecM = 1,
      originalTreeCid = Cid.example,
      originalDatasetSize = 80.NBytes, # size without parity bytes
      strategy = StrategyType.SteppedStrategy
    )

    stream = StoreStream.new(CacheStore.new(), protectedManifest)

    check stream.size == 80