{.used.}

import
  std/[options, sequtils, algorithm],
  testutils/unittests,
  libp2p/protobuf/minprotobuf
import
  ../../../waku/v2/protocol/waku_archive,
  ../../../waku/v2/protocol/waku_archive/driver/queue_driver/queue_driver {.all.},
  ../../../waku/v2/protocol/waku_archive/driver/queue_driver/index,
  ../../../waku/v2/protocol/waku_message,
  ../../../waku/v2/utils/time,
  ../testlib/common,
  ../testlib/waku2


proc getTestQueueDriver(numMessages: int): QueueDriver =
  let testQueueDriver = QueueDriver.new(numMessages)

  var data {.noinit.}: array[32, byte]
  for x in data.mitems: x = 1

  for i in 0..<numMessages:
    let msg = IndexedWakuMessage(
      msg: WakuMessage(payload: @[byte i], timestamp: Timestamp(i)),
      index: Index(
        receiverTime: Timestamp(i),
        senderTime: Timestamp(i),
        digest: MessageDigest(data: data)
      )
    )
    discard testQueueDriver.add(msg)

  return testQueueDriver


procSuite "Queue driver - pagination":
  let driver = getTestQueueDriver(10)
  let
    indexList: seq[Index] = toSeq(driver.fwdIterator()).mapIt(it[0])
    msgList: seq[WakuMessage] = toSeq(driver.fwdIterator()).mapIt(it[1].msg)

  test "Forward pagination - normal pagination":
    ## Given
    let
      pageSize: uint = 2
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 2
      data == msgList[4..5]

  test "Forward pagination - initial pagination request with an empty cursor":
    ## Given
    let
      pageSize: uint = 2
      cursor: Option[Index] = none(Index)
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 2
      data == msgList[0..1]

  test "Forward pagination - initial pagination request with an empty cursor to fetch the entire history":
    ## Given
    let
      pageSize: uint = 13
      cursor: Option[Index] = none(Index)
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 10
      data == msgList[0..9]

  test "Forward pagination - empty msgList":
    ## Given
    let driver = getTestQueueDriver(0)
    let
      pageSize: uint = 2
      cursor: Option[Index] = none(Index)
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Forward pagination - page size larger than the remaining messages":
    ## Given
    let
      pageSize: uint = 10
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 6
      data == msgList[4..9]

  test "Forward pagination - page size larger than the maximum allowed page size":
    ## Given
    let
      pageSize: uint = MaxPageSize + 1
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      uint(data.len) <= MaxPageSize

  test "Forward pagination - cursor pointing to the end of the message list":
    ## Given
    let
      pageSize: uint = 10
      cursor: Option[Index] = some(indexList[9])
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Forward pagination - invalid cursor":
    ## Given
    let msg = fakeWakuMessage(payload= @[byte 10])
    let index = ArchiveCursor(
      pubsubTopic: DefaultPubsubTopic,
      senderTime: msg.timestamp,
      storeTime: msg.timestamp,
      digest: computeDigest(msg)
    ).toIndex()

    let
      pageSize: uint = 10
      cursor: Option[Index] = some(index)
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let error = page.tryError()
    check:
      error == QueueDriverErrorKind.INVALID_CURSOR

  test "Forward pagination - initial paging query over a message list with one message":
    ## Given
    let driver = getTestQueueDriver(1)
    let
      pageSize: uint = 10
      cursor: Option[Index] = none(Index)
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 1

  test "Forward pagination - pagination over a message list with one message":
    ## Given
    let driver = getTestQueueDriver(1)
    let
      pageSize: uint = 10
      cursor: Option[Index] = some(indexList[0])
      forward: bool = true

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Forward pagination - with pradicate":
    ## Given
    let
      pageSize: uint = 3
      cursor: Option[Index] = none(Index)
      forward = true

    proc onlyEvenTimes(i: IndexedWakuMessage): bool = i.msg.timestamp.int64 mod 2 == 0

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor, predicate=onlyEvenTimes)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.mapIt(it.timestamp.int) == @[0, 2, 4]


  test "Backward pagination - normal pagination":
    ## Given
    let
      pageSize: uint = 2
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data == msgList[1..2].reversed

  test "Backward pagination - empty msgList":
    ## Given
    let driver = getTestQueueDriver(0)
    let
      pageSize: uint = 2
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Backward pagination - initial pagination request with an empty cursor":
    ## Given
    let
      pageSize: uint = 2
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 2
      data == msgList[8..9].reversed

  test "Backward pagination - initial pagination request with an empty cursor to fetch the entire history":
    ## Given
    let
      pageSize: uint = 13
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 10
      data == msgList[0..9].reversed

  test "Backward pagination - page size larger than the remaining messages":
    ## Given
    let
      pageSize: uint = 5
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data == msgList[0..2].reversed

  test "Backward pagination - page size larger than the Maximum allowed page size":
    ## Given
    let
      pageSize: uint = MaxPageSize + 1
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      uint(data.len) <= MaxPageSize

  test "Backward pagination - cursor pointing to the begining of the message list":
    ## Given
    let
      pageSize: uint = 5
      cursor: Option[Index] = some(indexList[0])
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Backward pagination - invalid cursor":
    ## Given
    let msg = fakeWakuMessage(payload= @[byte 10])
    let index = ArchiveCursor(
      pubsubTopic: DefaultPubsubTopic,
      senderTime: msg.timestamp,
      storeTime: msg.timestamp,
      digest: computeDigest(msg)
    ).toIndex()

    let
      pageSize: uint = 2
      cursor: Option[Index] = some(index)
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let error = page.tryError()
    check:
      error == QueueDriverErrorKind.INVALID_CURSOR

  test "Backward pagination - initial paging query over a message list with one message":
    ## Given
    let driver = getTestQueueDriver(1)
    let
      pageSize: uint = 10
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 1

  test "Backward pagination - paging query over a message list with one message":
    ## Given
    let driver = getTestQueueDriver(1)
    let
      pageSize: uint = 10
      cursor: Option[Index] = some(indexList[0])
      forward: bool = false

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.len == 0

  test "Backward pagination - with predicate":
    ## Given
    let
      pageSize: uint = 3
      cursor: Option[Index] = none(Index)
      forward = false

    proc onlyOddTimes(i: IndexedWakuMessage): bool = i.msg.timestamp.int64 mod 2 != 0

    ## When
    let page = driver.getPage(pageSize=pageSize, forward=forward, cursor=cursor, predicate=onlyOddTimes)

    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      data.mapIt(it.timestamp.int) == @[5, 7,9].reversed