{.used.}

import
  std/[options, sequtils, algorithm],
  testutils/unittests, 
  libp2p/protobuf/minprotobuf
import
  ../../waku/v2/node/message_store/queue_store/queue_store {.all.},
  ../../waku/v2/node/message_store/queue_store/index,
  ../../waku/v2/protocol/waku_store,
  ../../waku/v2/protocol/waku_message,
  ../../waku/v2/utils/time,
  ./testlib/common


proc getTestStoreQueue(numMessages: int): StoreQueueRef =
  let testStoreQueue = StoreQueueRef.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 testStoreQueue.add(msg)
  
  return testStoreQueue


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

  test "Forward pagination - normal pagination":
    ## Given
    let
      pageSize: uint64 = 2 
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true
    
    ## When
    let page = store.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: uint64 = 2 
      cursor: Option[Index] = none(Index)
      forward: bool = true
    
    ## When
    let page = store.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: uint64 = 13
      cursor: Option[Index] = none(Index)
      forward: bool = true
    
    ## When
    let page = store.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 store = getTestStoreQueue(0)
    let
      pageSize: uint64 = 2 
      cursor: Option[Index] = none(Index)
      forward: bool = true

    ## When
    let page = store.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: uint64 = 10
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true

    ## When
    let page = store.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: uint64 = MaxPageSize + 1
      cursor: Option[Index] = some(indexList[3])
      forward: bool = true

    ## When
    let page = store.getPage(pageSize=pageSize, forward=forward, cursor=cursor)
    
    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      uint64(data.len) <= MaxPageSize
  
  test "Forward pagination - cursor pointing to the end of the message list":
    ## Given
    let
      pageSize: uint64 = 10
      cursor: Option[Index] = some(indexList[9])
      forward: bool = true

    ## When
    let page = store.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 = HistoryCursor(
      pubsubTopic: DefaultPubsubTopic,
      senderTime: msg.timestamp,
      storeTime: msg.timestamp,
      digest: computeDigest(msg)
    ).toIndex()

    let
      pageSize: uint64 = 10 
      cursor: Option[Index] = some(index)
      forward: bool = true

    ## When
    let page = store.getPage(pageSize=pageSize, forward=forward, cursor=cursor)
    
    ## Then
    let error = page.tryError()
    check:
      error == StoreQueueErrorKind.INVALID_CURSOR
  
  test "Forward pagination - initial paging query over a message list with one message":
    ## Given
    let store = getTestStoreQueue(1)
    let
      pageSize: uint64 = 10
      cursor: Option[Index] = none(Index)
      forward: bool = true
    
    ## When
    let page = store.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 store = getTestStoreQueue(1)
    let
      pageSize: uint64 = 10
      cursor: Option[Index] = some(indexList[0])
      forward: bool = true

    ## When
    let page = store.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: uint64 = 3
      cursor: Option[Index] = none(Index)
      forward = true

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

    ## When
    let page = store.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: uint64 = 2 
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false
    
    ## When
    let page = store.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 store = getTestStoreQueue(0)
    let
      pageSize: uint64 = 2 
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = store.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: uint64 = 2 
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = store.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: uint64 = 13
      cursor: Option[Index] = none(Index)
      forward: bool = false
    
    ## When
    let page = store.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: uint64 = 5
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false

    ## When
    let page = store.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: uint64 = MaxPageSize + 1
      cursor: Option[Index] = some(indexList[3])
      forward: bool = false

    ## When
    let page = store.getPage(pageSize=pageSize, forward=forward, cursor=cursor)
    
    ## Then
    let data = page.tryGet().mapIt(it[1])
    check:
      uint64(data.len) <= MaxPageSize

  test "Backward pagination - cursor pointing to the begining of the message list":
    ## Given
    let
      pageSize: uint64 = 5
      cursor: Option[Index] = some(indexList[0])
      forward: bool = false

    ## When
    let page = store.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 = HistoryCursor(
      pubsubTopic: DefaultPubsubTopic,
      senderTime: msg.timestamp,
      storeTime: msg.timestamp,
      digest: computeDigest(msg)
    ).toIndex()

    let
      pageSize: uint64 = 2 
      cursor: Option[Index] = some(index)
      forward: bool = false

    ## When
    let page = store.getPage(pageSize=pageSize, forward=forward, cursor=cursor)
    
    ## Then
    let error = page.tryError()
    check:
      error == StoreQueueErrorKind.INVALID_CURSOR
    
  test "Backward pagination - initial paging query over a message list with one message":
    ## Given
    let store = getTestStoreQueue(1)
    let
      pageSize: uint64 = 10
      cursor: Option[Index] = none(Index)
      forward: bool = false

    ## When
    let page = store.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 store = getTestStoreQueue(1)
    let
      pageSize: uint64 = 10
      cursor: Option[Index] = some(indexList[0])
      forward: bool = false

    ## When
    let page = store.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: uint64 = 3
      cursor: Option[Index] = none(Index)
      forward = false

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

    ## When
    let page = store.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