# beacon_chain
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

{.used.}

import
  options, sequtils, unittest, chronicles,
  ./testutil, ./testblockutil,
  ../beacon_chain/spec/[datatypes, digest],
  ../beacon_chain/[beacon_node_types, block_pool, beacon_chain_db, ssz]

suite "BlockRef and helpers" & preset():
  timedTest "isAncestorOf sanity" & preset():
    let
      s0 = BlockRef(slot: Slot(0))
      s1 = BlockRef(slot: Slot(1), parent: s0)
      s2 = BlockRef(slot: Slot(2), parent: s1)

    check:
      s0.isAncestorOf(s0)
      s0.isAncestorOf(s1)
      s0.isAncestorOf(s2)
      s1.isAncestorOf(s1)
      s1.isAncestorOf(s2)

      not s2.isAncestorOf(s0)
      not s2.isAncestorOf(s1)
      not s1.isAncestorOf(s0)

  timedTest "getAncestorAt sanity" & preset():
    let
      s0 = BlockRef(slot: Slot(0))
      s1 = BlockRef(slot: Slot(1), parent: s0)
      s2 = BlockRef(slot: Slot(2), parent: s1)
      s4 = BlockRef(slot: Slot(4), parent: s2)

    check:
      s0.getAncestorAt(Slot(0)) == s0
      s0.getAncestorAt(Slot(1)) == s0

      s1.getAncestorAt(Slot(0)) == s0
      s1.getAncestorAt(Slot(1)) == s1

      s4.getAncestorAt(Slot(0)) == s0
      s4.getAncestorAt(Slot(1)) == s1
      s4.getAncestorAt(Slot(2)) == s2
      s4.getAncestorAt(Slot(3)) == s2
      s4.getAncestorAt(Slot(4)) == s4

suite "BlockSlot and helpers" & preset():
  timedTest "atSlot sanity" & preset():
    let
      s0 = BlockRef(slot: Slot(0))
      s1 = BlockRef(slot: Slot(1), parent: s0)
      s2 = BlockRef(slot: Slot(2), parent: s1)
      s4 = BlockRef(slot: Slot(4), parent: s2)

    check:
      s0.atSlot(Slot(0)).blck == s0
      s0.atSlot(Slot(0)) == s1.atSlot(Slot(0))
      s1.atSlot(Slot(1)).blck == s1

      s4.atSlot(Slot(0)).blck == s0

  timedTest "parent sanity" & preset():
    let
      s0 = BlockRef(slot: Slot(0))
      s00 = BlockSlot(blck: s0, slot: Slot(0))
      s01 = BlockSlot(blck: s0, slot: Slot(1))
      s2 = BlockRef(slot: Slot(2), parent: s0)
      s22 = BlockSlot(blck: s2, slot: Slot(2))
      s24 = BlockSlot(blck: s2, slot: Slot(4))

    check:
      s00.parent == BlockSlot(blck: nil, slot: Slot(0))
      s01.parent == s00
      s22.parent == s01
      s24.parent == BlockSlot(blck: s2, slot: Slot(3))
      s24.parent.parent == s22

when const_preset == "minimal": # Too much stack space used on mainnet
  suite "Block pool processing" & preset():
    setup:
      var
        db = makeTestDB(SLOTS_PER_EPOCH)
        pool = BlockPool.init(db)
        state = pool.loadTailState().data.data
        b1 = addBlock(state, pool.tail.root, BeaconBlockBody())
        b1Root = hash_tree_root(b1.message)
        b2 = addBlock(state, b1Root, BeaconBlockBody())
        b2Root {.used.} = hash_tree_root(b2.message)

    timedTest "getRef returns nil for missing blocks":
      check:
        pool.getRef(default Eth2Digest) == nil

    timedTest "loadTailState gets genesis block on first load" & preset():
      let
        b0 = pool.get(pool.tail.root)

      check:
        b0.isSome()

    timedTest "Simple block add&get" & preset():
      let
        b1Add = pool.add(b1Root, b1)
        b1Get = pool.get(b1Root)

      check:
        b1Get.isSome()
        b1Get.get().refs.root == b1Root
        b1Add.root == b1Get.get().refs.root
        pool.heads.len == 1
        pool.heads[0].blck == b1Add

      let
        b2Add = pool.add(b2Root, b2)
        b2Get = pool.get(b2Root)

      check:
        b2Get.isSome()
        b2Get.get().refs.root == b2Root
        b2Add.root == b2Get.get().refs.root
        pool.heads.len == 1
        pool.heads[0].blck == b2Add

    timedTest "Reverse order block add & get" & preset():
      discard pool.add(b2Root, b2)

      check:
        pool.get(b2Root).isNone() # Unresolved, shouldn't show up
        FetchRecord(root: b1Root, historySlots: 1) in pool.checkMissing()

      discard pool.add(b1Root, b1)

      let
        b1Get = pool.get(b1Root)
        b2Get = pool.get(b2Root)

      check:
        b1Get.isSome()
        b2Get.isSome()

        b1Get.get().refs.children[0] == b2Get.get().refs
        b2Get.get().refs.parent == b1Get.get().refs

      pool.updateHead(b2Get.get().refs)

      # The heads structure should have been updated to contain only the new
      # b2 head
      check:
        pool.heads.mapIt(it.blck) == @[b2Get.get().refs]

      # check that init also reloads block graph
      var
        pool2 = BlockPool.init(db)

      check:
        # ensure we loaded the correct head state
        pool2.head.blck.root == b2Root
        hash_tree_root(pool2.headState.data.data) == b2.message.state_root
        pool2.get(b1Root).isSome()
        pool2.get(b2Root).isSome()
        pool2.heads.len == 1
        pool2.heads[0].blck.root == b2Root

    timedTest "Can add same block twice" & preset():
      let
        b10 = pool.add(b1Root, b1)
        b11 = pool.add(b1Root, b1)

      check:
        b10 == b11
        not b10.isNil

    timedTest "updateHead updates head and headState" & preset():
      let
        b1Add = pool.add(b1Root, b1)

      pool.updateHead(b1Add)

      check:
        pool.head.blck == b1Add
        pool.headState.data.data.slot == b1Add.slot