nim-codex/tests/codex/slots/sampler/testsampler.nim

import std/sequtils
import std/options
import std/importutils

import ../../../asynctest

import pkg/questionable
import pkg/questionable/results
import pkg/datastore

import pkg/codex/rng
import pkg/codex/stores
import pkg/codex/merkletree
import pkg/codex/utils/json
import pkg/codex/codextypes
import pkg/codex/slots
import pkg/codex/slots/builder
import pkg/codex/utils/poseidon2digest
import pkg/codex/slots/sampler/utils

import pkg/constantine/math/arithmetic
import pkg/constantine/math/io/io_bigints
import pkg/constantine/math/io/io_fields

import ../backends/helpers
import ../helpers
import ../../helpers

suite "Test Sampler - control samples":

  var
    inputData: string
    inputJson: JsonNode
    proofInput: ProofInputs[Poseidon2Hash]

  setup:
    inputData = readFile("tests/circuits/fixtures/input.json")
    inputJson = !JsonNode.parse(inputData)
    proofInput = Poseidon2Hash.jsonToProofInput(inputJson)

  test "Should verify control samples":
    let
      blockCells = 32
      cellIdxs = proofInput.entropy.cellIndices(proofInput.slotRoot, proofInput.nCellsPerSlot, 5)

    for i, cellIdx in cellIdxs:
      let
        sample = proofInput.samples[i]
        cellIdx = cellIdxs[i]

        cellProof = Poseidon2Proof.init(
          cellIdx.toCellInBlk(blockCells),
          proofInput.nCellsPerSlot,
          sample.merklePaths[0..<5]).tryGet

        slotProof = Poseidon2Proof.init(
          cellIdx.toBlkInSlot(blockCells),
          proofInput.nCellsPerSlot,
          sample.merklePaths[5..<9]).tryGet

        cellData = sample.cellData
        cellLeaf = Poseidon2Hash.spongeDigest(cellData, rate = 2).tryGet
        slotLeaf = cellProof.reconstructRoot(cellLeaf).tryGet

      check slotProof.verify(slotLeaf, proofInput.slotRoot).tryGet

  test "Should verify control dataset root":
    let
      datasetProof = Poseidon2Proof.init(
        proofInput.slotIndex,
        proofInput.nSlotsPerDataSet,
        proofInput.slotProof[0..<4]).tryGet

    check datasetProof.verify(proofInput.slotRoot, proofInput.datasetRoot).tryGet

suite "Test Sampler":

  let
    slotIndex     = 3
    nSamples      = 5
    ecK           = 3
    ecM           = 2
    datasetBlocks = 8
    entropy       = 1234567.toF
    blockSize     = DefaultBlockSize
    cellSize      = DefaultCellSize
    repoTmp = TempLevelDb.new()
    metaTmp = TempLevelDb.new()

  var
    store: RepoStore
    builder: Poseidon2Builder
    manifest: Manifest
    protected: Manifest
    verifiable: Manifest

  setup:
    let
      repoDs = repoTmp.newDb()
      metaDs = metaTmp.newDb()

    store = RepoStore.new(repoDs, metaDs)

    (manifest, protected, verifiable) =
        await createVerifiableManifest(
          store,
          datasetBlocks,
          ecK, ecM,
          blockSize,
          cellSize)

    # create sampler
    builder = Poseidon2Builder.new(store, verifiable).tryGet

  teardown:
    await store.close()
    await repoTmp.destroyDb()
    await metaTmp.destroyDb()

  test "Should fail instantiating for invalid slot index":
    let
      sampler = Poseidon2Sampler.new(builder.slotRoots.len, store, builder)

    check sampler.isErr

  test "Should fail instantiating for non verifiable builder":
    let
      nonVerifiableBuilder = Poseidon2Builder.new(store, protected).tryGet
      sampler = Poseidon2Sampler.new(slotIndex, store, nonVerifiableBuilder)

    check sampler.isErr

  test "Should verify samples":
    let
      sampler = Poseidon2Sampler.new(slotIndex, store, builder).tryGet

      verifyTree  = builder.verifyTree.get                  # get the dataset tree
      slotProof   = verifyTree.getProof(slotIndex).tryGet   # get slot proof for index
      datasetRoot = verifyTree.root().tryGet                # get dataset root
      slotTreeCid = verifiable.slotRoots[slotIndex]         # get slot tree cid to retrieve proof from storage
      slotRoot    = builder.slotRoots[slotIndex]            # get slot root hash
      cellIdxs    = entropy.cellIndices(slotRoot, builder.numSlotCells, nSamples)

      nBlockCells = builder.numBlockCells
      nSlotCells  = builder.numSlotCells

    for i, cellIdx in cellIdxs:
      let
        sample = (await sampler.getSample(cellIdx, slotTreeCid, slotRoot)).tryGet

        cellProof = Poseidon2Proof.init(
          cellIdx.toCellInBlk(nBlockCells),
          nSlotCells,
          sample.merklePaths[0..<5]).tryGet

        slotProof = Poseidon2Proof.init(
          cellIdx.toBlkInSlot(nBlockCells),
          nSlotCells,
          sample.merklePaths[5..<sample.merklePaths.len]).tryGet

        cellData = sample.cellData
        cellLeaf = Poseidon2Hash.spongeDigest(cellData, rate = 2).tryGet
        slotLeaf = cellProof.reconstructRoot(cellLeaf).tryGet

      check slotProof.verify(slotLeaf, slotRoot).tryGet

  test "Should verify dataset root":
    let
      sampler = Poseidon2Sampler.new(slotIndex, store, builder).tryGet
      proofInput = (await sampler.getProofInput(entropy.toBytes.toArray32, nSamples)).tryGet

      datasetProof = Poseidon2Proof.init(
          proofInput.slotIndex,
          builder.slotRoots.len,
          proofInput.slotProof).tryGet

    check datasetProof.verify(builder.slotRoots[slotIndex], builder.verifyRoot.get).tryGet