feat: incentivization PoC: client-side reputation system basics (#3293)

* chore: rename test file for eligibility tests

* add reputation manager

* add simple boolean reputation with dummy response

* set default reputation to true

* use reputation indicator term; remove unnecessary updateReputation

* use PushResponse in reputation manager

* add custom type for reputation

* add reputation update from response quality

* encode reputation indicators as Option[bool]

tests/incentivization/test_all.nim

@@ -1 +1 @@
-import ./test_rpc_codec, ./test_poc
+import ./test_rpc_codec, ./test_poc_eligibility, ./test_poc_reputation

tests/incentivization/test_poc_reputation.nim

@@ -0,0 +1,54 @@
+import
+  std/options,
+  testutils/unittests,
+  chronos,
+  web3,
+  stew/byteutils,
+  stint,
+  strutils,
+  tests/testlib/testasync
+
+import
+  waku/[node/peer_manager, waku_core],
+  waku/incentivization/[rpc, reputation_manager],
+  waku/waku_lightpush/rpc
+
+suite "Waku Incentivization PoC Reputation":
+  var manager {.threadvar.}: ReputationManager
+
+  setup:
+    manager = ReputationManager.init()
+
+  test "incentivization PoC: reputation: reputation table is empty after initialization":
+    check manager.reputationOf.len == 0
+
+  test "incentivization PoC: reputation: set and get reputation":
+    manager.setReputation("peer1", some(true)) # Encodes GoodRep
+    check manager.getReputation("peer1") == some(true)
+
+  test "incentivization PoC: reputation: evaluate PushResponse valid":
+    let validLightpushResponse =
+      PushResponse(isSuccess: true, info: some("Everything is OK"))
+    # We expect evaluateResponse to return GoodResponse if isSuccess is true
+    check evaluateResponse(validLightpushResponse) == GoodResponse
+
+  test "incentivization PoC: reputation: evaluate PushResponse invalid":
+    let invalidLightpushResponse = PushResponse(isSuccess: false, info: none(string))
+    check evaluateResponse(invalidLightpushResponse) == BadResponse
+
+  test "incentivization PoC: reputation: updateReputationFromResponse valid":
+    let peerId = "peerWithValidResponse"
+    let validResp = PushResponse(isSuccess: true, info: some("All good"))
+    manager.updateReputationFromResponse(peerId, validResp)
+    check manager.getReputation(peerId) == some(true)
+
+  test "incentivization PoC: reputation: updateReputationFromResponse invalid":
+    let peerId = "peerWithInvalidResponse"
+    let invalidResp = PushResponse(isSuccess: false, info: none(string))
+    manager.updateReputationFromResponse(peerId, invalidResp)
+    check manager.getReputation(peerId) == some(false)
+
+  test "incentivization PoC: reputation: default is None":
+    let unknownPeerId = "unknown_peer"
+    # The peer is not in the table yet
+    check manager.getReputation(unknownPeerId) == none(bool)

waku/incentivization/reputation_manager.nim

@@ -0,0 +1,48 @@
+import tables, std/options
+import waku/waku_lightpush/rpc
+
+type
+  PeerId = string
+
+  ResponseQuality* = enum
+    BadResponse
+    GoodResponse
+
+  # Encode reputation indicator as Option[bool]:
+  #   some(true)  => GoodRep
+  #   some(false) => BadRep
+  #   none(bool)  => unknown / not set
+  ReputationManager* = ref object
+    reputationOf*: Table[PeerId, Option[bool]]
+
+proc init*(T: type ReputationManager): ReputationManager =
+  return ReputationManager(reputationOf: initTable[PeerId, Option[bool]]())
+
+proc setReputation*(
+    manager: var ReputationManager, peer: PeerId, repValue: Option[bool]
+) =
+  manager.reputationOf[peer] = repValue
+
+proc getReputation*(manager: ReputationManager, peer: PeerId): Option[bool] =
+  if peer in manager.reputationOf:
+    result = manager.reputationOf[peer]
+  else:
+    result = none(bool)
+
+# Evaluate the quality of a PushResponse by checking its isSuccess field
+proc evaluateResponse*(response: PushResponse): ResponseQuality =
+  if response.isSuccess:
+    return GoodResponse
+  else:
+    return BadResponse
+
+# Update reputation of the peer based on the quality of the response
+proc updateReputationFromResponse*(
+    manager: var ReputationManager, peer: PeerId, response: PushResponse
+) =
+  let respQuality = evaluateResponse(response)
+  case respQuality
+  of BadResponse:
+    manager.setReputation(peer, some(false)) # false => BadRep
+  of GoodResponse:
+    manager.setReputation(peer, some(true)) # true  => GoodRep