feat(node): integration rewards, review comments.

contracts/contracts/activities/Activity.sol

@@ -3,55 +3,63 @@ pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
 
-event ActivityReportCreated(uint64 checkpointHeight, ActivityReport report);
+// Event to be emitted within the subnet when a new activity summary has been recorded.
+event ActivityRollupRecorded(uint64 checkpointHeight, FullActivityRollup rollup);
 
-/// The full validator activities report
-struct ActivityReport {
-    ValidatorActivityReport[] validators;
+// Carries a set of reports summarising various aspects of the activity that took place in the subnet between the
+// previous checkpoint and the checkpoint this summary is committed into. If this is the first checkpoint, the summary
+// contains information about the subnet's activity since genesis.
+// In the future we'll be having more kinds of activity reports here.
+struct FullActivityRollup {
+    /// A report of consensus-level activity that took place in the subnet between the previous checkpoint
+    /// and the checkpoint this summary is committed into.
+    /// @dev If there is a configuration change applied at this checkpoint, this carries information
+    /// about the _old_ validator set.
+    Consensus.FullSummary consensus;
 }
 
-struct ValidatorActivityReport {
-    /// @dev The validator whose activity we're reporting about.
-    address validator;
-    /// @dev The number of blocks committed by each validator in the position they appear in the validators array.
-    /// If there is a configuration change applied at this checkpoint, this carries information about the _old_ validator set.
-    uint64 blocksCommitted;
-    /// @dev Other metadata
-    bytes metadata;
+// Compressed representation of the activity summary that can be embedded in checkpoints to propagate up the hierarchy.
+struct CompressedActivityRollup {
+    Consensus.CompressedSummary consensus;
 }
 
-/// The summary for the child subnet activities that should be submitted to the parent subnet
-/// together with a bottom up checkpoint
-struct ActivitySummary {
-    /// The total number of distintive validators that have mined
-    uint64 totalActiveValidators;
-    /// The activity commitment for validators
-    bytes32 commitment;
+/// Namespace for consensus-level activity summaries.
+library Consensus {
+    type MerkleHash is bytes32;
 
-    // TODO: add relayed rewarder commitment
-}
+    // Aggregated stats for consensus-level activity.
+    struct AggregatedStats {
+        /// The total number of unique validators that have mined within this period.
+        uint64 totalActiveValidators;
+        /// The total number of blocks committed by all validators during this period.
+        uint64 totalNumBlocksCommitted;
+    }
 
-/// The summary for a single validator
-struct ValidatorSummary {
-    /// @dev The child subnet checkpoint height associated with this summary
-    uint64 checkpointHeight;
-    /// @dev The validator whose activity we're reporting about.
-    address validator;
-    /// @dev The number of blocks committed by each validator in the position they appear in the validators array.
-    /// If there is a configuration change applied at this checkpoint, this carries information about the _old_ validator set.
-    uint64 blocksCommitted;
-    /// @dev Other metadata
-    bytes metadata;
-}
+    // The full activity summary for consensus-level activity.
+    struct FullSummary {
+        AggregatedStats stats;
+        /// The breakdown of activity per validator.
+        ValidatorData[] data;
+    }
 
-/// The proof required for validators to claim rewards
-struct ValidatorClaimProof {
-    ValidatorSummary summary;
-    bytes32[] proof;
-}
+    // The compresed representation of the activity summary for consensus-level activity suitable for embedding in a checkpoint.
+    struct CompressedSummary {
+        AggregatedStats stats;
+        /// The commitment for the validator details, so that we don't have to transmit them in full.
+        MerkleHash dataRootCommitment;
+    }
+
+    struct ValidatorData {
+        /// @dev The validator whose activity we're reporting about, identified by the Ethereum address corresponding
+        /// to its secp256k1 pubkey.
+        address validator;
+        /// @dev The number of blocks committed by this validator during the summarised period.
+        uint64 blocksCommitted;
+    }
 
-/// The proofs to batch claim validator rewards in a specific subnet
-struct BatchClaimProofs {
-    SubnetID subnetId;
-    ValidatorClaimProof[] proofs;
+    /// The payload for validators to claim rewards
+    struct ValidatorClaim {
+        ValidatorData data;
+        MerkleHash[] proof;
+    }
 }

contracts/contracts/activities/IValidatorRewarder.sol

@@ -2,7 +2,7 @@
 pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
-import {ValidatorSummary} from "./Activity.sol";
+import {Consensus} from "./Activity.sol";
 
 /// @title ValidatorRewarder interface.
 ///
@@ -14,7 +14,7 @@ interface IValidatorRewarder {
     /// @notice Called by the subnet manager contract to instruct the rewarder to process the subnet summary and
     /// disburse any relevant rewards.
     /// @dev This method should revert if the summary is invalid; this will cause the
-    function disburseRewards(SubnetID calldata id, ValidatorSummary calldata summary) external;
+    function disburseRewards(SubnetID calldata id, Consensus.ValidatorData calldata detail) external;
 }
 
 /// @title Validator reward setup interface

contracts/contracts/activities/LibActivityMerkleVerifier.sol

@@ -3,25 +3,24 @@ pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
 import {InvalidProof} from "../errors/IPCErrors.sol";
-import {ValidatorSummary} from "./Activity.sol";
+import {Consensus} from "./Activity.sol";
 import {MerkleProof} from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
 
 /// Verifies the proof to the commitment in subnet activity summary
 library LibActivityMerkleVerifier {
     function ensureValidProof(
         bytes32 commitment,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal pure {
         // Constructing leaf: https://github.com/OpenZeppelin/merkle-tree#leaf-hash
-        bytes32 leaf = keccak256(
-            bytes.concat(
-                keccak256(
-                    abi.encode(summary.validator, summary.blocksCommitted, summary.metadata)
-                )
-            )
-        );
-        bool valid = MerkleProof.verify({proof: proof, root: commitment, leaf: leaf});
+        bytes32 leaf = keccak256(bytes.concat(keccak256(abi.encode(detail.validator, detail.blocksCommitted))));
+        // converting proof to bytes32[]
+        bytes32[] memory proofBytes = new bytes32[](proof.length);
+        for (uint256 i = 0; i < proof.length; i++) {
+            proofBytes[i] = Consensus.MerkleHash.unwrap(proof[i]);
+        }
+        bool valid = MerkleProof.verify({proof: proofBytes, root: commitment, leaf: leaf});
         if (!valid) {
             revert InvalidProof();
         }

contracts/contracts/activities/ValidatorRewardFacet.sol

@@ -1,27 +1,32 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 pragma solidity ^0.8.23;
 
-import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
-import {EnumerableMap} from "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";
+import {Consensus} from "./Activity.sol";
 
+import {EnumerableMap} from "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";
+import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
+import {IValidatorRewarder, IValidatorRewardSetup} from "./IValidatorRewarder.sol";
+import {LibActivityMerkleVerifier} from "./LibActivityMerkleVerifier.sol";
+import {LibDiamond} from "../lib/LibDiamond.sol";
+import {NotValidator, SubnetNoTargetCommitment, CommitmentAlreadyInitialized, ValidatorAlreadyClaimed, NotGateway, NotOwner} from "../errors/IPCErrors.sol";
 import {Pausable} from "../lib/LibPausable.sol";
 import {ReentrancyGuard} from "../lib/LibReentrancyGuard.sol";
-import {NotValidator, SubnetNoTargetCommitment, CommitmentAlreadyInitialized, ValidatorAlreadyClaimed, NotGateway, NotOwner} from "../errors/IPCErrors.sol";
-import {ValidatorSummary, BatchClaimProofs} from "./Activity.sol";
-import {IValidatorRewarder, IValidatorRewardSetup} from "./IValidatorRewarder.sol";
 import {SubnetIDHelper} from "../lib/SubnetIDHelper.sol";
 import {SubnetID} from "../structs/Subnet.sol";
-import {LibActivityMerkleVerifier} from "./LibActivityMerkleVerifier.sol";
-import {LibDiamond} from "../lib/LibDiamond.sol";
 
 /// The validator reward facet for the parent subnet, i.e. for validators in the child subnet
 /// to claim their reward in the parent subnet, which should be the current subnet this facet
 /// is deployed.
 contract ValidatorRewardFacet is ReentrancyGuard, Pausable {
-    function batchClaim(BatchClaimProofs[] calldata payload) external nonReentrant whenNotPaused {
-        uint256 len = payload.length;
+    function batchSubnetClaim(
+        SubnetID calldata subnet,
+        uint64[] calldata checkpointHeights,
+        Consensus.ValidatorClaim[] calldata claims
+    ) external nonReentrant whenNotPaused {
+        require(checkpointHeights.length == claims.length, "length mismatch");
+        uint256 len = claims.length;
         for (uint256 i = 0; i < len; ) {
-            _batchClaimInSubnet(payload[i]);
+            _claim(subnet, checkpointHeights[i], claims[i].data, claims[i].proof);
             unchecked {
                 i++;
             }
@@ -30,51 +35,41 @@ contract ValidatorRewardFacet is ReentrancyGuard, Pausable {
 
     /// Validators claim their reward for doing work in the child subnet
     function claim(
-        SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        SubnetID calldata subnet,
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata data,
+        Consensus.MerkleHash[] calldata proof
     ) external nonReentrant whenNotPaused {
-        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
-        _claim(s, subnetId, summary, proof);
+        _claim(subnet, checkpointHeight, data, proof);
     }
 
     // ======== Internal functions ===========
 
     function handleRelay() internal pure {
-        // no opt for now
+        // no-op for now
         return;
     }
 
-    function _batchClaimInSubnet(BatchClaimProofs calldata payload) internal {
-        uint256 len = payload.proofs.length;
-        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
-
-        for (uint256 i = 0; i < len; ) {
-            _claim(s, payload.subnetId, payload.proofs[i].summary, payload.proofs[i].proof);
-            unchecked {
-                i++;
-            }
-        }
-    }
-
     function _claim(
-        ValidatorRewardStorage storage s, 
         SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal {
+        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
+
         // note: No need to check if the subnet is active. If the subnet is not active, the checkpointHeight
         // note: will never exist.
 
-        if (msg.sender != summary.validator) {
+        if (msg.sender != detail.validator) {
             revert NotValidator(msg.sender);
         }
 
         if (s.validatorRewarder == address(0)) {
             return handleRelay();
         }
 
-        LibValidatorReward.handleDistribution(s, subnetId, summary, proof);
+        LibValidatorReward.handleDistribution(subnetId, checkpointHeight, detail, proof);
     }
 }
 
@@ -102,7 +97,7 @@ struct ValidatorRewardStorage {
 }
 
 /// The payload for list commitments query
-struct ListCommimentDetail {
+struct ListCommitmentDetail {
     /// The child subnet checkpoint height
     uint64 checkpointHeight;
     /// The actual commiment of the activities
@@ -121,7 +116,7 @@ library LibValidatorReward {
     function initNewDistribution(
         SubnetID calldata subnetId,
         uint64 checkpointHeight,
-        bytes32 commitment,
+        Consensus.MerkleHash commitment,
         uint64 totalActiveValidators
     ) internal {
         ValidatorRewardStorage storage ds = facetStorage();
@@ -132,24 +127,24 @@ library LibValidatorReward {
             revert CommitmentAlreadyInitialized();
         }
 
-        ds.commitments[subnetKey].set(bytes32(uint256(checkpointHeight)), commitment);
+        ds.commitments[subnetKey].set(bytes32(uint256(checkpointHeight)), Consensus.MerkleHash.unwrap(commitment));
         ds.distributions[subnetKey][checkpointHeight].totalValidators = totalActiveValidators;
     }
 
     function listCommitments(
         SubnetID calldata subnetId
-    ) internal view returns (ListCommimentDetail[] memory listDetails) {
+    ) internal view returns (ListCommitmentDetail[] memory listDetails) {
         ValidatorRewardStorage storage ds = facetStorage();
 
         bytes32 subnetKey = subnetId.toHash();
 
         uint256 size = ds.commitments[subnetKey].length();
-        listDetails = new ListCommimentDetail[](size);
+        listDetails = new ListCommitmentDetail[](size);
 
         for (uint256 i = 0; i < size; ) {
             (bytes32 heightBytes32, bytes32 commitment) = ds.commitments[subnetKey].at(i);
 
-            listDetails[i] = ListCommimentDetail({
+            listDetails[i] = ListCommitmentDetail({
                 checkpointHeight: uint64(uint256(heightBytes32)),
                 commitment: commitment
             });
@@ -178,18 +173,20 @@ library LibValidatorReward {
     }
 
     function handleDistribution(
-        ValidatorRewardStorage storage s,
         SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal {
+        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
+
         bytes32 subnetKey = subnetId.toHash();
 
-        bytes32 commitment = ensureValidCommitment(s, subnetKey, summary.checkpointHeight);
-        LibActivityMerkleVerifier.ensureValidProof(commitment, summary, proof);
+        bytes32 commitment = ensureValidCommitment(s, subnetKey, checkpointHeight);
+        LibActivityMerkleVerifier.ensureValidProof(commitment, detail, proof);
 
-        validatorTryClaim(s, subnetKey, summary.checkpointHeight, summary.validator);
-        IValidatorRewarder(s.validatorRewarder).disburseRewards(subnetId, summary);
+        validatorTryClaim(s, subnetKey, checkpointHeight, detail.validator);
+        IValidatorRewarder(s.validatorRewarder).disburseRewards(subnetId, detail);
     }
 
     function ensureValidCommitment(