feat(DisputeKit): add flushing feature

contracts/src/arbitration/KlerosCoreBase.sol

@@ -101,6 +101,7 @@ abstract contract KlerosCoreBase is IArbitratorV2 {
     Court[] public courts; // The courts.
     IDisputeKit[] public disputeKits; // Array of dispute kits.
     Dispute[] public disputes; // The disputes.
+    mapping(IDisputeKit => uint256) public disputeKitIDs; // Maps dispute kit's address to its index.
     mapping(IERC20 => CurrencyRate) public currencyRates; // The price of each token in ETH.
     bool public paused; // Whether asset withdrawals are paused.
 
@@ -216,6 +217,7 @@ abstract contract KlerosCoreBase is IArbitratorV2 {
 
         // DISPUTE_KIT_CLASSIC
         disputeKits.push(_disputeKit);
+        disputeKitIDs[_disputeKit] = DISPUTE_KIT_CLASSIC;
 
         emit DisputeKitCreated(DISPUTE_KIT_CLASSIC, _disputeKit);
 
@@ -316,6 +318,7 @@ abstract contract KlerosCoreBase is IArbitratorV2 {
     function addNewDisputeKit(IDisputeKit _disputeKitAddress) external onlyByGovernor {
         uint256 disputeKitID = disputeKits.length;
         disputeKits.push(_disputeKitAddress);
+        disputeKitIDs[_disputeKitAddress] = disputeKitID;
         emit DisputeKitCreated(disputeKitID, _disputeKitAddress);
     }
 
@@ -468,18 +471,19 @@ abstract contract KlerosCoreBase is IArbitratorV2 {
         _setStake(msg.sender, _courtID, _newStake, false, OnError.Revert);
     }
 
-    /// @dev Sets the stake of a specified account in a court, typically to apply a delayed stake or unstake inactive jurors.
+    /// @dev Sets the stake of a specified account in a court, typically to apply a delayed stake or unstake inactive/ineligible jurors.
     /// @param _account The account whose stake is being set.
     /// @param _courtID The ID of the court.
     /// @param _newStake The new stake.
     /// @param _alreadyTransferred Whether the PNKs have already been transferred to the contract.
-    function setStakeBySortitionModule(
+    function setStakeBySortitionModuleOrDK(
         address _account,
         uint96 _courtID,
         uint256 _newStake,
         bool _alreadyTransferred
     ) external {
-        if (msg.sender != address(sortitionModule)) revert SortitionModuleOnly();
+        if (msg.sender != address(sortitionModule) && disputeKitIDs[IDisputeKit(msg.sender)] == 0)
+            revert SortitionModuleOrDKOnly();
         _setStake(_account, _courtID, _newStake, _alreadyTransferred, OnError.Return);
     }
 
@@ -1144,7 +1148,7 @@ abstract contract KlerosCoreBase is IArbitratorV2 {
     error GovernorOnly();
     error GuardianOrGovernorOnly();
     error DisputeKitOnly();
-    error SortitionModuleOnly();
+    error SortitionModuleOrDKOnly();
     error UnsuccessfulCall();
     error InvalidDisputKitParent();
     error DepthLevelMax();

contracts/src/arbitration/SortitionModuleBase.sol

@@ -206,7 +206,7 @@ abstract contract SortitionModuleBase is ISortitionModule {
             DelayedStake storage delayedStake = delayedStakes[i];
             // Delayed stake could've been manually removed already. In this case simply move on to the next item.
             if (delayedStake.account != address(0)) {
-                core.setStakeBySortitionModule(
+                core.setStakeBySortitionModuleOrDK(
                     delayedStake.account,
                     delayedStake.courtID,
                     delayedStake.stake,
@@ -433,7 +433,7 @@ abstract contract SortitionModuleBase is ISortitionModule {
     function setJurorInactive(address _account) external override onlyByCore {
         uint96[] memory courtIDs = getJurorCourtIDs(_account);
         for (uint256 j = courtIDs.length; j > 0; j--) {
-            core.setStakeBySortitionModule(_account, courtIDs[j - 1], 0, false);
+            core.setStakeBySortitionModuleOrDK(_account, courtIDs[j - 1], 0, false);
         }
     }
 

contracts/src/arbitration/dispute-kits/DisputeKitSybilResistant.sol

@@ -465,6 +465,20 @@ contract DisputeKitSybilResistant is IDisputeKit, Initializable, UUPSProxiable {
         }
     }
 
+    /// @dev Unstakes the jurors who are not eligible for drawing, so they don't interfere with the drawing process.
+    /// Can be called by anyone. The juror will be unstaked if he doesn't pass the check specific to this DK.
+    /// @param _juror The juror to unstake.
+    /// @param _courts The courts to unstake from. Note that each court must support this DK.
+    function flush(address _juror, uint96[] memory _courts) external {
+        require(!_proofOfHumanity(_juror), "The juror is eligible");
+        uint256 disputeKitID = core.disputeKitIDs(this);
+        for (uint256 i = 0; i < _courts.length; i++) {
+            uint96 courtID = _courts[i];
+            require(core.isSupported(courtID, disputeKitID), "DK not supported by court");
+            core.setStakeBySortitionModuleOrDK(_juror, courtID, 0, false);
+        }
+    }
+
     // ************************************* //
     // *           Public Views            * //
     // ************************************* //