[WIP] Horizon Staking

packages/contracts/contracts/base/IMulticall.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 pragma abicoder v2;
 
 /**

packages/contracts/contracts/base/Multicall.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity ^0.7.6 || 0.8.24;
 pragma abicoder v2;
 
 import "./IMulticall.sol";

packages/contracts/contracts/curation/ICuration.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 /**
  * @title Curation Interface

packages/contracts/contracts/epochs/IEpochManager.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 interface IEpochManager {
     // -- Configuration --

packages/contracts/contracts/gateway/ICallhookReceiver.sol

@@ -6,7 +6,7 @@
  * be allowlisted by the governor, but also implement this interface that contains
  * the function that will actually be called by the L2GraphTokenGateway.
  */
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 interface ICallhookReceiver {
     /**

packages/contracts/contracts/governance/IController.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity >=0.6.12 <0.8.0;
+pragma solidity >=0.6.12 <0.9.0;
 
 interface IController {
     function getGovernor() external view returns (address);

packages/contracts/contracts/governance/IManaged.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 import { IController } from "./IController.sol";
 

packages/contracts/contracts/l2/staking/IL2Staking.sol

@@ -5,6 +5,7 @@ pragma abicoder v2;
 
 import { IStaking } from "../../staking/IStaking.sol";
 import { IL2StakingBase } from "./IL2StakingBase.sol";
+import { IL2StakingTypes } from "./IL2StakingTypes.sol";
 
 /**
  * @title Interface for the L2 Staking contract
@@ -15,21 +16,4 @@ import { IL2StakingBase } from "./IL2StakingBase.sol";
  * the custom setup of the Staking contract where part of the functionality is implemented
  * in a separate contract (StakingExtension) to which calls are delegated through the fallback function.
  */
-interface IL2Staking is IStaking, IL2StakingBase {
-    /// @dev Message codes for the L1 -> L2 bridge callhook
-    enum L1MessageCodes {
-        RECEIVE_INDEXER_STAKE_CODE,
-        RECEIVE_DELEGATION_CODE
-    }
-
-    /// @dev Encoded message struct when receiving indexer stake through the bridge
-    struct ReceiveIndexerStakeData {
-        address indexer;
-    }
-
-    /// @dev Encoded message struct when receiving delegation through the bridge
-    struct ReceiveDelegationData {
-        address indexer;
-        address delegator;
-    }
-}
+interface IL2Staking is IStaking, IL2StakingBase, IL2StakingTypes {}

packages/contracts/contracts/l2/staking/IL2StakingBase.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 import { ICallhookReceiver } from "../../gateway/ICallhookReceiver.sol";
 

packages/contracts/contracts/l2/staking/IL2StakingTypes.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+pragma solidity >=0.6.12 <0.9.0;
+
+interface IL2StakingTypes {
+    /// @dev Message codes for the L1 -> L2 bridge callhook
+    enum L1MessageCodes {
+        RECEIVE_INDEXER_STAKE_CODE,
+        RECEIVE_DELEGATION_CODE
+    }
+
+    /// @dev Encoded message struct when receiving indexer stake through the bridge
+    struct ReceiveIndexerStakeData {
+        address indexer;
+    }
+
+    /// @dev Encoded message struct when receiving delegation through the bridge
+    struct ReceiveDelegationData {
+        address indexer;
+        address delegator;
+    }
+}

packages/contracts/contracts/l2/staking/L2Staking.sol

@@ -8,6 +8,7 @@ import { Staking } from "../../staking/Staking.sol";
 import { IL2StakingBase } from "./IL2StakingBase.sol";
 import { IL2Staking } from "./IL2Staking.sol";
 import { Stakes } from "../../staking/libs/Stakes.sol";
+import { IL2StakingTypes } from "./IL2StakingTypes.sol";
 
 /**
  * @title L2Staking contract
@@ -63,16 +64,16 @@ contract L2Staking is Staking, IL2StakingBase {
         require(_from == counterpartStakingAddress, "ONLY_L1_STAKING_THROUGH_BRIDGE");
         (uint8 code, bytes memory functionData) = abi.decode(_data, (uint8, bytes));
 
-        if (code == uint8(IL2Staking.L1MessageCodes.RECEIVE_INDEXER_STAKE_CODE)) {
-            IL2Staking.ReceiveIndexerStakeData memory indexerData = abi.decode(
+        if (code == uint8(IL2StakingTypes.L1MessageCodes.RECEIVE_INDEXER_STAKE_CODE)) {
+            IL2StakingTypes.ReceiveIndexerStakeData memory indexerData = abi.decode(
                 functionData,
-                (IL2Staking.ReceiveIndexerStakeData)
+                (IL2StakingTypes.ReceiveIndexerStakeData)
             );
             _receiveIndexerStake(_amount, indexerData);
-        } else if (code == uint8(IL2Staking.L1MessageCodes.RECEIVE_DELEGATION_CODE)) {
-            IL2Staking.ReceiveDelegationData memory delegationData = abi.decode(
+        } else if (code == uint8(IL2StakingTypes.L1MessageCodes.RECEIVE_DELEGATION_CODE)) {
+            IL2StakingTypes.ReceiveDelegationData memory delegationData = abi.decode(
                 functionData,
-                (IL2Staking.ReceiveDelegationData)
+                (IL2StakingTypes.ReceiveDelegationData)
             );
             _receiveDelegation(_amount, delegationData);
         } else {
@@ -87,7 +88,10 @@ contract L2Staking is Staking, IL2StakingBase {
      * @param _amount Amount of tokens that were transferred
      * @param _indexerData struct containing the indexer's address
      */
-    function _receiveIndexerStake(uint256 _amount, IL2Staking.ReceiveIndexerStakeData memory _indexerData) internal {
+    function _receiveIndexerStake(
+        uint256 _amount,
+        IL2StakingTypes.ReceiveIndexerStakeData memory _indexerData
+    ) internal {
         address _indexer = _indexerData.indexer;
         // Deposit tokens into the indexer stake
         __stakes[_indexer].deposit(_amount);
@@ -108,7 +112,10 @@ contract L2Staking is Staking, IL2StakingBase {
      * @param _amount Amount of tokens that were transferred
      * @param _delegationData struct containing the delegator's address and the indexer's address
      */
-    function _receiveDelegation(uint256 _amount, IL2Staking.ReceiveDelegationData memory _delegationData) internal {
+    function _receiveDelegation(
+        uint256 _amount,
+        IL2StakingTypes.ReceiveDelegationData memory _delegationData
+    ) internal {
         // Get the delegation pool of the indexer
         DelegationPool storage pool = __delegationPools[_delegationData.indexer];
         Delegation storage delegation = pool.delegators[_delegationData.delegator];

packages/contracts/contracts/rewards/IRewardsManager.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 interface IRewardsManager {
     /**

packages/contracts/contracts/staking/L1Staking.sol

@@ -9,12 +9,12 @@ import { ITokenGateway } from "../arbitrum/ITokenGateway.sol";
 import { Staking } from "./Staking.sol";
 import { Stakes } from "./libs/Stakes.sol";
 import { IStakingData } from "./IStakingData.sol";
-import { IL2Staking } from "../l2/staking/IL2Staking.sol";
 import { L1StakingV1Storage } from "./L1StakingStorage.sol";
 import { IGraphToken } from "../token/IGraphToken.sol";
 import { IL1StakingBase } from "./IL1StakingBase.sol";
 import { MathUtils } from "./libs/MathUtils.sol";
 import { IL1GraphTokenLockTransferTool } from "./IL1GraphTokenLockTransferTool.sol";
+import { IL2StakingTypes } from "../l2/staking/IL2StakingTypes.sol";
 
 /**
  * @title L1Staking contract
@@ -267,11 +267,11 @@ contract L1Staking is Staking, L1StakingV1Storage, IL1StakingBase {
             );
         }
 
-        IL2Staking.ReceiveIndexerStakeData memory functionData;
+        IL2StakingTypes.ReceiveIndexerStakeData memory functionData;
         functionData.indexer = _l2Beneficiary;
 
         bytes memory extraData = abi.encode(
-            uint8(IL2Staking.L1MessageCodes.RECEIVE_INDEXER_STAKE_CODE),
+            uint8(IL2StakingTypes.L1MessageCodes.RECEIVE_INDEXER_STAKE_CODE),
             abi.encode(functionData)
         );
 
@@ -324,10 +324,13 @@ contract L1Staking is Staking, L1StakingV1Storage, IL1StakingBase {
         delegation.shares = 0;
         bytes memory extraData;
         {
-            IL2Staking.ReceiveDelegationData memory functionData;
+            IL2StakingTypes.ReceiveDelegationData memory functionData;
             functionData.indexer = indexerTransferredToL2[_indexer];
             functionData.delegator = _l2Beneficiary;
-            extraData = abi.encode(uint8(IL2Staking.L1MessageCodes.RECEIVE_DELEGATION_CODE), abi.encode(functionData));
+            extraData = abi.encode(
+                uint8(IL2StakingTypes.L1MessageCodes.RECEIVE_DELEGATION_CODE),
+                abi.encode(functionData)
+            );
         }
 
         _sendTokensAndMessageToL2Staking(

packages/contracts/contracts/upgrades/GraphUpgradeable.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity ^0.7.6 || 0.8.24;
 
 import { IGraphProxy } from "./IGraphProxy.sol";
 

packages/contracts/contracts/upgrades/IGraphProxy.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-pragma solidity ^0.7.6;
+pragma solidity >=0.6.12 <0.9.0;
 
 interface IGraphProxy {
     function admin() external returns (address);