feat: first implementation of the service staking

.gitleaksignore

@@ -41,3 +41,4 @@ d780294b8dccf047391a71b75dade50a6b89003b:scripts/deployment/l2/globals_gnosis_ch
 7d2fbdb1556dc3ed289edf7e116b378b6f6a9d83:scripts/deployment/l2/bridges/gnosis/test_service_registry_token_utility_change_drainer.js:generic-api-key:44
 7bb76e80382eff3c538af340289ed8241f4e4551:scripts/deployment/l2/globals_gnosis_mainnet.json:generic-api-key:1
 7bb76e80382eff3c538af340289ed8241f4e4551:scripts/deployment/l2/globals_gnosis_mainnet.json:generic-api-key:2
+233a57ccda8d5d84a86133422daa99807801d9fc:scripts/deployment/l2/globals_gnosis_mainnet.json:generic-api-key:2

contracts/interfaces/IToken.sol

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.21;
+
+/// @dev Generic token interface for IERC20 and IERC721 tokens.
+interface IToken {
+    /// @dev Gets the amount of tokens owned by a specified account.
+    /// @param account Account address.
+    /// @return Amount of tokens owned.
+    function balanceOf(address account) external view returns (uint256);
+
+    /// @dev Gets the owner of the token Id.
+    /// @param tokenId Token Id.
+    /// @return Token Id owner address.
+    function ownerOf(uint256 tokenId) external view returns (address);
+
+    /// @dev Gets the total amount of tokens stored by the contract.
+    /// @return Amount of tokens.
+    function totalSupply() external view returns (uint256);
+
+    /// @dev Transfers the token amount.
+    /// @param to Address to transfer to.
+    /// @param amount The amount to transfer.
+    /// @return True if the function execution is successful.
+    function transfer(address to, uint256 amount) external returns (bool);
+
+    /// @dev Gets remaining number of tokens that the `spender` can transfer on behalf of `owner`.
+    /// @param owner Token owner.
+    /// @param spender Account address that is able to transfer tokens on behalf of the owner.
+    /// @return Token amount allowed to be transferred.
+    function allowance(address owner, address spender) external view returns (uint256);
+
+    /// @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
+    /// @param spender Account address that will be able to transfer tokens on behalf of the caller.
+    /// @param amount Token amount.
+    /// @return True if the function execution is successful.
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    /// @dev Transfers the token amount that was previously approved up until the maximum allowance.
+    /// @param from Account address to transfer from.
+    /// @param to Account address to transfer to.
+    /// @param amount Amount to transfer to.
+    /// @return True if the function execution is successful.
+    function transferFrom(address from, address to, uint256 amount) external returns (bool);
+
+    /// @dev Gets the number of token decimals.
+    /// @return Number of token decimals.
+    function decimals() external view returns (uint8);
+}

contracts/staking/ServiceStaking.sol

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.21;
+
+import {ServiceStakingBase} from "./ServiceStakingBase.sol";
+
+/// @title ServiceStakingToken - Smart contract for staking a service by its owner when the service has an ETH as the deposit
+/// @author Aleksandr Kuperman - <[email protected]>
+/// @author Andrey Lebedev - <[email protected]>
+/// @author Mariapia Moscatiello - <[email protected]>
+contract ServiceStaking is ServiceStakingBase {
+    /// @dev ServiceStaking constructor.
+    /// @param _maxNumServices Maximum number of staking services.
+    /// @param _rewardsPerSecond Staking rewards per second (in single digits).
+    /// @param _minStakingDeposit Minimum staking deposit for a service to be eligible to stake.
+    /// @param _livenessRatio Liveness ratio: number of nonces per second (in 18 digits).
+    /// @param _serviceRegistry ServiceRegistry contract address.
+    constructor(
+        uint256 _maxNumServices,
+        uint256 _rewardsPerSecond,
+        uint256 _minStakingDeposit,
+        uint256 _livenessRatio,
+        address _serviceRegistry
+    )
+      ServiceStakingBase(_maxNumServices, _rewardsPerSecond, _minStakingDeposit, _livenessRatio, _serviceRegistry)
+    {}
+
+    /// @dev Withdraws the reward amount to a service owner.
+    /// @param to Address to.
+    /// @param amount Amount to withdraw.
+    function _withdraw(address to, uint256 amount) internal override {
+        // Update the contract balance
+        balance -= amount;
+
+        // Transfer the amount
+        (bool result, ) = to.call{value: amount}("");
+        if (!result) {
+            revert TransferFailed(address(0), address(this), to, amount);
+        }
+    }
+
+    receive() external payable {
+        // Add to the contract and available rewards balances
+        uint256 newBalance = balance + msg.value;
+        uint256 newAvailableRewards = availableRewards + msg.value;
+
+        // Record the new actual balance and available rewards
+        balance = newBalance;
+        availableRewards = newAvailableRewards;
+
+        emit Deposit(msg.sender, msg.value, newBalance, newAvailableRewards);
+    }
+}