Adding interface for applications that use operator role and delay in…

… authorization decrease

contracts/staking/IApplicationWithDecreaseDelay.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// ██████████████     ▐████▌     ██████████████
+// ██████████████     ▐████▌     ██████████████
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+// ██████████████     ▐████▌     ██████████████
+// ██████████████     ▐████▌     ██████████████
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+
+pragma solidity ^0.8.9;
+
+import "./IApplication.sol";
+
+/// @title  Interface for Threshold Network applications with delay after decrease request
+interface IApplicationWithDecreaseDelay is IApplication {
+    /// @notice Returns authorization-related parameters of the application.
+    /// @dev The minimum authorization is also returned by `minimumAuthorization()`
+    ///      function, as a requirement of `IApplication` interface.
+    /// @return minimumAuthorization The minimum authorization amount required
+    ///         so that operator can participate in the application.
+    /// @return authorizationDecreaseDelay Delay in seconds that needs to pass
+    ///         between the time authorization decrease is requested and the
+    ///         time that request gets approved. Protects against free-riders
+    ///         earning rewards and not being active in the network.
+    /// @return authorizationDecreaseChangePeriod Authorization decrease change
+    ///        period in seconds. It is the time, before authorization decrease
+    ///        delay end, during which the pending authorization decrease
+    ///        request can be overwritten.
+    ///        If set to 0, pending authorization decrease request can not be
+    ///        overwritten until the entire `authorizationDecreaseDelay` ends.
+    ///        If set to value equal `authorizationDecreaseDelay`, request can
+    ///        always be overwritten.
+    function authorizationParameters()
+        external
+        view
+        returns (
+            uint96 minimumAuthorization,
+            uint64 authorizationDecreaseDelay,
+            uint64 authorizationDecreaseChangePeriod
+        );
+
+    /// @notice Returns the amount of stake that is pending authorization
+    ///         decrease for the given staking provider. If no authorization
+    ///         decrease has been requested, returns zero.
+    function pendingAuthorizationDecrease(address _stakingProvider)
+        external
+        view
+        returns (uint96);
+
+    /// @notice Returns the remaining time in seconds that needs to pass before
+    ///         the requested authorization decrease can be approved.
+    function remainingAuthorizationDecreaseDelay(address stakingProvider)
+        external
+        view
+        returns (uint64);
+
+    /// @notice Approves the previously registered authorization decrease
+    ///         request. Reverts if authorization decrease delay has not passed
+    ///         yet or if the authorization decrease was not requested for the
+    ///         given staking provider.
+    function approveAuthorizationDecrease(address stakingProvider) external;
+}

contracts/staking/IApplicationWithOperator.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// ██████████████     ▐████▌     ██████████████
+// ██████████████     ▐████▌     ██████████████
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+// ██████████████     ▐████▌     ██████████████
+// ██████████████     ▐████▌     ██████████████
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+//               ▐████▌    ▐████▌
+
+pragma solidity ^0.8.9;
+
+import "./IApplication.sol";
+
+/// @title  Interface for Threshold Network applications with operator role
+interface IApplicationWithOperator is IApplication {
+    /// @notice Returns operator registered for the given staking provider.
+    function stakingProviderToOperator(address stakingProvider)
+        external
+        view
+        returns (address);
+
+    /// @notice Used by staking provider to set operator address that will
+    ///         operate a node. The operator addressmust be unique.
+    ///         Reverts if the operator is already set for the staking provider
+    ///         or if the operator address is already in use.
+    /// @dev    Depending on application the given staking provider can set operator
+    ///         address only one or multiple times. Besides that application can decide
+    ///         if function reverts if there is a pending authorization decrease for
+    ///         the staking provider.
+    function registerOperator(address operator) external;
+
+    // TODO consider that?
+    // /// @notice Used by additional role (owner for example) to set operator address that will
+    // ///         operate a node for the specified staking provider.
+    // function registerOperator(address stakingProvider, address operator) external;
+}