// SPDX-License-Identifier: LGPL-3.0-only

/// @title Zodiac Avatar - A contract that manages modules that can execute transactions via this contract.
pragma solidity >=0.7.0 <0.9.0;

import {Enum} from "@gnosis.pm/safe-contracts/contracts/common/Enum.sol";

interface IAvatar {
  event EnabledModule(address module);
  event DisabledModule(address module);
  event ExecutionFromModuleSuccess(address indexed module);
  event ExecutionFromModuleFailure(address indexed module);

  /// @dev Enables a module on the avatar.
  /// @notice Can only be called by the avatar.
  /// @notice Modules should be stored as a linked list.
  /// @notice Must emit EnabledModule(address module) if successful.
  /// @param module Module to be enabled.
  function enableModule(address module) external;

  /// @dev Disables a module on the avatar.
  /// @notice Can only be called by the avatar.
  /// @notice Must emit DisabledModule(address module) if successful.
  /// @param prevModule Address that pointed to the module to be removed in the linked list
  /// @param module Module to be removed.
  function disableModule(address prevModule, address module) external;

  /// @dev Allows a Module to execute a transaction.
  /// @notice Can only be called by an enabled module.
  /// @notice Must emit ExecutionFromModuleSuccess(address module) if successful.
  /// @notice Must emit ExecutionFromModuleFailure(address module) if unsuccessful.
  /// @param to Destination address of module transaction.
  /// @param value Ether value of module transaction.
  /// @param data Data payload of module transaction.
  /// @param operation Operation type of module transaction: 0 == call, 1 == delegate call.
  function execTransactionFromModule(
    address to,
    uint256 value,
    bytes memory data,
    Enum.Operation operation
  ) external returns (bool success);

  /// @dev Allows a Module to execute a transaction and return data
  /// @notice Can only be called by an enabled module.
  /// @notice Must emit ExecutionFromModuleSuccess(address module) if successful.
  /// @notice Must emit ExecutionFromModuleFailure(address module) if unsuccessful.
  /// @param to Destination address of module transaction.
  /// @param value Ether value of module transaction.
  /// @param data Data payload of module transaction.
  /// @param operation Operation type of module transaction: 0 == call, 1 == delegate call.
  function execTransactionFromModuleReturnData(
    address to,
    uint256 value,
    bytes memory data,
    Enum.Operation operation
  ) external returns (bool success, bytes memory returnData);

  /// @dev Returns if an module is enabled
  /// @return True if the module is enabled
  function isModuleEnabled(address module) external view returns (bool);

  /// @dev Returns array of modules.
  /// @param start Start of the page.
  /// @param pageSize Maximum number of modules that should be returned.
  /// @return array Array of modules.
  /// @return next Start of the next page.
  function getModulesPaginated(
    address start,
    uint256 pageSize
  ) external view returns (address[] memory array, address next);
}