// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @title RoleManager
 * @notice Generic role manager to manage slashing and cooldown admin in StakedAaveV3.
 *         It implements a claim admin role pattern to safely migrate between different admin addresses
 * @author Aave
 **/
contract RoleManager {
  struct InitAdmin {
    uint256 role;
    address admin;
  }

  mapping(uint256 => address) private _admins;
  mapping(uint256 => address) private _pendingAdmins;

  event PendingAdminChanged(address indexed newPendingAdmin, uint256 role);
  event RoleClaimed(address indexed newAdmin, uint256 role);

  modifier onlyRoleAdmin(uint256 role) {
    require(_admins[role] == msg.sender, 'CALLER_NOT_ROLE_ADMIN');
    _;
  }

  modifier onlyPendingRoleAdmin(uint256 role) {
    require(
      _pendingAdmins[role] == msg.sender,
      'CALLER_NOT_PENDING_ROLE_ADMIN'
    );
    _;
  }

  /**
   * @dev returns the admin associated with the specific role
   * @param role the role associated with the admin being returned
   **/
  function getAdmin(uint256 role) public view returns (address) {
    return _admins[role];
  }

  /**
   * @dev returns the pending admin associated with the specific role
   * @param role the role associated with the pending admin being returned
   **/
  function getPendingAdmin(uint256 role) public view returns (address) {
    return _pendingAdmins[role];
  }

  /**
   * @dev sets the pending admin for a specific role
   * @param role the role associated with the new pending admin being set
   * @param newPendingAdmin the address of the new pending admin
   **/
  function setPendingAdmin(uint256 role, address newPendingAdmin)
    public
    onlyRoleAdmin(role)
  {
    _pendingAdmins[role] = newPendingAdmin;
    emit PendingAdminChanged(newPendingAdmin, role);
  }

  /**
   * @dev allows the caller to become a specific role admin
   * @param role the role associated with the admin claiming the new role
   **/
  function claimRoleAdmin(uint256 role) external onlyPendingRoleAdmin(role) {
    _admins[role] = msg.sender;
    _pendingAdmins[role] = address(0);
    emit RoleClaimed(msg.sender, role);
  }

  function _initAdmins(InitAdmin[] memory initAdmins) internal {
    for (uint256 i = 0; i < initAdmins.length; i++) {
      require(
        _admins[initAdmins[i].role] == address(0) &&
          initAdmins[i].admin != address(0),
        'ADMIN_CANNOT_BE_INITIALIZED'
      );
      _admins[initAdmins[i].role] = initAdmins[i].admin;
      emit RoleClaimed(initAdmins[i].admin, initAdmins[i].role);
    }
  }
}