// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.6.11;

// ============ Internal Imports ============
import {IUpdaterManager} from "../interfaces/IUpdaterManager.sol";
import {Home} from "./Home.sol";
// ============ External Imports ============
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {Address} from "@openzeppelin/contracts/utils/Address.sol";

/**
 * @title UpdaterManager
 * @author Celo Labs Inc.
 * @notice MVP / centralized version of contract
 * that will manage Updater bonding, slashing,
 * selection and rotation
 */
contract UpdaterManager is IUpdaterManager, Ownable {
    // ============ Internal Storage ============

    // address of home contract
    address internal home;

    // ============ Private Storage ============

    // address of the current updater
    address private _updater;

    // ============ Events ============

    /**
     * @notice Emitted when a new home is set
     * @param home The address of the new home contract
     */
    event NewHome(address home);

    /**
     * @notice Emitted when slashUpdater is called
     */
    event FakeSlashed(address reporter);

    // ============ Modifiers ============

    /**
     * @notice Require that the function is called
     * by the Home contract
     */
    modifier onlyHome() {
        require(msg.sender == home, "!home");
        _;
    }

    // ============ Constructor ============

    constructor(address _updaterAddress) payable Ownable() {
        _updater = _updaterAddress;
    }

    // ============ External Functions ============

    /**
     * @notice Set the address of the a new home contract
     * @dev only callable by trusted owner
     * @param _home The address of the new home contract
     */
    function setHome(address _home) external onlyOwner {
        require(Address.isContract(_home), "!contract home");
        home = _home;

        emit NewHome(_home);
    }

    /**
     * @notice Set the address of a new updater
     * @dev only callable by trusted owner
     * @param _updaterAddress The address of the new updater
     */
    function setUpdater(address _updaterAddress) external onlyOwner {
        _updater = _updaterAddress;
        Home(home).setUpdater(_updaterAddress);
    }

    /**
     * @notice Slashes the updater
     * @dev Currently does nothing, functionality will be implemented later
     * when updater bonding and rotation are also implemented
     * @param _reporter The address of the entity that reported the updater fraud
     */
    function slashUpdater(address payable _reporter)
        external
        override
        onlyHome
    {
        emit FakeSlashed(_reporter);
    }

    /**
     * @notice Get address of current updater
     * @return the updater address
     */
    function updater() external view override returns (address) {
        return _updater;
    }
}