// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

interface IProtocolConfigManager {
    /**
     * @dev Emitted when address of collector for Protocol's external fees is changed.
     * @param oldCollector Address of old collector.
     * @param newCollector Address of new collector.
     */
    event ProtocolExternalFeesCollectorChanged(address oldCollector, address newCollector);

    /**
     * @dev Changes the address of collector for Protocol's external fees.
     * Also emits `ProtocolExternalFeesCollectorChanged`.
     * @param newProtocolExternalFeesCollector The new collector's address.
     */
    function changeProtocolExternalFeesCollector(address newProtocolExternalFeesCollector) external;

    /**
     * @dev Returns the base token that's used for stable price denomination.
     * @return The base token address.
     */
    function baseToken() external view returns (address);

    /**
     * @dev Returns the base token decimals.
     * @return The base token decimals.
     */
    function baseTokenDecimals() external view returns (uint8);

    /**
     * @dev Returns address of Protocol's external fees collector.
     * @return The address of Protocol's external fees collector.
     */
    function protocolExternalFeesCollector() external view returns (address);
}