// SPDX-License-Identifier: MIT
pragma solidity ^0.8.29;

/// @title IL2Registrar
/// @notice Interface for the L2 subdomain registrar
/// @dev Handles subdomain registration with label validation for Towns domains.
///      Only Towns smart accounts (IModularAccount) can register domains.
///      First registration per account is free, subsequent registrations are charged via FeeManager.
interface IL2Registrar {
    /// @notice Registers a new subdomain
    /// @dev Only callable by Towns smart accounts (IModularAccount).
    ///      First registration is free, subsequent ones are charged via FeeManager.
    /// @param label The subdomain label to register (e.g., "alice" for "alice.towns.eth")
    /// @param owner The address that will own the subdomain NFT
    function register(string calldata label, address owner) external;

    /// @notice Sets the space factory address (owner only)
    /// @param spaceFactory The new space factory address
    function setSpaceFactory(address spaceFactory) external;

    /// @notice Sets the registry address (owner only)
    /// @param registry The new registry address
    function setRegistry(address registry) external;

    /// @notice Sets the currency (owner only)
    /// @param currency The new currency
    function setCurrency(address currency) external;

    /// @notice Checks if a label is available for registration
    /// @dev Returns false if label is invalid OR already registered
    /// @param label The subdomain label to check (e.g., "alice")
    /// @return True if the label can be registered, false otherwise
    function isAvailable(string calldata label) external view returns (bool);

    /// @notice Returns the registry address this registrar points to
    /// @return The address of the L2Registry diamond contract
    function getRegistry() external view returns (address);

    /// @notice Returns the coinType used for address resolution
    /// @dev Computed as 0x80000000 | chainId per ENSIP-11
    /// @return The ENSIP-11 compliant coinType for this chain
    function getCoinType() external view returns (uint256);

    /// @notice Returns the space factory address
    /// @return The address of the SpaceFactory diamond contract
    function getSpaceFactory() external view returns (address);

    /// @notice Returns the currency used for registration fees
    /// @return The currency used for registration fees
    function getCurrency() external view returns (address);

    /// @notice Checks if a label format is valid (without checking availability)
    /// @dev Validates: length (3-63), allowed chars (a-z, 0-9, hyphen), no leading/trailing hyphen
    /// @param label The subdomain label to validate
    /// @return True if the label format is valid
    function isValidLabel(string calldata label) external pure returns (bool);
}