pragma solidity >=0.8.4;

import "./ENS.sol";
import "./ENSRegistry.sol";

/// The ENS registry contract.
contract ENSRegistryWithFallback is ENSRegistry {
    ENS public old;

    /// @dev Constructs a new ENS registrar.
    constructor(ENS _old) public ENSRegistry() {
        old = _old;
    }

    /// @dev Returns the address of the resolver for the specified node.
    /// @param node The specified node.
    /// @return address of the resolver.
    function resolver(bytes32 node) public view override returns (address) {
        if (!recordExists(node)) {
            return old.resolver(node);
        }

        return super.resolver(node);
    }

    /// @dev Returns the address that owns the specified node.
    /// @param node The specified node.
    /// @return address of the owner.
    function owner(bytes32 node) public view override returns (address) {
        if (!recordExists(node)) {
            return old.owner(node);
        }

        return super.owner(node);
    }

    /// @dev Returns the TTL of a node, and any records associated with it.
    /// @param node The specified node.
    /// @return ttl of the node.
    function ttl(bytes32 node) public view override returns (uint64) {
        if (!recordExists(node)) {
            return old.ttl(node);
        }

        return super.ttl(node);
    }

    function _setOwner(bytes32 node, address owner) internal override {
        address addr = owner;
        if (addr == address(0x0)) {
            addr = address(this);
        }

        super._setOwner(node, addr);
    }
}