Refactor ERC404NullOwnerCappedUpgradeable contract by removing unused interfaces and dependencies

- Deleted the `IERC404` interface and the `DoubleEndedQueue` library, simplifying the contract structure.
- Updated function signatures to remove references to the deleted interface, ensuring compliance with ERC20 and ERC721 standards.
- Streamlined the contract by eliminating unnecessary state variables and constants, enhancing readability and maintainability.
- Adjusted event emissions and error handling to align with the new implementation.

Author: RogerPodacter

contracts/src/ERC404NullOwnerCappedUpgradeable.sol

@@ -3,13 +3,10 @@ pragma solidity 0.8.24;
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
-import {IERC721Receiver} from "@openzeppelin/contracts/interfaces/IERC721Receiver.sol";
 import {ContextUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
 import {IERC20Errors} from "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";
 import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
 import {IERC165} from "@openzeppelin/contracts/interfaces/IERC165.sol";
-import "./interfaces/IERC404.sol";
-import "./lib/DoubleEndedQueue.sol";
 
 /// @title ERC404NullOwnerCappedUpgradeable
 /// @notice Hybrid ERC20/ERC721 implementation with null owner support, supply cap, and upgradeability
@@ -20,11 +17,8 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     IERC165,
     IERC20,
     IERC20Metadata,
-    IERC20Errors,
-    IERC404
+    IERC20Errors
 {
-    using DoubleEndedQueue for DoubleEndedQueue.Uint256Deque;
-
     struct TokenData {
         address owner; // current owner (can be address(0) for null-owner)
         uint88 index; // position in owned[owner] array
@@ -43,44 +37,26 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         uint256 totalSupply;
         uint256 cap;
 
-        // === ERC404 NFT State ===
-        DoubleEndedQueue.Uint256Deque storedERC721Ids;
         mapping(address => uint256[]) owned;
         mapping(uint256 => TokenData) tokens;
         mapping(uint256 => address) getApproved;
         mapping(address => mapping(address => bool)) isApprovedForAll;
-        mapping(address => bool) erc721TransferExempt;
         uint256 minted; // Number of NFTs minted
         uint256 units; // Units for NFT minting (e.g., 1000 * 10^18)
-        uint256 initialChainId;
-        bytes32 initialDomainSeparator;
-        mapping(address => uint256) nonces;
 
         // === Metadata ===
         string name;
         string symbol;
     }
-
-    // =============================================================
-    //                         CONSTANTS
-    // =============================================================
-
-    /// @dev Unique storage slot for EIP-7201 namespaced storage
-    /// keccak256(abi.encode(uint256(keccak256("ethscriptions.storage.ERC404NullOwnerCapped")) - 1)) & ~bytes32(uint256(0xff))
-    bytes32 private constant STORAGE_LOCATION = 0x8a0c9d8e5f7b3a2c1d4e6f8a9b7c5d3e2f1a4b6c8d9e7f5a3b2c1d4e6f8a9b00;
-
+    
     // =============================================================
     //                         EVENTS
     // =============================================================
 
     // ERC20 Events are inherited from IERC20 (Transfer, Approval)
 
     // ERC721 Events (using different names to avoid conflicts with ERC20)
-    // event Transfer(address indexed from, address indexed to, uint256 value);
-    event ERC20Transfer(address indexed from, address indexed to, uint256 value);
     event ERC721Transfer(address indexed from, address indexed to, uint256 indexed id);
-    event ERC721Approval(address indexed owner, address indexed spender, uint256 indexed id);
-    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
 
     // =============================================================
     //                      CUSTOM ERRORS
@@ -91,14 +67,22 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     error ERC20InvalidCap(uint256 cap);
     error InvalidUnits(uint256 units);
     error NotImplemented();
+    error NotFound();
+    error InvalidTokenId();
+    error AlreadyExists();
+    error InvalidRecipient();
+    error Unauthorized();
+    error OwnedIndexOverflow();
 
     // =============================================================
     //                    STORAGE ACCESSOR
     // =============================================================
 
     function _getS() internal pure returns (TokenStorage storage $) {
+        bytes32 slot = keccak256("ethscriptions.storage.ERC404NullOwnerCapped");
+        
         assembly {
-            $.slot := STORAGE_LOCATION
+            $.slot := slot
         }
     }
 
@@ -132,38 +116,36 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         $.symbol = symbol_;
         $.cap = cap_;
         $.units = units_;
-        $.initialChainId = block.chainid;
-        $.initialDomainSeparator = _computeDomainSeparator();
     }
 
     // =============================================================
     //                    ERC20 METADATA VIEWS
     // =============================================================
 
-    function name() public view virtual override(IERC404, IERC20Metadata) returns (string memory) {
+    function name() public view virtual override(IERC20Metadata) returns (string memory) {
         TokenStorage storage $ = _getS();
         return $.name;
     }
 
-    function symbol() public view virtual override(IERC404, IERC20Metadata) returns (string memory) {
+    function symbol() public view virtual override(IERC20Metadata) returns (string memory) {
         TokenStorage storage $ = _getS();
         return $.symbol;
     }
 
-    function decimals() public pure override(IERC404, IERC20Metadata) returns (uint8) {
+    function decimals() public pure override(IERC20Metadata) returns (uint8) {
         return 18;
     }
 
     // =============================================================
     //                     ERC20 VIEWS
     // =============================================================
 
-    function totalSupply() public view virtual override(IERC404, IERC20) returns (uint256) {
+    function totalSupply() public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.totalSupply;
     }
 
-    function balanceOf(address account) public view virtual override(IERC404, IERC20) returns (uint256) {
+    function balanceOf(address account) public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.balances[account];
     }
@@ -179,7 +161,7 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return t.owner == owner_ ? 1 : 0;
     }
 
-    function allowance(address owner, address spender) public view virtual override(IERC404, IERC20) returns (uint256) {
+    function allowance(address owner, address spender) public view virtual override returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.allowances[owner][spender];
     }
@@ -196,17 +178,17 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     //                     ERC721 VIEWS
     // =============================================================
 
-    function erc721TotalSupply() public view virtual override(IERC404) returns (uint256) {
+    function erc721TotalSupply() public view virtual returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.minted;
     }
 
-    function erc721BalanceOf(address owner_) public view virtual override(IERC404) returns (uint256) {
+    function erc721BalanceOf(address owner_) public view virtual returns (uint256) {
         TokenStorage storage $ = _getS();
         return $.owned[owner_].length;
     }
 
-    function ownerOf(uint256 id_) public view virtual override(IERC404) returns (address) {
+    function ownerOf(uint256 id_) public view virtual returns (address) {
         _validateTokenId(id_);
         TokenStorage storage $ = _getS();
         TokenData storage t = $.tokens[id_];
@@ -216,7 +198,7 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return t.owner;
     }
 
-    function owned(address owner_) public view virtual override(IERC404) returns (uint256[] memory) {
+    function owned(address owner_) public view virtual returns (uint256[] memory) {
         TokenStorage storage $ = _getS();
         return $.owned[owner_];
     }
@@ -229,42 +211,11 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return $.getApproved[id_];
     }
 
-    function isApprovedForAll(address owner_, address operator_) public view virtual override(IERC404) returns (bool) {
+    function isApprovedForAll(address owner_, address operator_) public view virtual returns (bool) {
         TokenStorage storage $ = _getS();
         return $.isApprovedForAll[owner_][operator_];
     }
 
-    function erc721TransferExempt(address account_) public view virtual override returns (bool) {
-        TokenStorage storage $ = _getS();
-        return $.erc721TransferExempt[account_];
-    }
-
-    // =============================================================
-    //                       QUEUE VIEWS
-    // =============================================================
-
-    function getERC721QueueLength() public view virtual override returns (uint256) {
-        TokenStorage storage $ = _getS();
-        return $.storedERC721Ids.length();
-    }
-
-    function getERC721TokensInQueue(
-        uint256 start_,
-        uint256 count_
-    ) public view virtual override returns (uint256[] memory) {
-        TokenStorage storage $ = _getS();
-        uint256[] memory tokensInQueue = new uint256[](count_);
-
-        for (uint256 i = start_; i < start_ + count_;) {
-            tokensInQueue[i - start_] = $.storedERC721Ids.at(i);
-            unchecked {
-                ++i;
-            }
-        }
-
-        return tokensInQueue;
-    }
-
     // =============================================================
     //                      OTHER VIEWS
     // =============================================================
@@ -285,57 +236,53 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
     }
 
     /// @notice tokenURI must be implemented by child contract
-    function tokenURI(uint256 id_) public view virtual override(IERC404) returns (string memory);
+    function tokenURI(uint256 id_) public view virtual returns (string memory);
 
     // =============================================================
     //                   ERC20 OPERATIONS
     // =============================================================
 
-    function transfer(address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function transfer(address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function approve(address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function approve(address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function transferFrom(address, address, uint256) public pure virtual override(IERC404, IERC20) returns (bool) {
+    function transferFrom(address, address, uint256) public pure virtual override returns (bool) {
         revert NotImplemented();
     }
 
-    function erc20Approve(address, uint256) public pure virtual override returns (bool) {
+    function erc20Approve(address, uint256) public pure virtual returns (bool) {
         revert NotImplemented();
     }
 
-    function erc20TransferFrom(address, address, uint256) public pure virtual override returns (bool) {
+    function erc20TransferFrom(address, address, uint256) public pure virtual returns (bool) {
         revert NotImplemented();
     }
 
     // =============================================================
     //                   ERC721 OPERATIONS
     // =============================================================
 
-    function erc721Approve(address, uint256) public pure virtual override {
+    function erc721Approve(address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function erc721TransferFrom(address, address, uint256) public pure virtual override {
+    function erc721TransferFrom(address, address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function setApprovalForAll(address, bool) public pure virtual override {
+    function setApprovalForAll(address, bool) public pure virtual {
         revert NotImplemented();
     }
 
-    function safeTransferFrom(address, address, uint256) public pure virtual override {
+    function safeTransferFrom(address, address, uint256) public pure virtual {
         revert NotImplemented();
     }
 
-    function safeTransferFrom(address, address, uint256, bytes memory) public pure virtual override {
-        revert NotImplemented();
-    }
-
-    function setSelfERC721TransferExempt(bool) public pure virtual override {
+    function safeTransferFrom(address, address, uint256, bytes memory) public pure virtual {
         revert NotImplemented();
     }
 
@@ -367,7 +314,6 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         }
 
         emit Transfer(from_, to_, value_);
-        // emit ERC20Transfer(from_, to_, value_);
     }
 
     /// @notice Transfer an ERC721 token
@@ -454,44 +400,6 @@ abstract contract ERC404NullOwnerCappedUpgradeable is
         return
             interfaceId == type(IERC165).interfaceId ||
             interfaceId == type(IERC20).interfaceId ||
-            interfaceId == type(IERC20Metadata).interfaceId ||
-            interfaceId == type(IERC404).interfaceId;
-    }
-    
-  /// @notice Internal function to compute domain separator for EIP-2612 permits
-    function _computeDomainSeparator() internal view virtual returns (bytes32) {
-        return
-        keccak256(
-            abi.encode(
-            keccak256(
-                "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
-            ),
-            keccak256(bytes(name())),
-            keccak256("1"),
-            block.chainid,
-            address(this)
-            )
-        );
-    }
-    
-    function permit(
-        address owner_,
-        address spender_,
-        uint256 value_,
-        uint256 deadline_,
-        uint8 v_,
-        bytes32 r_,
-        bytes32 s_
-    ) public virtual {
-        revert NotImplemented();
-    }
-
-    /// @notice EIP-2612 domain separator
-    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
-        TokenStorage storage $ = _getS();
-        return
-            block.chainid == $.initialChainId
-                ? $.initialDomainSeparator
-                : _computeDomainSeparator();
+            interfaceId == type(IERC20Metadata).interfaceId;
     }
 }