// SPDX-License-Identifier: MIT // Filosofía Código Contracts based on OpenZeppelin pragma solidity ^0.8.0; import "../common/Context.sol"; import "../common/Address.sol"; import "../common/Strings.sol"; import "../common/Ownable.sol"; interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } interface IERC721 is IERC165 { /** * @dev Emitted when `tokenId` token is transferred from `from` to `to`. */ event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token. */ event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets. */ event ApprovalForAll(address indexed owner, address indexed operator, bool approved); /** * @dev Returns the number of tokens in ``owner``'s account. */ function balanceOf(address owner) external view returns (uint256 balance); /** * @dev Returns the owner of the `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function ownerOf(uint256 tokenId) external view returns (address owner); /** * @dev Safely transfers `tokenId` token from `from` to `to`. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external; /** * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients * are aware of the ERC721 protocol to prevent tokens from being forever locked. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom(address from, address to, uint256 tokenId) external; /** * @dev Transfers `tokenId` token from `from` to `to`. * * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721 * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must * understand this adds an external call which potentially creates a reentrancy vulnerability. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * * Emits a {Transfer} event. */ function transferFrom(address from, address to, uint256 tokenId) external; /** * @dev Gives permission to `to` to transfer `tokenId` token to another account. * The approval is cleared when the token is transferred. * * Only a single account can be approved at a time, so approving the zero address clears previous approvals. * * Requirements: * * - The caller must own the token or be an approved operator. * - `tokenId` must exist. * * Emits an {Approval} event. */ function approve(address to, uint256 tokenId) external; /** * @dev Approve or remove `operator` as an operator for the caller. * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller. * * Requirements: * * - The `operator` cannot be the caller. * * Emits an {ApprovalForAll} event. */ function setApprovalForAll(address operator, bool approved) external; /** * @dev Returns the account approved for `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function getApproved(uint256 tokenId) external view returns (address operator); /** * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`. * * See {setApprovalForAll} */ function isApprovedForAll(address owner, address operator) external view returns (bool); } interface IERC721Enumerable is IERC721 { /** * @dev Returns the total amount of tokens stored by the contract. */ function totalSupply() external view returns (uint256); /** * @dev Returns a token ID owned by `owner` at a given `index` of its token list. * Use along with {balanceOf} to enumerate all of ``owner``'s tokens. */ function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256); /** * @dev Returns a token ID at a given `index` of all the tokens stored by the contract. * Use along with {totalSupply} to enumerate all tokens. */ function tokenByIndex(uint256 index) external view returns (uint256); } abstract contract ERC165 is IERC165 { /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IERC165).interfaceId; } } interface IERC721Receiver { /** * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom} * by `operator` from `from`, this function is called. * * It must return its Solidity selector to confirm the token transfer. * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted. * * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`. */ function onERC721Received( address operator, address from, uint256 tokenId, bytes calldata data ) external returns (bytes4); } interface IERC721Metadata is IERC721 { /** * @dev Returns the token collection name. */ function name() external view returns (string memory); /** * @dev Returns the token collection symbol. */ function symbol() external view returns (string memory); /** * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token. */ function tokenURI(uint256 tokenId) external view returns (string memory); } contract ERC721 is Context, ERC165, IERC721, IERC721Metadata { using Address for address; using Strings for uint256; // Token name string private _name; // Token symbol string private _symbol; // Mapping from token ID to owner address mapping(uint256 => address) private _owners; // Mapping owner address to token count mapping(address => uint256) private _balances; // Mapping from token ID to approved address mapping(uint256 => address) private _tokenApprovals; // Mapping from owner to operator approvals mapping(address => mapping(address => bool)) private _operatorApprovals; /** * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC721Metadata).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC721-balanceOf}. */ function balanceOf(address owner) public view virtual override returns (uint256) { require(owner != address(0), "ERC721: address zero is not a valid owner"); return _balances[owner]; } /** * @dev See {IERC721-ownerOf}. */ function ownerOf(uint256 tokenId) public view virtual override returns (address) { address owner = _ownerOf(tokenId); require(owner != address(0), "ERC721: invalid token ID"); return owner; } /** * @dev See {IERC721Metadata-name}. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev See {IERC721Metadata-symbol}. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev See {IERC721Metadata-tokenURI}. */ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { _requireMinted(tokenId); string memory baseURI = _baseURI(); return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : ""; } /** * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each * token will be the concatenation of the `baseURI` and the `tokenId`. Empty * by default, can be overridden in child contracts. */ function _baseURI() internal view virtual returns (string memory) { return ""; } /** * @dev See {IERC721-approve}. */ function approve(address to, uint256 tokenId) public virtual override { address owner = ERC721.ownerOf(tokenId); require(to != owner, "ERC721: approval to current owner"); require( _msgSender() == owner || isApprovedForAll(owner, _msgSender()), "ERC721: approve caller is not token owner or approved for all" ); _approve(to, tokenId); } /** * @dev See {IERC721-getApproved}. */ function getApproved(uint256 tokenId) public view virtual override returns (address) { _requireMinted(tokenId); return _tokenApprovals[tokenId]; } /** * @dev See {IERC721-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public virtual override { _setApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC721-isApprovedForAll}. */ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { return _operatorApprovals[owner][operator]; } /** * @dev See {IERC721-transferFrom}. */ function transferFrom(address from, address to, uint256 tokenId) public virtual override { //solhint-disable-next-line max-line-length require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved"); _transfer(from, to, tokenId); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override { safeTransferFrom(from, to, tokenId, ""); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public virtual override { require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved"); _safeTransfer(from, to, tokenId, data); } /** * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients * are aware of the ERC721 protocol to prevent tokens from being forever locked. * * `data` is additional data, it has no specified format and it is sent in call to `to`. * * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g. * implement alternative mechanisms to perform token transfer, such as signature-based. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function _safeTransfer(address from, address to, uint256 tokenId, bytes memory data) internal virtual { _transfer(from, to, tokenId); require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer"); } /** * @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist */ function _ownerOf(uint256 tokenId) internal view virtual returns (address) { return _owners[tokenId]; } /** * @dev Returns whether `tokenId` exists. * * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}. * * Tokens start existing when they are minted (`_mint`), * and stop existing when they are burned (`_burn`). */ function _exists(uint256 tokenId) internal view virtual returns (bool) { return _ownerOf(tokenId) != address(0); } /** * @dev Returns whether `spender` is allowed to manage `tokenId`. * * Requirements: * * - `tokenId` must exist. */ function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) { address owner = ERC721.ownerOf(tokenId); return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender); } /** * @dev Safely mints `tokenId` and transfers it to `to`. * * Requirements: * * - `tokenId` must not exist. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function _safeMint(address to, uint256 tokenId) internal virtual { _safeMint(to, tokenId, ""); } /** * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is * forwarded in {IERC721Receiver-onERC721Received} to contract recipients. */ function _safeMint(address to, uint256 tokenId, bytes memory data) internal virtual { _mint(to, tokenId); require( _checkOnERC721Received(address(0), to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer" ); } /** * @dev Mints `tokenId` and transfers it to `to`. * * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible * * Requirements: * * - `tokenId` must not exist. * - `to` cannot be the zero address. * * Emits a {Transfer} event. */ function _mint(address to, uint256 tokenId) internal virtual { require(to != address(0), "ERC721: mint to the zero address"); require(!_exists(tokenId), "ERC721: token already minted"); _beforeTokenTransfer(address(0), to, tokenId, 1); // Check that tokenId was not minted by `_beforeTokenTransfer` hook require(!_exists(tokenId), "ERC721: token already minted"); unchecked { // Will not overflow unless all 2**256 token ids are minted to the same owner. // Given that tokens are minted one by one, it is impossible in practice that // this ever happens. Might change if we allow batch minting. // The ERC fails to describe this case. _balances[to] += 1; } _owners[tokenId] = to; emit Transfer(address(0), to, tokenId); _afterTokenTransfer(address(0), to, tokenId, 1); } /** * @dev Destroys `tokenId`. * The approval is cleared when the token is burned. * This is an internal function that does not check if the sender is authorized to operate on the token. * * Requirements: * * - `tokenId` must exist. * * Emits a {Transfer} event. */ function _burn(uint256 tokenId) internal virtual { address owner = ERC721.ownerOf(tokenId); _beforeTokenTransfer(owner, address(0), tokenId, 1); // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook owner = ERC721.ownerOf(tokenId); // Clear approvals delete _tokenApprovals[tokenId]; unchecked { // Cannot overflow, as that would require more tokens to be burned/transferred // out than the owner initially received through minting and transferring in. _balances[owner] -= 1; } delete _owners[tokenId]; emit Transfer(owner, address(0), tokenId); _afterTokenTransfer(owner, address(0), tokenId, 1); } /** * @dev Transfers `tokenId` from `from` to `to`. * As opposed to {transferFrom}, this imposes no restrictions on msg.sender. * * Requirements: * * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * * Emits a {Transfer} event. */ function _transfer(address from, address to, uint256 tokenId) internal virtual { require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner"); require(to != address(0), "ERC721: transfer to the zero address"); _beforeTokenTransfer(from, to, tokenId, 1); // Check that tokenId was not transferred by `_beforeTokenTransfer` hook require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner"); // Clear approvals from the previous owner delete _tokenApprovals[tokenId]; unchecked { // `_balances[from]` cannot overflow for the same reason as described in `_burn`: // `from`'s balance is the number of token held, which is at least one before the current // transfer. // `_balances[to]` could overflow in the conditions described in `_mint`. That would require // all 2**256 token ids to be minted, which in practice is impossible. _balances[from] -= 1; _balances[to] += 1; } _owners[tokenId] = to; emit Transfer(from, to, tokenId); _afterTokenTransfer(from, to, tokenId, 1); } /** * @dev Approve `to` to operate on `tokenId` * * Emits an {Approval} event. */ function _approve(address to, uint256 tokenId) internal virtual { _tokenApprovals[tokenId] = to; emit Approval(ERC721.ownerOf(tokenId), to, tokenId); } /** * @dev Approve `operator` to operate on all of `owner` tokens * * Emits an {ApprovalForAll} event. */ function _setApprovalForAll(address owner, address operator, bool approved) internal virtual { require(owner != operator, "ERC721: approve to caller"); _operatorApprovals[owner][operator] = approved; emit ApprovalForAll(owner, operator, approved); } /** * @dev Reverts if the `tokenId` has not been minted yet. */ function _requireMinted(uint256 tokenId) internal view virtual { require(_exists(tokenId), "ERC721: invalid token ID"); } /** * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address. * The call is not executed if the target address is not a contract. * * @param from address representing the previous owner of the given token ID * @param to target address that will receive the tokens * @param tokenId uint256 ID of the token to be transferred * @param data bytes optional data to send along with the call * @return bool whether the call correctly returned the expected magic value */ function _checkOnERC721Received( address from, address to, uint256 tokenId, bytes memory data ) private returns (bool) { if (to.isContract()) { try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) { return retval == IERC721Receiver.onERC721Received.selector; } catch (bytes memory reason) { if (reason.length == 0) { revert("ERC721: transfer to non ERC721Receiver implementer"); } else { /// @solidity memory-safe-assembly assembly { revert(add(32, reason), mload(reason)) } } } } else { return true; } } /** * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1. * * Calling conditions: * * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`. * - When `from` is zero, the tokens will be minted for `to`. * - When `to` is zero, ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * - `batchSize` is non-zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 /* firstTokenId */, uint256 batchSize ) internal virtual { if (batchSize > 1) { if (from != address(0)) { _balances[from] -= batchSize; } if (to != address(0)) { _balances[to] += batchSize; } } } /** * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1. * * Calling conditions: * * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`. * - When `from` is zero, the tokens were minted for `to`. * - When `to` is zero, ``from``'s tokens were burned. * - `from` and `to` are never both zero. * - `batchSize` is non-zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal virtual {} } abstract contract ERC721Enumerable is ERC721, IERC721Enumerable { // Mapping from owner to list of owned token IDs mapping(address => mapping(uint256 => uint256)) private _ownedTokens; // Mapping from token ID to index of the owner tokens list mapping(uint256 => uint256) private _ownedTokensIndex; // Array with all token ids, used for enumeration uint256[] private _allTokens; // Mapping from token id to position in the allTokens array mapping(uint256 => uint256) private _allTokensIndex; /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) { return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}. */ function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) { require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds"); return _ownedTokens[owner][index]; } /** * @dev See {IERC721Enumerable-totalSupply}. */ function totalSupply() public view virtual override returns (uint256) { return _allTokens.length; } /** * @dev See {IERC721Enumerable-tokenByIndex}. */ function tokenByIndex(uint256 index) public view virtual override returns (uint256) { require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds"); return _allTokens[index]; } /** * @dev See {ERC721-_beforeTokenTransfer}. */ function _beforeTokenTransfer( address from, address to, uint256 firstTokenId, uint256 batchSize ) internal virtual override { super._beforeTokenTransfer(from, to, firstTokenId, batchSize); if (batchSize > 1) { // Will only trigger during construction. Batch transferring (minting) is not available afterwards. revert("ERC721Enumerable: consecutive transfers not supported"); } uint256 tokenId = firstTokenId; if (from == address(0)) { _addTokenToAllTokensEnumeration(tokenId); } else if (from != to) { _removeTokenFromOwnerEnumeration(from, tokenId); } if (to == address(0)) { _removeTokenFromAllTokensEnumeration(tokenId); } else if (to != from) { _addTokenToOwnerEnumeration(to, tokenId); } } /** * @dev Private function to add a token to this extension's ownership-tracking data structures. * @param to address representing the new owner of the given token ID * @param tokenId uint256 ID of the token to be added to the tokens list of the given address */ function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private { uint256 length = ERC721.balanceOf(to); _ownedTokens[to][length] = tokenId; _ownedTokensIndex[tokenId] = length; } /** * @dev Private function to add a token to this extension's token tracking data structures. * @param tokenId uint256 ID of the token to be added to the tokens list */ function _addTokenToAllTokensEnumeration(uint256 tokenId) private { _allTokensIndex[tokenId] = _allTokens.length; _allTokens.push(tokenId); } /** * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for * gas optimizations e.g. when performing a transfer operation (avoiding double writes). * This has O(1) time complexity, but alters the order of the _ownedTokens array. * @param from address representing the previous owner of the given token ID * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address */ function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private { // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and // then delete the last slot (swap and pop). uint256 lastTokenIndex = ERC721.balanceOf(from) - 1; uint256 tokenIndex = _ownedTokensIndex[tokenId]; // When the token to delete is the last token, the swap operation is unnecessary if (tokenIndex != lastTokenIndex) { uint256 lastTokenId = _ownedTokens[from][lastTokenIndex]; _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index } // This also deletes the contents at the last position of the array delete _ownedTokensIndex[tokenId]; delete _ownedTokens[from][lastTokenIndex]; } /** * @dev Private function to remove a token from this extension's token tracking data structures. * This has O(1) time complexity, but alters the order of the _allTokens array. * @param tokenId uint256 ID of the token to be removed from the tokens list */ function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private { // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and // then delete the last slot (swap and pop). uint256 lastTokenIndex = _allTokens.length - 1; uint256 tokenIndex = _allTokensIndex[tokenId]; // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding // an 'if' statement (like in _removeTokenFromOwnerEnumeration) uint256 lastTokenId = _allTokens[lastTokenIndex]; _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index // This also deletes the contents at the last position of the array delete _allTokensIndex[tokenId]; _allTokens.pop(); } } abstract contract BibliotecaERC721 is ERC721, Ownable, ERC721Enumerable { function _beforeTokenTransfer( address from, address to, uint256 firstTokenId, uint256 batchSize) internal override(ERC721, ERC721Enumerable) { super._beforeTokenTransfer(from, to, firstTokenId, batchSize); } function supportsInterface(bytes4 interfaceId) public view override(ERC721, ERC721Enumerable) returns (bool) { return super.supportsInterface(interfaceId); } }