// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.2) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";

import "./IERC6982.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.

 Modified to make it non-transferable.

 */
contract ERC721Locked is IERC6982, 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;

  /**
   * @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_;
    emit DefaultLocked(true);
  }

  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
    return
      interfaceId == type(IERC6982).interfaceId ||
      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), "ERC721Locked: 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), "ERC721Locked: 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, uint256) public virtual override {
    revert("ERC721Locked: not approvable");
  }

  /**
   * @dev See {IERC721-getApproved}.
   */
  function getApproved(uint256 tokenId) public view virtual override returns (address) {
    _requireMinted(tokenId);
    return address(0);
  }

  function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
    return _owners[tokenId];
  }

  /**
   * @dev See {IERC721-setApprovalForAll}.
   */
  function setApprovalForAll(address, bool) public virtual override {
    revert("ERC721Locked: not approvable");
  }

  /**
   * @dev See {IERC721-isApprovedForAll}.
   */
  function isApprovedForAll(address, address) public view virtual override returns (bool) {
    return false;
  }

  /**
   * @dev See {IERC721-transferFrom}.
   */
  function transferFrom(address, address, uint256) public virtual override {
    revert("ERC721Locked: not transferable");
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(address, address, uint256) public virtual override {
    revert("ERC721Locked: not transferable");
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(address, address, uint256, bytes memory) public virtual override {
    revert("ERC721Locked: not transferable");
  }

  function _requireMinted(uint256 tokenId) internal view virtual {
    require(_exists(tokenId), "ERC721Locked: invalid token ID");
  }

  function _exists(uint256 tokenId) internal view virtual returns (bool) {
    return _ownerOf(tokenId) != address(0);
  }

  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), "ERC721Locked: 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), "ERC721Locked: mint to the zero address");
    require(!_exists(tokenId), "ERC721Locked: token already minted");

    _beforeTokenTransfer(address(0), to, tokenId, 1);

    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);
  }

  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;
      }
    }
  }

  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("ERC721Locked: transfer to non ERC721Receiver implementer");
        } else {
          /// @solidity memory-safe-assembly
          assembly {
            revert(add(32, reason), mload(reason))
          }
        }
      }
    } else {
      return true;
    }
  }

  function locked(uint256) external view virtual returns (bool) {
    return true;
  }

  function defaultLocked() external view virtual returns (bool) {
    return true;
  }
}