// File: contracts/MintyImplementation.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.5.10;


/**
 * @title IERC165
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
 */
interface IERC165 {
    /**
     * @notice Query if a contract implements an interface
     * @param interfaceId The interface identifier, as specified in ERC-165
     * @dev Interface identification is specified in ERC-165. This function
     * uses less than 30,000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

/**
 * @title ERC721 Non-Fungible Token Standard basic interface
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract IERC721 is IERC165 {
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 indexed tokenId
    );
    event Approval(
        address indexed owner,
        address indexed approved,
        uint256 indexed tokenId
    );
    event ApprovalForAll(
        address indexed owner,
        address indexed operator,
        bool approved
    );

    function balanceOf(address owner) public view returns (uint256 balance);

    function ownerOf(uint256 tokenId) public view returns (address owner);

    function approve(address to, uint256 tokenId) public;

    function getApproved(uint256 tokenId) public view returns (address operator);

    function setApprovalForAll(address operator, bool _approved) public;

    function isApprovedForAll(address owner, address operator)
    public
    view
    returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public;

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public;

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public;
}

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract IERC721Enumerable is IERC721 {
    function totalSupply() public view returns (uint256);

    function tokenOfOwnerByIndex(address owner, uint256 index)
    public
    view
    returns (uint256 tokenId);

    function tokenByIndex(uint256 index) public view returns (uint256);
}

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
contract IERC721Receiver {
    /**
     * @notice Handle the receipt of an NFT
     * @dev The ERC721 smart contract calls this function on the recipient
     * after a `safeTransfer`. This function MUST return the function selector,
     * otherwise the caller will revert the transaction. The selector to be
     * returned can be obtained as `this.onERC721Received.selector`. This
     * function MAY throw to revert and reject the transfer.
     * Note: the ERC721 contract address is always the message sender.
     * @param operator The address which called `safeTransferFrom` function
     * @param from The address which previously owned the token
     * @param tokenId The NFT identifier which is being transferred
     * @param data Additional data with no specified format
     * @return `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes memory data
    ) public returns (bytes4);
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    /**
     * @dev Multiplies two numbers, throws on overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
        // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        c = a * b;
        assert(c / a == b);
        return c;
    }

    /**
     * @dev Integer division of two numbers, truncating the quotient.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        // uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return a / b;
    }

    /**
     * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    /**
     * @dev Adds two numbers, throws on overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * Utility library of inline functions on addresses
 */
library Address {
    /**
     * Returns whether the target address is a contract
     * @dev This function will return false if invoked during the constructor of a contract,
     *  as the code is not actually created until after the constructor finishes.
     * @param addr address to check
     * @return whether the target address is a contract
     */
    function isContract(address addr) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solium-disable-next-line security/no-inline-assembly
        assembly {
            size := extcodesize(addr)
        }
        return size > 0;
    }
}

/**
 * @title ERC165
 * @author Matt Condon (@shrugs)
 * @dev Implements ERC165 using a lookup table.
 */
contract ERC165 is IERC165 {
    bytes4 private constant _InterfaceId_ERC165 = 0x01ffc9a7;
    /**
     * 0x01ffc9a7 ===
     *   bytes4(keccak256('supportsInterface(bytes4)'))
     */

    /**
     * @dev a mapping of interface id to whether or not it's supported
     */
    mapping(bytes4 => bool) private _supportedInterfaces;

    /**
     * @dev A contract implementing SupportsInterfaceWithLookup
     * implement ERC165 itself
     */
    constructor() internal {
        _registerInterface(_InterfaceId_ERC165);
    }

    /**
     * @dev implement supportsInterface(bytes4) using a lookup table
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
        return _supportedInterfaces[interfaceId];
    }

    /**
     * @dev internal method for registering an interface
     */
    function _registerInterface(bytes4 interfaceId) internal {
        require(interfaceId != 0xffffffff);
        _supportedInterfaces[interfaceId] = true;
    }
}

/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract ERC721 is ERC165, IERC721 {
    using SafeMath for uint256;
    using Address for address;

    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;

    // Mapping from token ID to owner
    mapping(uint256 => address) private _tokenOwner;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to number of owned token
    mapping(address => uint256) private _ownedTokensCount;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    bytes4 private constant _InterfaceId_ERC721 = 0x80ac58cd;

    /*
     * 0x80ac58cd ===
     *   bytes4(keccak256('balanceOf(address)')) ^
     *   bytes4(keccak256('ownerOf(uint256)')) ^
     *   bytes4(keccak256('approve(address,uint256)')) ^
     *   bytes4(keccak256('getApproved(uint256)')) ^
     *   bytes4(keccak256('setApprovalForAll(address,bool)')) ^
     *   bytes4(keccak256('isApprovedForAll(address,address)')) ^
     *   bytes4(keccak256('transferFrom(address,address,uint256)')) ^
     *   bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
     *   bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
     */

    constructor() public {
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_InterfaceId_ERC721);
    }

    /**
     * @dev Gets the balance of the specified address
     * @param owner address to query the balance of
     * @return uint256 representing the amount owned by the passed address
     */
    function balanceOf(address owner) public view returns (uint256) {
        require(owner != address(0));
        return _ownedTokensCount[owner];
    }

    /**
     * @dev Gets the owner of the specified token ID
     * @param tokenId uint256 ID of the token to query the owner of
     * @return owner address currently marked as the owner of the given token ID
     */
    function ownerOf(uint256 tokenId) public view returns (address) {
        address owner = _tokenOwner[tokenId];
        require(owner != address(0));
        return owner;
    }

    /**
     * @dev Approves another address to transfer the given token ID
     * The zero address indicates there is no approved address.
     * There can only be one approved address per token at a given time.
     * Can only be called by the token owner or an approved operator.
     * @param to address to be approved for the given token ID
     * @param tokenId uint256 ID of the token to be approved
     */
    function approve(address to, uint256 tokenId) public {
        address owner = ownerOf(tokenId);
        require(to != owner);
        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));

        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Gets the approved address for a token ID, or zero if no address set
     * Reverts if the token ID does not exist.
     * @param tokenId uint256 ID of the token to query the approval of
     * @return address currently approved for the given token ID
     */
    function getApproved(uint256 tokenId) public view returns (address) {
        require(_exists(tokenId));
        return _tokenApprovals[tokenId];
    }

    /**
     * @dev Sets or unsets the approval of a given operator
     * An operator is allowed to transfer all tokens of the sender on their behalf
     * @param to operator address to set the approval
     * @param approved representing the status of the approval to be set
     */
    function setApprovalForAll(address to, bool approved) public {
        require(to != msg.sender);
        _operatorApprovals[msg.sender][to] = approved;
        emit ApprovalForAll(msg.sender, to, approved);
    }

    /**
     * @dev Tells whether an operator is approved by a given owner
     * @param owner owner address which you want to query the approval of
     * @param operator operator address which you want to query the approval of
     * @return bool whether the given operator is approved by the given owner
     */
    function isApprovedForAll(address owner, address operator)
    public
    view
    returns (bool)
    {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev Transfers the ownership of a given token ID to another address
     * Usage of this method is discouraged, use `safeTransferFrom` whenever possible
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public {
        require(_isApprovedOrOwner(msg.sender, tokenId));
        require(to != address(0));

        _clearApproval(from, tokenId);
        _removeTokenFrom(from, tokenId);
        _addTokenTo(to, tokenId);

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     *
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public {
        // solium-disable-next-line arg-overflow
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev Safely transfers the ownership of a given token ID to another address
     * If the target address is a contract, it must implement `onERC721Received`,
     * which is called upon a safe transfer, and return the magic value
     * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
     * the transfer is reverted.
     * Requires the msg sender to be the owner, approved, or operator
     * @param from current owner of the token
     * @param to address to receive the ownership of the given token ID
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes data to send along with a safe transfer check
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public {
        transferFrom(from, to, tokenId);
        // solium-disable-next-line arg-overflow
        require(_checkOnERC721Received(from, to, tokenId, _data));
    }

    /**
     * @dev Returns whether the specified token exists
     * @param tokenId uint256 ID of the token to query the existence of
     * @return whether the token exists
     */
    function _exists(uint256 tokenId) internal view returns (bool) {
        address owner = _tokenOwner[tokenId];
        return owner != address(0);
    }

    /**
     * @dev Returns whether the given spender can transfer a given token ID
     * @param spender address of the spender to query
     * @param tokenId uint256 ID of the token to be transferred
     * @return bool whether the msg.sender is approved for the given token ID,
     *  is an operator of the owner, or is the owner of the token
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId)
    internal
    view
    returns (bool)
    {
        address owner = ownerOf(tokenId);
        // Disable solium check because of
        // https://github.com/duaraghav8/Solium/issues/175
        // solium-disable-next-line operator-whitespace
        return (spender == owner ||
        getApproved(tokenId) == spender ||
        isApprovedForAll(owner, spender));
    }

    /**
     * @dev Internal function to mint a new token
     * Reverts if the given token ID already exists
     * @param to The address that will own the minted token
     * @param tokenId uint256 ID of the token to be minted by the msg.sender
     */
    function _mint(address to, uint256 tokenId) internal {
        require(to != address(0));

        _addTokenTo(to, tokenId);
        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Internal function to burn a specific token
     * Reverts if the token does not exist
     * @param tokenId uint256 ID of the token being burned by the msg.sender
     */
    function _burn(address owner, uint256 tokenId) internal {
        _clearApproval(owner, tokenId);
        _removeTokenFrom(owner, tokenId);
        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Internal function to add a token ID to the list of a given address
     * Note that this function is left internal to make ERC721Enumerable possible, but is not
     * intended to be called by custom derived contracts: in particular, it emits no Transfer event.
     * @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 _addTokenTo(address to, uint256 tokenId) internal {
        require(_tokenOwner[tokenId] == address(0));
        _tokenOwner[tokenId] = to;
        _ownedTokensCount[to] = _ownedTokensCount[to].add(1);
    }

    /**
     * @dev Internal function to remove a token ID from the list of a given address
     * Note that this function is left internal to make ERC721Enumerable possible, but is not
     * intended to be called by custom derived contracts: in particular, it emits no Transfer event,
     * and doesn't clear approvals.
     * @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 _removeTokenFrom(address from, uint256 tokenId) internal {
        require(ownerOf(tokenId) == from);
        _ownedTokensCount[from] = _ownedTokensCount[from].sub(1);
        _tokenOwner[tokenId] = address(0);
    }

    /**
     * @dev Internal function to invoke `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 whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal returns (bool) {
        if (!to.isContract()) {
            return true;
        }
        bytes4 retval = IERC721Receiver(to).onERC721Received(
            msg.sender,
            from,
            tokenId,
            _data
        );
        return (retval == _ERC721_RECEIVED);
    }

    /**
     * @dev Private function to clear current approval of a given token ID
     * Reverts if the given address is not indeed the owner of the token
     * @param owner owner of the token
     * @param tokenId uint256 ID of the token to be transferred
     */
    function _clearApproval(address owner, uint256 tokenId) private {
        require(ownerOf(tokenId) == owner);
        if (_tokenApprovals[tokenId] != address(0)) {
            _tokenApprovals[tokenId] = address(0);
        }
    }
}

contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => 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;

    bytes4 private constant _InterfaceId_ERC721Enumerable = 0x780e9d63;

    /**
     * 0x780e9d63 ===
     *   bytes4(keccak256('totalSupply()')) ^
     *   bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) ^
     *   bytes4(keccak256('tokenByIndex(uint256)'))
     */

    /**
     * @dev Constructor function
     */
    constructor() public {
        // register the supported interface to conform to ERC721 via ERC165
        _registerInterface(_InterfaceId_ERC721Enumerable);
    }

    /**
     * @dev Gets the token ID at a given index of the tokens list of the requested owner
     * @param owner address owning the tokens list to be accessed
     * @param index uint256 representing the index to be accessed of the requested tokens list
     * @return uint256 token ID at the given index of the tokens list owned by the requested address
     */
    function tokenOfOwnerByIndex(address owner, uint256 index)
    public
    view
    returns (uint256)
    {
        require(index < balanceOf(owner));
        return _ownedTokens[owner][index];
    }

    /**
     * @dev Gets the total amount of tokens stored by the contract
     * @return uint256 representing the total amount of tokens
     */
    function totalSupply() public view returns (uint256) {
        return _allTokens.length;
    }

    /**
     * @dev Gets the token ID at a given index of all the tokens in this contract
     * Reverts if the index is greater or equal to the total number of tokens
     * @param index uint256 representing the index to be accessed of the tokens list
     * @return uint256 token ID at the given index of the tokens list
     */
    function tokenByIndex(uint256 index) public view returns (uint256) {
        require(index < totalSupply());
        return _allTokens[index];
    }

    /**
     * @dev Internal function to add a token ID to the list of a given address
     * This function is internal due to language limitations, see the note in ERC721.sol.
     * It is not intended to be called by custom derived contracts: in particular, it emits no Transfer event.
     * @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 _addTokenTo(address to, uint256 tokenId) internal {
        super._addTokenTo(to, tokenId);
        uint256 length = _ownedTokens[to].length;
        _ownedTokens[to].push(tokenId);
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Internal function to remove a token ID from the list of a given address
     * This function is internal due to language limitations, see the note in ERC721.sol.
     * It is not intended to be called by custom derived contracts: in particular, it emits no Transfer event,
     * and doesn't clear approvals.
     * @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 _removeTokenFrom(address from, uint256 tokenId) internal {
        super._removeTokenFrom(from, tokenId);

        // To prevent a gap in the array, we store the last token in the index of the token to delete, and
        // then delete the last slot.
        uint256 tokenIndex = _ownedTokensIndex[tokenId];
        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
        uint256 lastToken = _ownedTokens[from][lastTokenIndex];

        _ownedTokens[from][tokenIndex] = lastToken;
        // This also deletes the contents at the last position of the array
        _ownedTokens[from].length--;

        // Note that this will handle single-element arrays. In that case, both tokenIndex and lastTokenIndex are going to
        // be zero. Then we can make sure that we will remove tokenId from the ownedTokens list since we are first swapping
        // the lastToken to the first position, and then dropping the element placed in the last position of the list

        _ownedTokensIndex[tokenId] = 0;
        _ownedTokensIndex[lastToken] = tokenIndex;
    }

    /**
     * @dev Internal function to mint a new token
     * Reverts if the given token ID already exists
     * @param to address the beneficiary that will own the minted token
     * @param tokenId uint256 ID of the token to be minted by the msg.sender
     */
    function _mint(address to, uint256 tokenId) internal {
        super._mint(to, tokenId);

        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    /**
     * @dev Internal function to burn a specific token
     * Reverts if the token does not exist
     * @param owner owner of the token to burn
     * @param tokenId uint256 ID of the token being burned by the msg.sender
     */
    function _burn(address owner, uint256 tokenId) internal {
        super._burn(owner, tokenId);

        // Reorg all tokens array
        uint256 tokenIndex = _allTokensIndex[tokenId];
        uint256 lastTokenIndex = _allTokens.length.sub(1);
        uint256 lastToken = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastToken;
        _allTokens[lastTokenIndex] = 0;

        _allTokens.length--;
        _allTokensIndex[tokenId] = 0;
        _allTokensIndex[lastToken] = tokenIndex;
    }
}

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 */
contract IERC721Metadata is IERC721 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function tokenURI(uint256 tokenId) external view returns (string memory);
}

contract ERC721Metadata is ERC165, ERC721, IERC721Metadata {
    // Token name
    string public _name;

    // Token symbol
    string public _symbol;

    // Optional mapping for token URIs
    string public _tokenURIs;

    bytes4 private constant InterfaceId_ERC721Metadata = 0x5b5e139f;

    /**
     * 0x5b5e139f ===
     *   bytes4(keccak256('name()')) ^
     *   bytes4(keccak256('symbol()')) ^
     *   bytes4(keccak256('tokenURI(uint256)'))
     */

    /**
     * @dev Constructor function
     */
    constructor(string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;

        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(InterfaceId_ERC721Metadata);
    }

    /**
     * @dev Gets the token name
     * @return string representing the token name
     */
    function name() external view returns (string memory) {
        return _name;
    }

    /**
     * @dev Gets the token symbol
     * @return string representing the token symbol
     */
    function symbol() external view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns an URI for a given token ID
     * Throws if the token ID does not exist. May return an empty string.
     * @param tokenId uint256 ID of the token to query
     */
    function tokenURI(uint256 tokenId) external view returns (string memory) {
        require(_exists(tokenId));
        return _tokenURIs;
    }

    /**
     * @dev Internal function to set the token URI for a given token
     * Reverts if the token ID does not exist
     * @param tokenId uint256 ID of the token to set its URI
     * @param uri string URI to assign
     */
    function _setTokenURI(uint256 tokenId, string memory uri) internal {
        require(_exists(tokenId));
        _tokenURIs = uri;
    }

    /**
     * @dev Internal function to burn a specific token
     * Reverts if the token does not exist
     * @param owner owner of the token to burn
     * @param tokenId uint256 ID of the token being burned by the msg.sender
     */
    function _burn(address owner, uint256 tokenId) internal {
        super._burn(owner, tokenId);
    }
}

/// @author Alchemy Team
/// @title Minty
/// @notice A contracts that lets users mint ERC721 tokens by sending ETH directly to it
contract Minty is ERC721Enumerable, ERC721Metadata {
    using SafeMath for uint256;

    string public url;
    address payable public owner;
    uint256 public tokenCost;
    uint256 public tokenCap;
    address public factoryContract;

    constructor(
        string memory name_,
        string memory symbol_
    ) public ERC721Metadata(name_, symbol_) {
        // Don't allow implementation to be initialized.
        factoryContract = address(1);
    }

    // events
    event CapRaised(uint256 indexed NewCap);
    event OwnerChanged(address payable NewOwner);

    // functions
    function initialize(
        string calldata name_,
        string calldata symbol_,
        string calldata url_,
        uint256 tokenCost_,
        uint256 tokenCap_,
        address payable owner_,
        address factoryContract_
    ) external {
        require(factoryContract == address(0), "already initialized");
        require(factoryContract_ != address(0), "factory can not be null");

        _name = name_;
        _symbol = symbol_;
        tokenCost = tokenCost_;
        url = url_;
        owner = owner_;
        _mint(owner, 0);
        _tokenURIs = url;
        tokenCap = tokenCap_;
        factoryContract = factoryContract_;

        _registerInterface(0x5b5e139f);
        _registerInterface(0x80ac58cd);
        _registerInterface(0x780e9d63);
        _registerInterface(0x01ffc9a7);
    }

    function changeCost(uint256 newcost) public {
        require(msg.sender == owner, "Only owner");
        tokenCost = newcost;
    }

    function RaiseCap(uint256 newtokens) public {
        require(msg.sender == owner, "Only owner");
        tokenCap = tokenCap.add(newtokens);
    }

    function changeOwner(address payable newOwner) public {
        require(msg.sender == owner, "Only owner");
        owner = newOwner;

        emit OwnerChanged(newOwner);
    }

    function withdrawETH() external {
        address payable alchemyRouter = IMintyFactory(factoryContract).getRouter();

        // send a 1% fee to the alchemyRouter
        IAlchemyRouter(alchemyRouter).deposit.value(address(this).balance / 100)();

        // transfer the rest to the owner
        owner.transfer(address(this).balance);
    }

    function() external payable {
        require(tokenCap > 0, "No token cap");
        require(tokenCap > totalSupply(), "Token cap too low");
        require(msg.value >= tokenCost, "msg.value too low");

        uint256 cost = msg.value.sub(tokenCost);
        _mint(msg.sender, totalSupply());
        msg.sender.transfer(cost);
    }

    function mintM(uint256 tokens, address[] memory to) public payable {
        require(tokenCap > 0, "No token cap");
        require(tokenCap >= totalSupply().add(tokens), "Token cap too low");
        require(tokens == to.length, "array token length mismatch");
        require(msg.value >= tokenCost.mul(tokens), "msg.value too low");

        uint256 cost = msg.value.sub(tokenCost.mul(tokens));

        for (uint256 i = 0; i < tokens; i++) {
            _mint(to[i], totalSupply());
        }
        msg.sender.transfer(cost);
    }
}


interface IMintyFactory {
    function getRouter() external view returns (address payable);
}


interface IAlchemyRouter {
    function deposit() external payable;
}