// SPDX-License-Identifier: BSD-3-Clause
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}


// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
pragma solidity ^0.8.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}


pragma solidity 0.8.9;

contract Delegated is Ownable{
  mapping(address => bool) internal _delegates;

  modifier onlyDelegates {
    require(_delegates[msg.sender], "Invalid delegate" );
    _;
  }

  constructor()
    Ownable(){
    setDelegate( owner(), true );
  }

  //onlyOwner
  function isDelegate( address addr ) external view onlyOwner returns( bool ){
    return _delegates[addr];
  }

  function setDelegate( address addr, bool isDelegate_ ) public onlyOwner{
    _delegates[addr] = isDelegate_;
  }

  function transferOwnership(address newOwner) public virtual override onlyOwner {
    _delegates[newOwner] = true;
    super.transferOwnership( newOwner );
  }
}


// OpenZeppelin Contracts (last updated v4.6.0) (utils/cryptography/MerkleProof.sol)
pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}


pragma solidity 0.8.9;

contract Merkle is Delegated{
  bytes32 internal merkleRoot = "";

  function setMerkleRoot( bytes32 merkleRoot_ ) public onlyDelegates{
    merkleRoot = merkleRoot_;
  }

  function _isValidProof(bytes32 leaf, bytes32[] memory proof) internal view returns( bool ){
    return MerkleProof.processProof( proof, leaf ) == merkleRoot;
  }
}


pragma solidity ^0.8.0;

interface IERC721B{
  function balanceOf( address ) external view returns( uint );
  function mintTo(uint16[] calldata quantity, address[] calldata recipient) external payable;
  function totalSupply() external view returns( uint );
}

interface IERC20Withdraw{
  function balanceOf(address account) external view returns (uint256);
  function transfer(address to, uint256 amount) external returns (bool);
}

interface IERC721Withdraw{
  function transferFrom(address from, address to, uint256 tokenId) external;
}
 
contract HashCatsProxy is Delegated, Merkle{
  using Address for address;

  struct MintConfig{
    address principle;
    address withdrawTo;
    uint16 maxMint;
    uint16 maxOrder;

    uint8 saleState;
  }

  struct PriceCurve{
    uint16 mark;
    uint256 price;
  }

  enum SaleState{
    NONE,
    PRESALE,
    MAINSALE
  }

  MintConfig public config = MintConfig(
    0x68cEDc921968dEbB2a85aEEE64292E8B88d49832,
    0x49bdF5aFDF2dfF8a0890c7A37fEc90c3ae816187,
       20,       //maxMint
       20,       //maxOrder

    uint8(SaleState.MAINSALE)
  );

  string public name = "HashCats: Proxy";
  string public symbol = "HC:P";
  PriceCurve[] public pricing;

  constructor(){
    setMerkleRoot( 0x470a6fb4633e18872e1bf4bb740c1985f5eed03b6a3b9d61eaf1548475f59142 );

    pricing.push( PriceCurve(     5, 0.030 ether ) );
    pricing.push( PriceCurve(    10, 0.025 ether ) );
    pricing.push( PriceCurve( 10000, 0.020 ether ) );
  }

  function balanceOf( address account ) public view returns( uint ){
    return IERC721B( config.principle ).balanceOf( account );
  }

  function totalSupply() public view returns( uint ){
    return IERC721B( config.principle ).totalSupply();
  }

  //payable
  function mint( uint16 quantity, bytes32[] calldata proof ) external payable {
    MintConfig memory cfg = config;

    require( quantity > 0,                              "Must order 1+" );
    require( quantity <= cfg.maxOrder,                  "Order too big" );
    require( balanceOf( msg.sender ) + quantity <= cfg.maxMint,    "Wallet limit reached" );
    require( msg.value >= calculateTotal( quantity ), "Ether sent is not correct" );

    if( cfg.saleState == uint8(SaleState.MAINSALE) ){
      //no-op
    }
    else if( cfg.saleState == uint8(SaleState.PRESALE) ){
      require( _isValidProof( keccak256( abi.encodePacked( msg.sender ) ), proof ), "You are not on the access list" );
    }
    else{
      revert( "Sale is not active" );
    }

    uint16[] memory quantitys = new uint16[](1);
    quantitys[0] = quantity;

    address[] memory recipients = new address[](1);
    recipients[0] = msg.sender;

    IERC721B( config.principle ).mintTo( quantitys, recipients );
  }

  function setConfig( MintConfig calldata config_ ) external onlyDelegates{
    config = config_;
  }

  function setPricingCurve( uint16[] calldata marks, uint256[] calldata newPrices ) external onlyDelegates {
    require( marks.length == newPrices.length, "must provide equal marks and prices" );
    while( marks.length > pricing.length ){
      pricing.pop();
    }

    uint16 prevMark = 0;
    for( uint256 i = 0; i < marks.length; ++i ){
      if( i > 0 )
        require( marks[i] > prevMark, "quantity marks must increase" );

      prevMark = marks[i];
      if( i == pricing.length )
        pricing.push();

      pricing[ i ] = PriceCurve( prevMark, newPrices[i] );
    }
  }


  //withdraw
  function withdraw() external onlyOwner {
    uint256 totalBalance = address(this).balance;
    require(totalBalance > 0, "no funds available");
    Address.sendValue(payable(config.withdrawTo), totalBalance);
  }

  function withdraw(address token) external {
    IERC20Withdraw erc20 = IERC20Withdraw(token);
    erc20.transfer( config.withdrawTo, erc20.balanceOf(address(this)) );
  }

  function withdraw(address token, uint256[] calldata tokenId) external {
    for( uint256 i = 0; i < tokenId.length; ++i ){
      IERC721Withdraw(token).transferFrom( address(this), config.withdrawTo, tokenId[i] );
    }
  }

  //view
  function calculateTotal( uint16 quantity ) public view returns( uint256 ){
    for( uint256 i = 0; i < pricing.length; ++i ){
      if( quantity < pricing[i].mark )
        return quantity * pricing[i].price;
    }

    revert( "Invalid quantity" );
  }
}