// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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);
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// 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;
    }
}

// File: contracts/interfaces/IUnitapPass.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

interface IUnitapPass {
    function safeMint(address to) external;
}

// File: contracts/UnitapPassBatchSale.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import "@openzeppelin/contracts/access/Ownable.sol";
import "./interfaces/IUnitapPass.sol";

contract UnitapPassBatchSale is Ownable {
    uint32 public constant MAX_SALE_COUNT = 2000;

    address public unitapPass;
    address public safe; // all funds will be withdrawn to this address

    uint32 public totalSoldCount;
    uint32 public batchSize;
    uint32 public batchSoldCount;
    uint256 public price;

    constructor(
        address unitapPass_,
        address safe_,
        uint256 price_
    ) Ownable() {
        unitapPass = unitapPass_;
        safe = safe_;
        price = price_;
    }

    event StartBatch(uint32 batchSize);
    event MultiMint(address to, uint32 count);
    event WithdrawETH(uint256 amount, address to);

    error InvalidBatchSize();
    error CurrentBatchSoldOut();
    error InsufficientFunds();

    function startBatch(uint32 batchSize_) external onlyOwner {
        if (totalSoldCount + batchSize_ > MAX_SALE_COUNT) {
            revert InvalidBatchSize();
        }

        batchSize = batchSize_;
        batchSoldCount = 0;

        emit StartBatch(batchSize);
    }

    function multiMint(uint32 count, address to) external payable {
        if (batchSoldCount + count > batchSize) revert CurrentBatchSoldOut();

        uint256 totalValue = price * count;

        if (msg.value < totalValue) revert InsufficientFunds();

        for (uint32 i = 0; i < count; i++) {
            IUnitapPass(unitapPass).safeMint(to);
        }

        batchSoldCount += count;
        totalSoldCount += count;

        // refund extra ETH
        if (msg.value > totalValue) {
            payable(msg.sender).transfer(msg.value - totalValue);
        }

        emit MultiMint(to, count);
    }

    function withdrawETH() external {
        uint256 amount = address(this).balance;
        payable(safe).transfer(amount);
        emit WithdrawETH(amount, safe);
    }
}