//  
//   ______   ____  _____  
// .' ____ \ |_   \|_   _| 
// | (___ \_|  |   \ | |   
//  _.____`.   | |\ \| |   
// | \____) | _| |_\   |_  
//  \______.'|_____|\____|  V2
// 
//  The Times 03/Jan/2009 Chancellor on brink of second bailout for banks
//  built on BASE

// SPDX-License-Identifier: MIT
// Compatible with OpenZeppelin Contracts ^5.0.0
pragma solidity ^0.8.22;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract BasedBlocks is Ownable {
    uint256 public constant HALVING_PERIOD = 150000;
    uint256 public constant INITIAL_TOKEN_REWARD = 500 ether;

    uint8 public currentDifficulty = 20;

    mapping(bytes32 => bool) public minedHash;
    mapping(address => Miner) public miners;

    uint256 public constant INITIAL_MINE_FEE = 0.00005 ether;
    uint256 public constant MINE_FEE_INCREMENT = 0.000002 ether; // each 8 bits increase
    uint256 public constant INITIAL_LEVEL_UPGRADE_COST = 0.0044 ether;

    uint256 public gameBlock;

    IERC20 public token;

    struct Miner {
        address miner;
        uint256 level;
        uint256 totalMined;
        uint256 referralCount;
        uint256 referralIncome;
        address referral;
    }

    struct MineCall {
        address user;
        uint256 seed;
        uint256 nonce;
        bytes32 solution;
    }

    struct Block {
        uint256 id;
        uint256 reward;
        address miner;
        uint256 timestamp;
    }

    event BlockEvent(
        uint256 indexed blockId,
        address indexed miner,
        uint256 reward,
        uint256 timestamp,
        uint8 difficulty,
        uint256 seed,
        uint256 nonce,
        bytes32 solution
    );
    event MinerCreated(address indexed miner, address indexed referral);
    event MinerLevelUpgraded(address indexed miner, uint256 newLevel);
    event DifficultyUpgraded(uint8 newDifficulty);

    constructor(
        address initialOwner,
        address tokenAddress
    ) Ownable(initialOwner) {
        token = IERC20(tokenAddress);
    }

    function mine(
        address user,
        uint256 seed,
        uint256 nonce,
        bytes32 solution,
        address referral
    ) external payable {
        require(msg.value >= calculateMineFee(), "Insufficient fee sent");

        _mine(user, seed, nonce, solution, referral);
    }

    function multicallMine(
        MineCall[] calldata calls,
        address referral
    ) external payable {
        uint256 totalFee = calculateMineFee() * calls.length;
        require(msg.value >= totalFee, "Insufficient fee sent");

        for (uint256 i = 0; i < calls.length; i++) {
            MineCall calldata call = calls[i];
            _mine(call.user, call.seed, call.nonce, call.solution, referral);
        }
    }

    function createOrGetMiner(
        address user,
        address referral
    ) internal returns (Miner storage miner) {
        if (miners[user].miner == address(0)) {
            miner = miners[user];
            miner.miner = user;
            miner.level = 0;
            miner.referral = referral;

            if (miners[referral].miner == address(0)) {
                miners[referral].miner = referral;
                miners[referral].level = 0;
                miners[referral].referral = address(0);
                miners[referral].referralCount = 1;
            } else {
                miners[referral].referralCount++;
            }

            emit MinerCreated(referral, address(0));
        }

        emit MinerCreated(user, referral);

        return miners[user];
    }

    function _mine(
        address user,
        uint256 seed,
        uint256 nonce,
        bytes32 solution,
        address referral
    ) internal {
        createOrGetMiner(user, referral);

        (bool success, bytes32 dataToHash) = verifySolution(
            user,
            seed,
            nonce,
            solution
        );

        require(success, "Solution is invalid");

        uint256 reward = calculateReward(miners[user].level);
        token.transfer(user, reward);

        if (miners[user].referral != address(0)) {
            uint256 referralReward = (reward * 10) / 100;
            token.transfer(miners[user].referral, referralReward);

            miners[miners[user].referral].referralIncome += referralReward;
        }

        miners[user].totalMined += reward;

        require(!minedHash[dataToHash], "Already mined");

        minedHash[dataToHash] = true;

        emit BlockEvent(
            gameBlock,
            user,
            reward,
            block.timestamp,
            currentDifficulty,
            seed,
            nonce,
            solution
        );

        gameBlock++;
    }

    function upgradeLevel(address user, address referral) external payable {
        createOrGetMiner(user, referral);

        require(
            msg.value >= calculateLevelUpgradeCost(miners[user].level),
            "Insufficient fee sent"
        );

        miners[user].level++;

        emit MinerLevelUpgraded(user, miners[user].level);
    }

    function getMineFee(uint256 length) public view returns (uint256) {
        uint256 mineFee = calculateMineFee();

        return mineFee * length;
    }

    function calculateLevelUpgradeCost(
        uint256 level
    ) public pure returns (uint256) {
        return INITIAL_LEVEL_UPGRADE_COST * (2 ** level);
    }

    function calculateReward(uint256 level) public view returns (uint256) {
        uint256 halvings = gameBlock / HALVING_PERIOD;
        uint256 reward = INITIAL_TOKEN_REWARD;

        // Apply halvings
        for (uint256 i = 0; i < halvings; i++) {
            reward = reward / 2;
        }

        if (level > 0) {
            for (uint256 i = 0; i < level; i++) {
                reward = (reward * 150) / 100;
            }
        }

        return reward;
    }

    function calculateMineFee() public view returns (uint256) {
        uint256 difficulty = currentDifficulty / 8;
        return INITIAL_MINE_FEE + (MINE_FEE_INCREMENT * difficulty);
    }

    function setDifficulty(uint8 newDifficulty) external onlyOwner {
        currentDifficulty = newDifficulty;

        emit DifficultyUpgraded(newDifficulty);
    }

    function verifySolution(
        address user,
        uint256 seed,
        uint256 nonce,
        bytes32 solution
    ) public view returns (bool success, bytes32 dataToHash) {
        dataToHash = keccak256(abi.encodePacked(user, seed, nonce));
        require(dataToHash == solution, "Invalid solution");

        success = true;

        for (uint8 i = 0; i < currentDifficulty; i++) {
            if (uint8(solution[i / 8]) & (1 << (7 - (i % 8))) != 0) {
                success = false;
                break;
            }
        }

        return (success, dataToHash);
    }

    function withdraw() external payable onlyOwner {
        (bool sent, ) = owner().call{value: address(this).balance}("");
        if (!sent) revert FailedToSendETH();
    }

    error FailedToSendETH();
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../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.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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);
    }
}

{
  "compilationTarget": {
    "BaseMine.sol": "BasedBlocks"
  },
  "evmVersion": "prague",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}