// SPDX-License-Identifier: MIT

// Rick Roll Token (ERC-20) - $RICKROLL

//      ___                       ___           ___                    ___           ___           ___       ___ 
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// /:/\:\ \:\__\  __/:/\/__/ /:/__/ \:\__\ /:/\:::::\__\          /:/\:\ \:\__\ /:/__/ \:\__\ /:/__/    /:/__/   
// \/_|::\/:/  / /\/:/  /    \:\  \  \/__/ \/_|:|~~|~             \/_|::\/:/  / \:\  \ /:/  / \:\  \    \:\  \   
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//
//

pragma solidity ^0.8.0;

// Importing required OpenZeppelin contracts
// Context.sol
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// IERC20.sol
interface IERC20 {
    // Returns the total supply of tokens
    function totalSupply() external view returns (uint256);

    // Returns the token balance of specific account
    function balanceOf(address account) external view returns (uint256);

    // Transfers tokens from the function caller to another address
    function transfer(address recipient, uint256 amount) external returns (bool);

    // Returns the remaining number of tokens that spender will be allowed to spend on behalf of owner
    function allowance(address owner, address spender) external view returns (uint256);

    // Sets the amount of tokens that an address can spend on behalf of the msg.sender
    function approve(address spender, uint256 amount) external returns (bool);

    // Transfers tokens from one address to another
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);


    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// IERC20Metadata.sol
interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

// Ownable.sol
contract Ownable is Context {

     // The owner of the contract
    address private _owner;

    
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _setOwner(_msgSender());
    }

    // Returns the current owner
    function owner() public view virtual returns (address) {
        return _owner;
    }

    // Makes a function callable only by the owner
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    // Allows the current owner to relinquish control of the contract
    function renounceOwnership() public virtual onlyOwner {
        _setOwner(address(0));
    }


    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// ERC20.sol
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        _approve(sender, _msgSender(), currentAllowance - amount);

        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        _approve(_msgSender(), spender, currentAllowance - subtractedValue);

        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        _balances[sender] = senderBalance - amount;
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }

    //burns tokens
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        _balances[account] = accountBalance - amount;
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// RickRoll Token Logic
contract RickRoll is Ownable, ERC20 {
    bool public limited;
    uint256 public maxHoldingAmount;
    uint256 public minHoldingAmount;
    mapping(address => bool) public blacklists;
    bool public blacklistEnabled;

    constructor(uint256 _totalSupply) ERC20("Rick Roll", "RICKROLL") {
        _mint(msg.sender, _totalSupply);
    }

    // blacklists a sniper bot before contract ownership is revoked
    function blacklist(address _address, bool _isBlacklisting) external onlyOwner {
        blacklists[_address] = _isBlacklisting;
    }

    function setRule(bool _limited, uint256 _maxHoldingAmount, uint256 _minHoldingAmount) external onlyOwner {
        limited = _limited;
        maxHoldingAmount = _maxHoldingAmount;
        minHoldingAmount = _minHoldingAmount;
    }

    function setBlacklistEnabled(bool _enabled) external onlyOwner {
        blacklistEnabled = _enabled;
    }

    // checks for blacklist users
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) override internal virtual {
        if (blacklistEnabled) {
            require(!blacklists[to] && !blacklists[from], "Blacklisted");
        }

        if (limited && from != owner()) {
            require(super.balanceOf(to) + amount <= maxHoldingAmount && super.balanceOf(to) + amount >= minHoldingAmount, "Forbid");
        }
    }

    //burns any tokens inputted from wallet
    function burn(uint256 value) external {
        _burn(msg.sender, value);
    }
}