// SPDX-License-Identifier: MIT
pragma solidity ^0.8.15;
pragma experimental ABIEncoderV2;
/*

Bank of Tao

https://t.me/bankoftao

A new bank for generational wealth

*/

abstract contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _transferOwnership(msg.sender);
    }
    function owner() public view virtual returns (address) {
        return _owner;
    }
    modifier onlyOwner() {
        require(owner() == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

}

interface IERC20 {

    function balanceOf(address account) external view returns (uint256);
    function totalSupply() external view returns (uint256);
    function allowance(address owner, address spender) external view returns (uint256);
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
    function approve(address spender, uint256 amount) external returns (bool);
    function transfer(address recipient, uint256 amount) external returns (bool);
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

interface IERC20Metadata is IERC20 {
    function symbol() external view returns (string memory);
    function name() external view returns (string memory);
    function decimals() external view returns (uint8);
}

contract ERC20 is IERC20, IERC20Metadata {
    mapping(address => mapping(address => uint256)) private _allowances;
    mapping(address => uint256) private _balances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _symbol = symbol_;
        _name = name_;
    }
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }
    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(msg.sender, recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender] + addedValue);
        return true;
    }
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[msg.sender][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(msg.sender, spender, currentAllowance - subtractedValue);
        }

        return true;
    }
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][msg.sender];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, msg.sender, currentAllowance - amount);
        }

        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");

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _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");

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, 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);
    }
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IUniswapV2Router02 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
}

contract BankOfTaoToken is ERC20, Ownable {

    uint256 public maxTransactionAmount;
    uint256 public maxWallet;

    bool public limitsInEffect = true;

    mapping(address => bool) public isExcludedMaxTransactionAmount;
    mapping(address => bool) public automatedMarketMakerPairs;

    constructor() ERC20("Bank of Tao", "BANKOFTAO") {
        IUniswapV2Router02 uniswapV2Router = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        );

        isExcludedMaxTransactionAmount[address(uniswapV2Router)] = true;

        address uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
        
        isExcludedMaxTransactionAmount[uniswapV2Pair] = true;
        automatedMarketMakerPairs[uniswapV2Pair] = true;

        uint256 totalSupply = 100_000_000 * 1e18;

        maxTransactionAmount = totalSupply * 5 / 1000;
        maxWallet = totalSupply * 20 / 1000;

        isExcludedMaxTransactionAmount[owner()] = true;

        /*
            _mint is an internal function in ERC20.sol that is only called here,
            and CANNOT be called ever again
        */
        _mint(msg.sender, totalSupply);
    }

    function removeLimits() external onlyOwner returns (bool) {
        limitsInEffect = false;
        return true;
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        if (amount == 0) {
            super._transfer(from, to, 0);
            return;
        }

        if (limitsInEffect) {
            if (
                from != owner() &&
                to != owner()
            ) {

                if (
                    automatedMarketMakerPairs[from] &&
                    !isExcludedMaxTransactionAmount[to]
                ) {
                    require(
                        amount <= maxTransactionAmount,
                        "!maxTransactionAmount."
                    );
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "!maxWallet"
                    );
                }

                else if (
                    automatedMarketMakerPairs[to] &&
                    !isExcludedMaxTransactionAmount[from]
                ) {
                    require(
                        amount <= maxTransactionAmount,
                        "!maxTransactionAmount."
                    );
                } else if (!isExcludedMaxTransactionAmount[to]) {
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "!maxWallet"
                    );
                }
            }
        }

        super._transfer(from, to, amount);
    }
}