// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title XBoo Token
 * @dev Implementation of the XBoo ERC20 token.
 */
contract XBooToken {
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    address public contractOwner;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    modifier onlyOwner() {
        require(msg.sender == contractOwner, "Only the contract owner can call this function.");
        _;
    }

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        uint256 _totalSupply
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        totalSupply = _totalSupply * (10 ** uint256(decimals));
        contractOwner = msg.sender;
        balanceOf[contractOwner] = totalSupply;
        emit Transfer(address(0), contractOwner, totalSupply);
    }

    /**
     * @dev Transfer token for a specified address.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
    function transfer(address to, uint256 value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     */
    function approve(address spender, uint256 value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Transfer tokens from one address to another.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     */
    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool) {
        require(
            allowance[from][msg.sender] >= value,
            "ERC20: transfer amount exceeds allowance"
        );
        _transfer(from, to, value);
        allowance[from][msg.sender] -= value;
        return true;
    }

    /**
     * @dev Internal transfer function.
     * @param from The address to transfer from.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
    function _transfer(
        address from,
        address to,
        uint256 value
    ) internal {
        require(to != address(0), "ERC20: transfer to the zero address");
        require(
            balanceOf[from] >= value,
            "ERC20: transfer amount exceeds balance"
        );
        balanceOf[from] -= value;
        balanceOf[to] += value;
        emit Transfer(from, to, value);
    }

    /**
     * @dev Internal function to approve an address to spend another's tokens.
     * @param owner The address that owns the tokens.
     * @param spender The address that will spend the tokens.
     * @param value The number of tokens to allow.
     */
    function _approve(
        address owner,
        address spender,
        uint256 value
    ) internal {
        require(spender != address(0), "ERC20: approve to the zero address");
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     * @notice Renouncing to ownership will leave the contract without an owner,
     * which will prevent functions that only the owner can execute from being called.
     */
    function renounceOwnership() external onlyOwner {
        emit OwnershipTransferred(contractOwner, address(0));
        contractOwner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     * @param newOwner The address to transfer ownership to.
     */
    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "ERC20: new owner is the zero address");
        emit OwnershipTransferred(contractOwner, newOwner);
        contractOwner = newOwner;
    }
}

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