Metanopoly Tokenized Share

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

/**
 * @title Metanopoly Tokenized Share 4.0
 * @dev Metanopoly Tokenized Share (MTS), the core token of the Metanopoly ecosystem.
 */

contract MetanopolyTokenizedShare {
    // Token metadata
    string public constant name = "Metanopoly Tokenized Share";
    string public constant symbol = "MTS";
    uint8 public constant decimals = 18;
    uint256 public immutable totalSupply;

    // Owner of the contract
    address public immutable owner;

    // Mappings for balances and allowances
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    // Events
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    // Modifiers
    modifier onlyOwner() {
        require(msg.sender == owner, "Caller is not the owner");
        _;
    }

    /**
     * @dev Contract constructor initializes the total supply and assigns it to deployer.
     */
    constructor() {
        owner = msg.sender;
        totalSupply = 1_000_000_000 * 10 ** uint256(decimals); // 1 Billion tokens
        _balances[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    /**
     * @dev Returns the balance of a specific address.
     */
    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev Transfers tokens to a specified address.
     */
    function transfer(address recipient, uint256 amount) external returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

    /**
     * @dev Approves a spender with a specified allowance.
     */
    function approve(address spender, uint256 amount) external returns (bool) {
        require(spender != address(0), "Approve to zero address");
        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    /**
     * @dev Transfers tokens on behalf of an owner.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) {
        require(_allowances[sender][msg.sender] >= amount, "Allowance exceeded");
        _allowances[sender][msg.sender] -= amount;
        _transfer(sender, recipient, amount);
        return true;
    }

    /**
     * @dev Returns the remaining allowance for a spender.
     */
    function allowance(address owner_, address spender) external view returns (uint256) {
        return _allowances[owner_][spender];
    }

    /**
     * @dev Securely increases allowance to prevent front-running issues.
     */
    function increaseAllowance(address spender, uint256 addedValue) external returns (bool) {
        require(spender != address(0), "Increase allowance to zero address");
        _allowances[msg.sender][spender] += addedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }

    /**
     * @dev Securely decreases allowance to prevent front-running issues.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool) {
        require(spender != address(0), "Decrease allowance to zero address");
        uint256 currentAllowance = _allowances[msg.sender][spender];
        require(currentAllowance >= subtractedValue, "Allowance below zero");
        _allowances[msg.sender][spender] -= subtractedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }

    /**
     * @dev Internal transfer function with gas efficiency optimizations.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "Transfer from zero address");
        require(recipient != address(0), "Transfer to zero address");
        require(_balances[sender] >= amount, "Insufficient balance");

        _balances[sender] -= amount;
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    /**
     * @dev Prevents any minting after deployment.
     */
    function _mint(address, uint256) internal pure {
        revert("Minting disabled");
    }
}

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