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

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    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);
}

contract Zaro is IERC20 {
    string public name = "Zaro Zora";
    string public symbol = "ZARO";
    uint8 public decimals = 18;
    uint256 private _totalSupply;

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    address public owner;

    event OwnershipRenounced(address indexed previousOwner);

    constructor() {
        _totalSupply = 100_000_000_000 * 10 ** decimals; // 100 Miliar ZARO
        _balances[msg.sender] = _totalSupply;
        owner = msg.sender;

        emit Transfer(address(0), msg.sender, _totalSupply);

        // Auto renounce
        emit OwnershipRenounced(owner);
        owner = address(0);
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "Not owner");
        _;
    }

    function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) external view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) external override returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

    function allowance(address _owner, address spender) external view override returns (uint256) {
        return _allowances[_owner][spender];
    }

    function approve(address spender, uint256 amount) external override returns (bool) {
        require(spender != address(0), "Invalid spender");

        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
        require(_allowances[sender][msg.sender] >= amount, "Insufficient allowance");

        _allowances[sender][msg.sender] -= amount;
        _transfer(sender, recipient, amount);

        emit Approval(sender, msg.sender, _allowances[sender][msg.sender]); // Optional, tapi baik untuk tracking
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) external returns (bool) {
        _allowances[msg.sender][spender] += addedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool) {
        require(_allowances[msg.sender][spender] >= subtractedValue, "Decreased allowance below zero");
        _allowances[msg.sender][spender] -= subtractedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }

    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "Invalid sender");
        require(recipient != address(0), "Invalid recipient");
        require(_balances[sender] >= amount, "Insufficient balance");

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

        emit Transfer(sender, recipient, amount);
    }
}

{
  "compilationTarget": {
    "contracts/Zaro.sol": "Zaro"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}