// SPDX-License-Identifier: MIT

pragma solidity 0.8.15;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

  /**
   * @dev Moves `amount` tokens from the caller's account to `recipient`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address recipient, uint256 amount) external returns (bool);

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender) external view returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `sender` to `recipient` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) external returns (bool);

  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.15;

import "../../interface/IERC20.sol";

contract LizardUsdtStg is IERC20 {

  string public constant symbol = "slzUSDT";
  string public constant name = "SolidLizard synthetic USDT";
  uint8 public constant decimals = 6;
  uint public override totalSupply = 0;

  mapping(address => uint) public override balanceOf;
  mapping(address => mapping(address => uint)) public override allowance;

  address public minter;

  constructor() {
    minter = msg.sender;
  }

  // No checks as its meant to be once off to set minting rights to Minter
  function setMinter(address _minter) external {
    require(msg.sender == minter, "LIZARD: Not minter");
    minter = _minter;
  }

  function approve(address _spender, uint _value) external override returns (bool) {
    require(_spender != address(0), "LIZARD: Approve to the zero address");
    allowance[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  function _mint(address _to, uint _amount) internal returns (bool) {
    require(_to != address(0), "LIZARD: Mint to the zero address");
    balanceOf[_to] += _amount;
    totalSupply += _amount;
    emit Transfer(address(0x0), _to, _amount);
    return true;
  }

  function _burn(address _from, uint256 _amount) internal returns (bool) {
    require(_from != address(0), "LIZARD: burn from the zero address");
    uint fromBalance = balanceOf[_from];
    require(_amount <= fromBalance, "LIZARD: burn amount exceeds balance");
    unchecked {
        balanceOf[_from] = fromBalance - _amount;
        totalSupply = totalSupply - _amount;
    }
        
    emit Transfer(_from, address(0x0), _amount);
    return true;
  }

  function _transfer(address _from, address _to, uint _value) internal returns (bool) {
    require(_to != address(0), "LIZARD: Transfer to the zero address");

    uint fromBalance = balanceOf[_from];
    require(fromBalance >= _value, "LIZARD: Transfer amount exceeds balance");
  unchecked {
    balanceOf[_from] = fromBalance - _value;
  }

    balanceOf[_to] += _value;
    emit Transfer(_from, _to, _value);
    return true;
  }

  function transfer(address _to, uint _value) external override returns (bool) {
    return _transfer(msg.sender, _to, _value);
  }

  function transferFrom(address _from, address _to, uint _value) external override returns (bool) {
    address spender = msg.sender;
    uint spenderAllowance = allowance[_from][spender];
    if (spenderAllowance != type(uint).max) {
      require(spenderAllowance >= _value, "LIZARD: Insufficient allowance");
    unchecked {
      uint newAllowance = spenderAllowance - _value;
      allowance[_from][spender] = newAllowance;
      emit Approval(_from, spender, newAllowance);
    }
    }
    return _transfer(_from, _to, _value);
  }

  function mint(address account, uint amount) external returns (bool) {
    require(msg.sender == minter, "LIZARD: Not minter");
    return _mint(account, amount);
  }

  function burn(address account, uint amount) external returns (bool) {
    require(msg.sender == minter, "LIZARD: Not minter");
    return _burn(account, amount);
  }
}

{
  "compilationTarget": {
    "contracts/base/token/LizardUsdtStg.sol": "LizardUsdtStg"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}