// Copyright (C) 2017, 2018, 2019, 2020 dbrock, rain, mrchico, d-xo

// SPDX-License-Identifier: AGPL-3.0-only

pragma solidity >=0.6.12;

contract NoRevertToken {

// --- ERC20 Data ---

string public constant name = "Token";

string public constant symbol = "TKN";

uint8 public decimals = 18;

uint256 public totalSupply;

mapping (address => uint) public balanceOf;

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

event Approval(address indexed src, address indexed guy, uint wad);

event Transfer(address indexed src, address indexed dst, uint wad);

// --- Init ---

constructor(uint _totalSupply) public {

totalSupply = _totalSupply;

balanceOf[msg.sender] = _totalSupply;

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

}

// --- Token ---

function transfer(address dst, uint wad) external returns (bool) {

return transferFrom(msg.sender, dst, wad);

}

function transferFrom(address src, address dst, uint wad) virtual public returns (bool) {

if (balanceOf[src] < wad) return false; // insufficient src bal

if (balanceOf[dst] >= (type(uint256).max - wad)) return false; // dst bal too high

if (src != msg.sender && allowance[src][msg.sender] != type(uint).max) {

if (allowance[src][msg.sender] < wad) return false; // insufficient allowance

allowance[src][msg.sender] = allowance[src][msg.sender] - wad;

}

balanceOf[src] = balanceOf[src] - wad;

balanceOf[dst] = balanceOf[dst] + wad;

emit Transfer(src, dst, wad);

return true;

}

function approve(address usr, uint wad) virtual external returns (bool) {

allowance[msg.sender][usr] = wad;

emit Approval(msg.sender, usr, wad);

return true;

}

function mint(address usr, uint wad) virtual external {

balanceOf[usr] = balanceOf[usr] + wad;

totalSupply = totalSupply + wad;

emit Transfer(address(0), usr, wad);

}

}