// SPDX-License-Identifier: MIT
// -------------------
// Router Version: 4.1
// -------------------
pragma solidity 0.8.13;

// ERC20 Interface
interface iERC20 {
    function balanceOf(address) external view returns (uint256);
    function burn(uint) external;
}
// RUNE Interface
interface iRUNE {
    function transferTo(address, uint) external returns (bool);
}
// ROUTER Interface
interface iROUTER {
    function depositWithExpiry(address, address, uint, string calldata, uint) external;
}

// THORChain_Router is managed by THORChain Vaults
contract THORChain_Router {
    address public RUNE;

    struct Coin {
        address asset;
        uint amount;
    }

    // Vault allowance for each asset
    mapping(address => mapping(address => uint)) private _vaultAllowance;

    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;

    // Emitted for all deposits, the memo distinguishes for swap, add, remove, donate etc
    event Deposit(address indexed to, address indexed asset, uint amount, string memo);

    // Emitted for all outgoing transfers, the vault dictates who sent it, memo used to track.
    event TransferOut(address indexed vault, address indexed to, address asset, uint amount, string memo);

    // Emitted for all outgoing transferAndCalls, the vault dictates who sent it, memo used to track.
    event TransferOutAndCall(address indexed vault, address target, uint amount, address finalAsset, address to, uint256 amountOutMin, string memo);

    // Changes the spend allowance between vaults
    event TransferAllowance(address indexed oldVault, address indexed newVault, address asset, uint amount, string memo);

    // Specifically used to batch send the entire vault assets
    event VaultTransfer(address indexed oldVault, address indexed newVault, Coin[] coins, string memo);

    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        _status = _ENTERED;
        _;
        _status = _NOT_ENTERED;
    }

    constructor(address rune) {
        RUNE = rune;
        _status = _NOT_ENTERED;
    }

    // Deposit with Expiry (preferred)
    function depositWithExpiry(address payable vault, address asset, uint amount, string memory memo, uint expiration) external payable {
        require(block.timestamp < expiration, "THORChain_Router: expired");
        deposit(vault, asset, amount, memo);
    }

    // Deposit an asset with a memo. ETH is forwarded, ERC-20 stays in ROUTER
    function deposit(address payable vault, address asset, uint amount, string memory memo) public payable nonReentrant{
        uint safeAmount;
        if(asset == address(0)){
            safeAmount = msg.value;
            bool success = vault.send(safeAmount);
            require(success);
        } else {
            require(msg.value == 0, "THORChain_Router: unexpected eth");  // protect user from accidentally locking up eth
            if(asset == RUNE) {
                safeAmount = amount;
                iRUNE(RUNE).transferTo(address(this), amount);
                iERC20(RUNE).burn(amount);
            } else {
                safeAmount = safeTransferFrom(asset, amount); // Transfer asset
                _vaultAllowance[vault][asset] += safeAmount; // Credit to chosen vault
            }
        }
        emit Deposit(vault, asset, safeAmount, memo);
    }

    //############################## ALLOWANCE TRANSFERS ##############################

    // Use for "moving" assets between vaults (asgard<>ygg), as well "churning" to a new Asgard
    function transferAllowance(address router, address newVault, address asset, uint amount, string memory memo) external nonReentrant {
        if (router == address(this)){
            _adjustAllowances(newVault, asset, amount);
            emit TransferAllowance(msg.sender, newVault, asset, amount, memo);
        } else {
            _routerDeposit(router, newVault, asset, amount, memo);
        }
    }

    //############################## ASSET TRANSFERS ##############################

    // Any vault calls to transfer any asset to any recipient.
    // Note: Contract recipients of ETH are only given 2300 Gas to complete execution.
    function transferOut(address payable to, address asset, uint amount, string memory memo) public payable nonReentrant {
        uint safeAmount;
        if(asset == address(0)){
            safeAmount = msg.value;
            bool success = to.send(safeAmount); // Send ETH. 
            if (!success) {
                payable(address(msg.sender)).transfer(safeAmount); // For failure, bounce back to vault & continue.
            }
        } else {
            _vaultAllowance[msg.sender][asset] -= amount; // Reduce allowance
            (bool success, bytes memory data) = asset.call(abi.encodeWithSignature("transfer(address,uint256)" , to, amount));
            require(success && (data.length == 0 || abi.decode(data, (bool))));
            safeAmount = amount;
        }
        emit TransferOut(msg.sender, to, asset, safeAmount, memo);
    }

    // Any vault calls to transferAndCall on a target contract that conforms with "swapOut(address,address,uint256)"
    // Example Memo: "~1b3:ETH.0xFinalToken:0xTo:"
    // Aggregator is matched to the last three digits of whitelisted aggregators
    // FinalToken, To, amountOutMin come from originating memo
    // Memo passed in here is the "OUT:HASH" type
    function transferOutAndCall(address payable aggregator, address finalToken, address to, uint256 amountOutMin, string memory memo) public payable nonReentrant {
        uint256 _safeAmount = msg.value;
        (bool erc20Success, ) = aggregator.call{value:_safeAmount}(abi.encodeWithSignature("swapOut(address,address,uint256)", finalToken, to, amountOutMin));
        if (!erc20Success) {
            bool ethSuccess = payable(to).send(_safeAmount); // If can't swap, just send the recipient the ETH
            if (!ethSuccess) {
                payable(address(msg.sender)).transfer(_safeAmount); // For failure, bounce back to vault & continue.
            }
        }
        emit TransferOutAndCall(msg.sender, aggregator, _safeAmount, finalToken, to, amountOutMin, memo);
    }


    //############################## VAULT MANAGEMENT ##############################

    // A vault can call to "return" all assets to an asgard, including ETH. 
    function returnVaultAssets(address router, address payable asgard, Coin[] memory coins, string memory memo) external payable nonReentrant {
        if (router == address(this)){
            for(uint i = 0; i < coins.length; i++){
                _adjustAllowances(asgard, coins[i].asset, coins[i].amount);
            }
            emit VaultTransfer(msg.sender, asgard, coins, memo); // Does not include ETH.           
        } else {
            for(uint i = 0; i < coins.length; i++){
                _routerDeposit(router, asgard, coins[i].asset, coins[i].amount, memo);
            }
        }
        bool success = asgard.send(msg.value);
        require(success);
    }

    //############################## HELPERS ##############################

    function vaultAllowance(address vault, address token) public view returns(uint amount){
        return _vaultAllowance[vault][token];
    }

    // Safe transferFrom in case asset charges transfer fees
    function safeTransferFrom(address _asset, uint _amount) internal returns(uint amount) {
        uint _startBal = iERC20(_asset).balanceOf(address(this));
        (bool success, bytes memory data) = _asset.call(abi.encodeWithSignature("transferFrom(address,address,uint256)", msg.sender, address(this), _amount));
        require(success && (data.length == 0 || abi.decode(data, (bool))));
        return (iERC20(_asset).balanceOf(address(this)) - _startBal);
    }

    // Decrements and Increments Allowances between two vaults
    function _adjustAllowances(address _newVault, address _asset, uint _amount) internal {
        _vaultAllowance[msg.sender][_asset] -= _amount;
        _vaultAllowance[_newVault][_asset] += _amount;
    }

    // Adjust allowance and forwards funds to new router, credits allowance to desired vault
    function _routerDeposit(address _router, address _vault, address _asset, uint _amount, string memory _memo) internal {
        _vaultAllowance[msg.sender][_asset] -= _amount;
        (bool success,) = _asset.call(abi.encodeWithSignature("approve(address,uint256)", _router, _amount)); // Approve to transfer
        require(success);
        iROUTER(_router).depositWithExpiry(_vault, _asset, _amount, _memo, type(uint).max); // Transfer by depositing
    }
}

pragma solidity ^0.4.17;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
    address public owner;

    /**
      * @dev The Ownable constructor sets the original `owner` of the contract to the sender
      * account.
      */
    function Ownable() public {
        owner = msg.sender;
    }

    /**
      * @dev Throws if called by any account other than the owner.
      */
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) public onlyOwner {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }

}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20Basic {
    uint public _totalSupply;
    function totalSupply() public constant returns (uint);
    function balanceOf(address who) public constant returns (uint);
    function transfer(address to, uint value) public;
    event Transfer(address indexed from, address indexed to, uint value);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint);
    function transferFrom(address from, address to, uint value) public;
    function approve(address spender, uint value) public;
    event Approval(address indexed owner, address indexed spender, uint value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is Ownable, ERC20Basic {
    using SafeMath for uint;

    mapping(address => uint) public balances;

    // additional variables for use if transaction fees ever became necessary
    uint public basisPointsRate = 0;
    uint public maximumFee = 0;

    /**
    * @dev Fix for the ERC20 short address attack.
    */
    modifier onlyPayloadSize(uint size) {
        require(!(msg.data.length < size + 4));
        _;
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        uint sendAmount = _value.sub(fee);
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(msg.sender, owner, fee);
        }
        Transfer(msg.sender, _to, sendAmount);
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public constant returns (uint balance) {
        return balances[_owner];
    }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is BasicToken, ERC20 {

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

    uint public constant MAX_UINT = 2**256 - 1;

    /**
    * @dev Transfer tokens from one address to another
    * @param _from address The address which you want to send tokens from
    * @param _to address The address which you want to transfer to
    * @param _value uint the amount of tokens to be transferred
    */
    function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
        // if (_value > _allowance) throw;

        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        if (_allowance < MAX_UINT) {
            allowed[_from][msg.sender] = _allowance.sub(_value);
        }
        uint sendAmount = _value.sub(fee);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(_from, owner, fee);
        }
        Transfer(_from, _to, sendAmount);
    }

    /**
    * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
    * @param _spender The address which will spend the funds.
    * @param _value The amount of tokens to be spent.
    */
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender, 0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));

        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
    }

    /**
    * @dev Function to check the amount of tokens than an owner allowed to a spender.
    * @param _owner address The address which owns the funds.
    * @param _spender address The address which will spend the funds.
    * @return A uint specifying the amount of tokens still available for the spender.
    */
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        return allowed[_owner][_spender];
    }

}


/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}

contract BlackList is Ownable, BasicToken {

    /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
    function getBlackListStatus(address _maker) external constant returns (bool) {
        return isBlackListed[_maker];
    }

    function getOwner() external constant returns (address) {
        return owner;
    }

    mapping (address => bool) public isBlackListed;
    
    function addBlackList (address _evilUser) public onlyOwner {
        isBlackListed[_evilUser] = true;
        AddedBlackList(_evilUser);
    }

    function removeBlackList (address _clearedUser) public onlyOwner {
        isBlackListed[_clearedUser] = false;
        RemovedBlackList(_clearedUser);
    }

    function destroyBlackFunds (address _blackListedUser) public onlyOwner {
        require(isBlackListed[_blackListedUser]);
        uint dirtyFunds = balanceOf(_blackListedUser);
        balances[_blackListedUser] = 0;
        _totalSupply -= dirtyFunds;
        DestroyedBlackFunds(_blackListedUser, dirtyFunds);
    }

    event DestroyedBlackFunds(address _blackListedUser, uint _balance);

    event AddedBlackList(address _user);

    event RemovedBlackList(address _user);

}

contract UpgradedStandardToken is StandardToken{
    // those methods are called by the legacy contract
    // and they must ensure msg.sender to be the contract address
    function transferByLegacy(address from, address to, uint value) public;
    function transferFromByLegacy(address sender, address from, address spender, uint value) public;
    function approveByLegacy(address from, address spender, uint value) public;
}

contract TetherToken is Pausable, StandardToken, BlackList {

    string public name;
    string public symbol;
    uint public decimals;
    address public upgradedAddress;
    bool public deprecated;

    //  The contract can be initialized with a number of tokens
    //  All the tokens are deposited to the owner address
    //
    // @param _balance Initial supply of the contract
    // @param _name Token Name
    // @param _symbol Token symbol
    // @param _decimals Token decimals
    function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
        _totalSupply = _initialSupply;
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        balances[owner] = _initialSupply;
        deprecated = false;
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transfer(address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[msg.sender]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
        } else {
            return super.transfer(_to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[_from]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
        } else {
            return super.transferFrom(_from, _to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function balanceOf(address who) public constant returns (uint) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).balanceOf(who);
        } else {
            return super.balanceOf(who);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
        } else {
            return super.approve(_spender, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        if (deprecated) {
            return StandardToken(upgradedAddress).allowance(_owner, _spender);
        } else {
            return super.allowance(_owner, _spender);
        }
    }

    // deprecate current contract in favour of a new one
    function deprecate(address _upgradedAddress) public onlyOwner {
        deprecated = true;
        upgradedAddress = _upgradedAddress;
        Deprecate(_upgradedAddress);
    }

    // deprecate current contract if favour of a new one
    function totalSupply() public constant returns (uint) {
        if (deprecated) {
            return StandardToken(upgradedAddress).totalSupply();
        } else {
            return _totalSupply;
        }
    }

    // Issue a new amount of tokens
    // these tokens are deposited into the owner address
    //
    // @param _amount Number of tokens to be issued
    function issue(uint amount) public onlyOwner {
        require(_totalSupply + amount > _totalSupply);
        require(balances[owner] + amount > balances[owner]);

        balances[owner] += amount;
        _totalSupply += amount;
        Issue(amount);
    }

    // Redeem tokens.
    // These tokens are withdrawn from the owner address
    // if the balance must be enough to cover the redeem
    // or the call will fail.
    // @param _amount Number of tokens to be issued
    function redeem(uint amount) public onlyOwner {
        require(_totalSupply >= amount);
        require(balances[owner] >= amount);

        _totalSupply -= amount;
        balances[owner] -= amount;
        Redeem(amount);
    }

    function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
        // Ensure transparency by hardcoding limit beyond which fees can never be added
        require(newBasisPoints < 20);
        require(newMaxFee < 50);

        basisPointsRate = newBasisPoints;
        maximumFee = newMaxFee.mul(10**decimals);

        Params(basisPointsRate, maximumFee);
    }

    // Called when new token are issued
    event Issue(uint amount);

    // Called when tokens are redeemed
    event Redeem(uint amount);

    // Called when contract is deprecated
    event Deprecate(address newAddress);

    // Called if contract ever adds fees
    event Params(uint feeBasisPoints, uint maxFee);
}