pragma solidity >=0.6.0;

interface ILiquidityPool {

event AddSymbol(string optSymbol);

event RemoveSymbol(string optSymbol);

event Buy(address indexed token, address indexed buyer, uint price, uint volume);

event Sell(address indexed token, address indexed seller, uint price, uint volume);

function maturity() external view returns (uint);

function yield(uint dt) external view returns (uint y);

function depositTokens(

address to,

address token,

uint value,

uint deadline,

uint8 v,

bytes32 r,

bytes32 s

) external;

function depositTokens(address to, address token, uint value) external;

function withdraw(uint amount) external;

function listSymbols() external view returns (string memory available);

function queryBuy(string calldata optSymbol) external view returns (uint price, uint volume);

function querySell(string calldata optSymbol) external view returns (uint price, uint volume);

function buy(

string calldata optSymbol,

uint price,

uint volume,

address token,

uint maxValue,

uint deadline,

uint8 v,

bytes32 r,

bytes32 s

)

external

returns (address addr);

function buy(string calldata optSymbol, uint price, uint volume, address token)

external

returns (address addr);

function sell(

string calldata optSymbol,

uint price,

uint volume,

uint deadline,

uint8 v,

bytes32 r,

bytes32 s

)

external;

function sell(string calldata optSymbol, uint price, uint volume) external;

}