pragma solidity >0.8.0 <0.9.0;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol";


interface IIdleTokenV3_1 is IERC20 {
  // view
  /**
   * IdleToken price calculation, in underlying
   *
   * @return  price in underlying token
   */
  function tokenPrice() external view returns (uint256 price);

  /**
   * @return : underlying token address
   */
  function token() external view returns (address);
  /**
   * Get APR of every ILendingProtocol
   *
   * @return addresses array of token addresses
   * @return aprs array of aprs (ordered in respect to the `addresses` array)
   */
  function getAPRs() external view returns (address[] memory addresses, uint256[] memory aprs);

  // external
  // We should save the amount one has deposited to calc interests

  /**
   * Used to mint IdleTokens, given an underlying amount (eg. DAI).
   * This method triggers a rebalance of the pools if needed
   * NOTE: User should 'approve' _amount of tokens before calling mintIdleToken
   * NOTE 2: this method can be paused
   *
   * @param _amount : amount of underlying token to be lended
   * @param _skipRebalance : flag for skipping rebalance for lower gas price
   * @param _referral : referral address
   * @return mintedTokens : amount of IdleTokens minted
   */
  function mintIdleToken(uint256 _amount, bool _skipRebalance, address _referral) external returns (uint256 mintedTokens);

  /**
   * Here we calc the pool share one can withdraw given the amount of IdleToken they want to burn
   * This method triggers a rebalance of the pools if needed
   * NOTE: If the contract is paused or iToken price has decreased one can still redeem but no rebalance happens.
   * NOTE 2: If iToken price has decresed one should not redeem (but can do it) otherwise he would capitalize the loss.
   *         Ideally one should wait until the black swan event is terminated
   *
   * @param _amount : amount of IdleTokens to be burned
   * @return redeemedTokens : amount of underlying tokens redeemed
   */
  function redeemIdleToken(uint256 _amount) external returns (uint256 redeemedTokens);
  /**
   * Here we calc the pool share one can withdraw given the amount of IdleToken they want to burn
   * and send interest-bearing tokens (eg. cDAI/iDAI) directly to the user.
   * Underlying (eg. DAI) is not redeemed here.
   *
   * @param _amount : amount of IdleTokens to be burned
   */
  function redeemInterestBearingTokens(uint256 _amount) external;

  /**
   * @return : whether has rebalanced or not
   */
  function rebalance() external returns (bool);
  
  function userAvgPrices(address _user) external view returns (uint256 avgPrice);

}