// SPDX-License-Identifier: MIT
// Gearbox Protocol. Generalized leverage for DeFi protocols
// (c) Gearbox Holdings, 2022
pragma solidity ^0.8.10;

import { ICreditFilter } from "./ICreditFilter.sol";

struct Exchange {
    address[] path;
    uint256 amountOutMin;
}

/// @title Credit Manager interface
/// @notice It encapsulates business logic for managing credit accounts
///
/// More info: https://dev.gearbox.fi/developers/credit/credit_manager
interface ICreditManager {
    // Emits each time when the credit account is opened
    event OpenCreditAccount(
        address indexed sender,
        address indexed onBehalfOf,
        address indexed creditAccount,
        uint256 amount,
        uint256 borrowAmount,
        uint256 referralCode
    );

    // Emits each time when the credit account is closed
    event CloseCreditAccount(
        address indexed owner,
        address indexed to,
        uint256 remainingFunds
    );

    // Emits each time when the credit account is liquidated
    event LiquidateCreditAccount(
        address indexed owner,
        address indexed liquidator,
        uint256 remainingFunds
    );

    // Emits each time when borrower increases borrowed amount
    event IncreaseBorrowedAmount(address indexed borrower, uint256 amount);

    // Emits each time when borrower adds collateral
    event AddCollateral(
        address indexed onBehalfOf,
        address indexed token,
        uint256 value
    );

    // Emits each time when the credit account is repaid
    event RepayCreditAccount(address indexed owner, address indexed to);

    // Emit each time when financial order is executed
    event ExecuteOrder(address indexed borrower, address indexed target);

    // Emits each time when new fees are set
    event NewParameters(
        uint256 minAmount,
        uint256 maxAmount,
        uint256 maxLeverage,
        uint256 feeInterest,
        uint256 feeLiquidation,
        uint256 liquidationDiscount
    );

    event TransferAccount(address indexed oldOwner, address indexed newOwner);

    //
    // CREDIT ACCOUNT MANAGEMENT
    //

    /**
     * @dev Opens credit account and provides credit funds.
     * - Opens credit account (take it from account factory)
     * - Transfers trader /farmers initial funds to credit account
     * - Transfers borrowed leveraged amount from pool (= amount x leverageFactor) calling lendCreditAccount() on connected Pool contract.
     * - Emits OpenCreditAccount event
     * Function reverts if user has already opened position
     *
     * More info: https://dev.gearbox.fi/developers/credit/credit_manager#open-credit-account
     *
     * @param amount Borrowers own funds
     * @param onBehalfOf The address that will receive the aTokens, same as msg.sender if the user
     *   wants to receive them on his own wallet, or a different address if the beneficiary of aTokens
     *   is a different wallet
     * @param leverageFactor Multiplier to borrowers own funds
     * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
     *   0 if the action is executed directly by the user, without any middle-man
     */
    function openCreditAccount(
        uint256 amount,
        address onBehalfOf,
        uint256 leverageFactor,
        uint256 referralCode
    ) external;

    /**
     * @dev Closes credit account
     * - Swaps all assets to underlying one using default swap protocol
     * - Pays borrowed amount + interest accrued + fees back to the pool by calling repayCreditAccount
     * - Transfers remaining funds to the trader / farmer
     * - Closes the credit account and return it to account factory
     * - Emits CloseCreditAccount event
     *
     * More info: https://dev.gearbox.fi/developers/credit/credit_manager#close-credit-account
     *
     * @param to Address to send remaining funds
     * @param paths Exchange type data which provides paths + amountMinOut
     */
    function closeCreditAccount(address to, Exchange[] calldata paths) external;

    /**
     * @dev Liquidates credit account
     * - Transfers discounted total credit account value from liquidators account
     * - Pays borrowed funds + interest + fees back to pool, than transfers remaining funds to credit account owner
     * - Transfer all assets from credit account to liquidator ("to") account
     * - Returns credit account to factory
     * - Emits LiquidateCreditAccount event
     *
     * More info: https://dev.gearbox.fi/developers/credit/credit_manager#liquidate-credit-account
     *
     * @param borrower Borrower address
     * @param to Address to transfer all assets from credit account
     * @param force If true, use transfer function for transferring tokens instead of safeTransfer
     */
    function liquidateCreditAccount(
        address borrower,
        address to,
        bool force
    ) external;

    /// @dev Repays credit account
    /// More info: https://dev.gearbox.fi/developers/credit/credit_manager#repay-credit-account
    ///
    /// @param to Address to send credit account assets
    function repayCreditAccount(address to) external;

    /// @dev Repays credit account with ETH. Restricted to be called by WETH Gateway only
    ///
    /// @param borrower Address of borrower
    /// @param to Address to send credit account assets
    function repayCreditAccountETH(address borrower, address to)
        external
        returns (uint256);

    /// @dev Increases borrowed amount by transferring additional funds from
    /// the pool if after that HealthFactor > minHealth
    /// More info: https://dev.gearbox.fi/developers/credit/credit_manager#increase-borrowed-amount
    ///
    /// @param amount Amount to increase borrowed amount
    function increaseBorrowedAmount(uint256 amount) external;

    /// @dev Adds collateral to borrower's credit account
    /// @param onBehalfOf Address of borrower to add funds
    /// @param token Token address
    /// @param amount Amount to add
    function addCollateral(
        address onBehalfOf,
        address token,
        uint256 amount
    ) external;

    /// @dev Returns true if the borrower has opened a credit account
    /// @param borrower Borrower account
    function hasOpenedCreditAccount(address borrower)
        external
        view
        returns (bool);

    /// @dev Calculates Repay amount = borrow amount + interest accrued + fee
    ///
    /// More info: https://dev.gearbox.fi/developers/credit/economy#repay
    ///           https://dev.gearbox.fi/developers/credit/economy#liquidate
    ///
    /// @param borrower Borrower address
    /// @param isLiquidated True if calculated repay amount for liquidator
    function calcRepayAmount(address borrower, bool isLiquidated)
        external
        view
        returns (uint256);

    /// @dev Returns minimal amount for open credit account
    function minAmount() external view returns (uint256);

    /// @dev Returns maximum amount for open credit account
    function maxAmount() external view returns (uint256);

    /// @dev Returns maximum leveraged factor allowed for this pool
    function maxLeverageFactor() external view returns (uint256);

    /// @dev Returns underlying token address
    function underlyingToken() external view returns (address);

    /// @dev Returns address of connected pool
    function poolService() external view returns (address);

    /// @dev Returns address of CreditFilter
    function creditFilter() external view returns (ICreditFilter);

    /// @dev Returns address of CreditFilter
    function creditAccounts(address borrower) external view returns (address);

    /// @dev Executes filtered order on credit account which is connected with particular borrowers
    /// @param borrower Borrower address
    /// @param target Target smart-contract
    /// @param data Call data for call
    function executeOrder(
        address borrower,
        address target,
        bytes memory data
    ) external returns (bytes memory);

    /// @dev Approves token for msg.sender's credit account
    function approve(address targetContract, address token) external;

    /// @dev Approve tokens for credit accounts. Restricted for adapters only
    function provideCreditAccountAllowance(
        address creditAccount,
        address toContract,
        address token
    ) external;

    function transferAccountOwnership(address newOwner) external;

    /// @dev Returns address of borrower's credit account and reverts of borrower has no one.
    /// @param borrower Borrower address
    function getCreditAccountOrRevert(address borrower)
        external
        view
        returns (address);

    //    function feeSuccess() external view returns (uint256);

    function feeInterest() external view returns (uint256);

    function feeLiquidation() external view returns (uint256);

    function liquidationDiscount() external view returns (uint256);

    function minHealthFactor() external view returns (uint256);

    function defaultSwapContract() external view returns (address);

    function _calcClosePayments(
        address creditAccount,
        uint256 totalValue,
        bool isLiquidated
    )
        external
        view
        returns (
            uint256 _borrowedAmount,
            uint256 amountToPool,
            uint256 remainingFunds,
            uint256 profit,
            uint256 loss
        );
}