// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity ^0.8.0;

/// @title Honzon Predeploy Contract Interface
/// @author Acala Developers
/// @notice You can use this predeploy contract to call honzon pallet
/// @dev The interface through which solidity contracts will interact with honzon pallet
interface IHonzon {
    /// @notice Adjusted Loan event.
    /// @param sender The sender of the transaction.
    /// @param currencyId The collateral currency id.
    /// @param collateralAdjustment The signed amount,
    /// positive means to deposit collateral currency into CDP,
    /// negative means withdraw collateral currency from CDP.
    /// @param debitAdjustment The signed amount,
    /// positive means to issue some amount of stablecoin to caller according to the debit adjustment,
    /// negative means caller will payback some amount of stablecoin to CDP according to to the debit adjustment.
    event AdjustedLoan(
        address indexed sender,
        address indexed currencyId,
        int128 collateralAdjustment,
        int128 debitAdjustment
    );

    /// @notice Closed loan by DEX event.
    /// @param sender The sender of the transaction.
    /// @param currencyId The collateral currency id.
    event ClosedLoanByDex(address indexed sender, address indexed currencyId);

    /// @notice Adjust CDP position.
    /// @dev It'll emit an {AdjustedLoan} event.
    /// @param currencyId The collateral currency id.
    /// @param collateralAdjustment The signed amount,
    /// positive means to deposit collateral currency into CDP,
    /// negative means withdraw collateral currency from CDP.
    /// @param debitAdjustment The signed amount,
    /// positive means to issue some amount of stablecoin to caller according to the debit adjustment,
    /// negative means caller will payback some amount of stablecoin to CDP according to to the debit adjustment.
    /// @return Returns a boolean value indicating whether the operation succeeded.
    function adjustLoan(
        address currencyId,
        int128 collateralAdjustment,
        int128 debitAdjustment
    ) external returns (bool);

    /// @notice Close CDP position with DEX.
    /// @dev It'll emit an {ClosedLoanByDex} event.
    /// @param currencyId The collateral currency id.
    /// @param maxCollateralAmount The max collateral amount which is used to swap enough stable token to clear debit.
    /// @return Returns a boolean value indicating whether the operation succeeded.
    function closeLoanByDex(
        address currencyId,
        uint256 maxCollateralAmount
    ) external returns (bool);

    /// @notice Get an open CDP position.
    /// @param who The specified user.
    /// @param currencyId The collateral currency id.
    /// @return Returns (collateral_amount, debit_amount).
    function getPosition(
        address who,
        address currencyId
    ) external view returns (uint256, uint256);

    /// @notice Get collateral parameters for a currencyId
    /// @param currencyId The collateral currency id.
    /// @return Returns (params) which is an array with 5 entries in the order that follows:
    /// - [0] `maximum_total_debit_value`: Hardcap of total debit value generated from this collateral.
    /// - [1] `interest_rate_per_sec`: A FixedU128 representing a decimal value. Interest rate of CDP loan per second
    /// - [2] `liquidation_ratio`: A FixedU128 representing a decimal value. Liquidation ratio for this collateral type
    /// - [3] `liquidation_penalty`: A FixedU128 representing a decimal value. Penalty added on for getting liquidated
    /// - [4] `required_collateral_ratio`: A FixedU128 representing a decimal value.
    /// It cannot adjust the position of CDP so that the current collateral ratio is lower than
    /// the required collateral ratio.
    function getCollateralParameters(
        address currencyId
    ) external view returns (uint256[] memory);

    /// @notice Get current collateral ratio for a particular CDP position
    /// @param who The specified user.
    /// @param currencyId The collateral currency id.
    /// @return Returns (current_collateral_ratio), value is FixedU128 with a range of
    /// [0.000000000000000000, 340282366920938463463.374607431768211455]
    function getCurrentCollateralRatio(
        address who,
        address currencyId
    ) external view returns (uint256);

    /// @notice Get exchange rate of debit units to debit value for a currency_id
    /// @param currencyId The collateral currency id.
    /// @return Returns (exchange_rate), value is FixedU128 with a range of
    /// [0.000000000000000000, 340282366920938463463.374607431768211455]
    function getDebitExchangeRate(
        address currencyId
    ) external view returns (uint256);
}