// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

/**
 * @title IVault
 * @notice Interface for DBIS Institutional Vault
 * @dev Vault represents a leveraged position with collateral and debt tracking
 */
interface IVault {
    /**
     * @notice Emitted when a position snapshot is taken
     * @param collateralBefore Previous collateral amount
     * @param debtBefore Previous debt amount
     * @param collateralAfter New collateral amount
     * @param debtAfter New debt amount
     * @param healthFactorBefore Previous health factor (scaled by 1e18)
     * @param healthFactorAfter New health factor (scaled by 1e18)
     */
    event PositionSnapshot(
        uint256 collateralBefore,
        uint256 debtBefore,
        uint256 collateralAfter,
        uint256 debtAfter,
        uint256 healthFactorBefore,
        uint256 healthFactorAfter
    );

    /**
     * @notice Emitted when collateral is added to the position
     * @param asset Asset address
     * @param amount Amount added
     */
    event CollateralAdded(address indexed asset, uint256 amount);

    /**
     * @notice Emitted when debt is repaid
     * @param asset Asset address
     * @param amount Amount repaid
     */
    event DebtRepaid(address indexed asset, uint256 amount);

    /**
     * @notice Get total collateral value in USD (scaled by 1e8)
     */
    function getTotalCollateralValue() external view returns (uint256);

    /**
     * @notice Get total debt value in USD (scaled by 1e8)
     */
    function getTotalDebtValue() external view returns (uint256);

    /**
     * @notice Get current health factor (scaled by 1e18)
     */
    function getHealthFactor() external view returns (uint256);

    /**
     * @notice Get current LTV (Loan-to-Value ratio, scaled by 1e18)
     */
    function getLTV() external view returns (uint256);

    /**
     * @notice Record addition of collateral
     * @param asset Asset address
     * @param amount Amount added
     */
    function recordCollateralAdded(address asset, uint256 amount) external;

    /**
     * @notice Record repayment of debt
     * @param asset Asset address
     * @param amount Amount repaid
     */
    function recordDebtRepaid(address asset, uint256 amount) external;

    /**
     * @notice Take a position snapshot for invariant checking
     * @return collateralBefore Previous collateral value
     * @return debtBefore Previous debt value
     * @return healthFactorBefore Previous health factor
     */
    function snapshotPosition()
        external
        returns (
            uint256 collateralBefore,
            uint256 debtBefore,
            uint256 healthFactorBefore
        );

    /**
     * @notice Verify position improved (invariant check)
     * @param collateralBefore Previous collateral value
     * @param debtBefore Previous debt value
     * @param healthFactorBefore Previous health factor
     * @return success True if position improved
     */
    function verifyPositionImproved(
        uint256 collateralBefore,
        uint256 debtBefore,
        uint256 healthFactorBefore
    ) external view returns (bool success);
}