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

/**
 * @title IFlashLoanRouter
 * @notice Interface for multi-provider flash loan router
 * @dev Aggregates flash loans from Aave, Balancer, Uniswap, DAI flash mint
 */
interface IFlashLoanRouter {
    enum FlashLoanProvider {
        AAVE,
        BALANCER,
        UNISWAP,
        DAI_FLASH
    }

    /**
     * @notice Flash loan parameters
     * @param asset Asset to borrow
     * @param amount Amount to borrow
     * @param provider Provider to use (or AUTO for liquidity-weighted)
     */
    struct FlashLoanParams {
        address asset;
        uint256 amount;
        FlashLoanProvider provider;
    }

    /**
     * @notice Emitted when flash loan is initiated
     * @param asset Asset borrowed
     * @param amount Amount borrowed
     * @param provider Provider used
     */
    event FlashLoanInitiated(
        address indexed asset,
        uint256 amount,
        FlashLoanProvider provider
    );

    /**
     * @notice Emitted when flash loan is repaid
     * @param asset Asset repaid
     * @param amount Amount repaid (principal + fee)
     */
    event FlashLoanRepaid(address indexed asset, uint256 amount);

    /**
     * @notice Execute a flash loan with callback
     * @param params Flash loan parameters
     * @param callbackData Data to pass to callback
     */
    function flashLoan(
        FlashLoanParams memory params,
        bytes memory callbackData
    ) external;

    /**
     * @notice Execute multi-asset flash loan
     * @param params Array of flash loan parameters
     * @param callbackData Data to pass to callback
     */
    function flashLoanBatch(
        FlashLoanParams[] memory params,
        bytes memory callbackData
    ) external;

    /**
     * @notice Get available liquidity for an asset from a provider
     * @param asset Asset address
     * @param provider Provider to check
     * @return available Available liquidity
     */
    function getAvailableLiquidity(
        address asset,
        FlashLoanProvider provider
    ) external view returns (uint256 available);

    /**
     * @notice Get fee for flash loan from a provider
     * @param asset Asset address
     * @param amount Amount to borrow
     * @param provider Provider to check
     * @return fee Fee amount
     */
    function getFlashLoanFee(
        address asset,
        uint256 amount,
        FlashLoanProvider provider
    ) external view returns (uint256 fee);

    /**
     * @notice Callback function executed during flash loan
     * @param asset Asset borrowed
     * @param amount Amount borrowed
     * @param fee Fee for the flash loan
     * @param callbackData Data passed from caller
     */
    function onFlashLoan(
        address asset,
        uint256 amount,
        uint256 fee,
        bytes calldata callbackData
    ) external returns (bytes32);
}