Initial commit

contracts/interfaces/IFlashLoanRouter.sol

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+// 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);
+}
+