// SPDX-License-Identifier: MIT
// OpenZeppelin Confidential Contracts (last updated v0.4.0) (interfaces/IERC7984ERC20Wrapper.sol)

pragma solidity ^0.8.24;

import {externalEuint64, euint64} from "@fhevm/solidity/lib/FHE.sol";
import {IERC7984} from "./IERC7984.sol";

/// @dev Interface for ERC7984ERC20Wrapper contract.
interface IERC7984ERC20Wrapper is IERC7984 {
    /// @dev Emitted when an unwrap request is made for a given `receiver`, `unwrapRequestId`, and `amount`.
    event UnwrapRequested(address indexed receiver, bytes32 indexed unwrapRequestId, euint64 amount);

    /// @dev Emitted when an unwrap request is finalized for a given `receiver`, `unwrapRequestId`, `encryptedAmount`, and `cleartextAmount`.
    event UnwrapFinalized(
        address indexed receiver,
        bytes32 indexed unwrapRequestId,
        euint64 encryptedAmount,
        uint64 cleartextAmount
    );

    /**
     * @dev Wraps `amount` of the underlying token into a confidential token and sends it to `to`.
     *
     * Returns amount of wrapped token sent.
     */
    function wrap(address to, uint256 amount) external returns (euint64);

    /**
     * @dev Unwraps tokens from `from` and sends the underlying tokens to `to`. The caller must be `from`
     * or be an approved operator for `from`.
     *
     * Returns the unwrap request id.
     *
     * NOTE: The returned unwrap request id must never be zero.
     */
    function unwrap(
        address from,
        address to,
        externalEuint64 encryptedAmount,
        bytes calldata inputProof
    ) external returns (bytes32);

    /// @dev Returns the address of the underlying ERC-20 token that is being wrapped.
    function underlying() external view returns (address);

    /// @dev Finalizes an unwrap request identified by `unwrapRequestId` with the given `unwrapAmountCleartext` and `decryptionProof`.
    function finalizeUnwrap(
        bytes32 unwrapRequestId,
        uint64 unwrapAmountCleartext,
        bytes calldata decryptionProof
    ) external;

    /**
     * @dev Returns the rate at which the underlying token is converted to the wrapped token.
     * For example, if the `rate` is 1000, then 1000 units of the underlying token equal 1 unit of the wrapped token.
     */
    function rate() external view returns (uint256);

    /// @dev Returns the amount of wrapper tokens that were unwrapped for a given `unwrapRequestId`.
    function unwrapAmount(bytes32 unwrapRequestId) external view returns (euint64);
}