// SPDX-FileCopyrightText: 2024 Lido <info@lido.fi>
// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.24;

import { MerkleProof } from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import { ICSEarlyAdoption } from "./interfaces/ICSEarlyAdoption.sol";

contract CSEarlyAdoption is ICSEarlyAdoption {
    /// @dev Root of the EA members Merkle Tree
    bytes32 public immutable TREE_ROOT;
    /// @dev Id of the bond curve to be assigned for the EA members
    uint256 public immutable CURVE_ID;
    /// @dev Address of the Staking Module using Early Adoption contract
    address public immutable MODULE;

    mapping(address => bool) internal _consumedAddresses;

    event Consumed(address indexed member);

    error InvalidProof();
    error AlreadyConsumed();
    error InvalidTreeRoot();
    error InvalidCurveId();
    error ZeroModuleAddress();
    error SenderIsNotModule();

    constructor(bytes32 treeRoot, uint256 curveId, address module) {
        if (treeRoot == bytes32(0)) revert InvalidTreeRoot();
        if (curveId == 0) revert InvalidCurveId();
        if (module == address(0)) revert ZeroModuleAddress();

        TREE_ROOT = treeRoot;
        CURVE_ID = curveId;
        MODULE = module;
    }

    /// @notice Validate EA eligibility proof and mark it as consumed
    /// @dev Called only by the module
    /// @param member Address to be verified alongside the proof
    /// @param proof Merkle proof of EA eligibility
    function consume(address member, bytes32[] calldata proof) external {
        if (msg.sender != MODULE) revert SenderIsNotModule();
        if (_consumedAddresses[member]) revert AlreadyConsumed();
        if (!verifyProof(member, proof)) revert InvalidProof();
        _consumedAddresses[member] = true;
        emit Consumed(member);
    }

    /// @notice Check if the address has already consumed EA access
    /// @param member Address to check
    function isConsumed(address member) external view returns (bool) {
        return _consumedAddresses[member];
    }

    /// @notice Check is the address is eligible to consume EA access
    /// @param member Address to check
    /// @param proof Merkle proof of EA eligibility
    /// @return Boolean flag if the proof is valid or not
    function verifyProof(
        address member,
        bytes32[] calldata proof
    ) public view returns (bool) {
        return MerkleProof.verifyCalldata(proof, TREE_ROOT, hashLeaf(member));
    }

    /// @notice Get a hash of a leaf in EA Merkle tree
    /// @param member EA member address
    /// @return Hash of the leaf
    /// @dev Double hash the leaf to prevent second preimage attacks
    function hashLeaf(address member) public pure returns (bytes32) {
        return keccak256(bytes.concat(keccak256(abi.encode(member))));
    }
}

// SPDX-FileCopyrightText: 2024 Lido <info@lido.fi>
// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.24;

interface ICSEarlyAdoption {
    function CURVE_ID() external view returns (uint256);

    function TREE_ROOT() external view returns (bytes32);

    function verifyProof(
        address addr,
        bytes32[] calldata proof
    ) external view returns (bool);

    function consume(address sender, bytes32[] calldata proof) external;

    function isConsumed(address sender) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.20;

/**
 * @dev These functions deal with verification of Merkle Tree proofs.
 *
 * The tree and the proofs can be generated using our
 * https://github.com/OpenZeppelin/merkle-tree[JavaScript library].
 * You will find a quickstart guide in the readme.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the Merkle tree could be reinterpreted as a leaf value.
 * OpenZeppelin's JavaScript library generates Merkle trees that are safe
 * against this attack out of the box.
 */
library MerkleProof {
    /**
     *@dev The multiproof provided is not valid.
     */
    error MerkleProofInvalidMultiproof();

    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Calldata version of {verify}
     */
    function verifyCalldata(bytes32[] calldata proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
        return processProofCalldata(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Calldata version of {processProof}
     */
    function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Returns true if the `leaves` can be simultaneously proven to be a part of a Merkle tree defined by
     * `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
     *
     * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
     */
    function multiProofVerify(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProof(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Calldata version of {multiProofVerify}
     *
     * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
     */
    function multiProofVerifyCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProofCalldata(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Returns the root of a tree reconstructed from `leaves` and sibling nodes in `proof`. The reconstruction
     * proceeds by incrementally reconstructing all inner nodes by combining a leaf/inner node with either another
     * leaf/inner node or a proof sibling node, depending on whether each `proofFlags` item is true or false
     * respectively.
     *
     * CAUTION: Not all Merkle trees admit multiproofs. To use multiproofs, it is sufficient to ensure that: 1) the tree
     * is complete (but not necessarily perfect), 2) the leaves to be proven are in the opposite order they are in the
     * tree (i.e., as seen from right to left starting at the deepest layer and continuing at the next layer).
     */
    function processMultiProof(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the Merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 proofLen = proof.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        if (leavesLen + proofLen != totalHashes + 1) {
            revert MerkleProofInvalidMultiproof();
        }

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i]
                ? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
                : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            if (proofPos != proofLen) {
                revert MerkleProofInvalidMultiproof();
            }
            unchecked {
                return hashes[totalHashes - 1];
            }
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    /**
     * @dev Calldata version of {processMultiProof}.
     *
     * CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
     */
    function processMultiProofCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the Merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 proofLen = proof.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        if (leavesLen + proofLen != totalHashes + 1) {
            revert MerkleProofInvalidMultiproof();
        }

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i]
                ? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
                : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            if (proofPos != proofLen) {
                revert MerkleProofInvalidMultiproof();
            }
            unchecked {
                return hashes[totalHashes - 1];
            }
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    /**
     * @dev Sorts the pair (a, b) and hashes the result.
     */
    function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
        return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
    }

    /**
     * @dev Implementation of keccak256(abi.encode(a, b)) that doesn't allocate or expand memory.
     */
    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

{
  "compilationTarget": {
    "src/CSEarlyAdoption.sol": "CSEarlyAdoption"
  },
  "evmVersion": "cancun",
  "libraries": {
    "src/lib/AssetRecovererLib.sol:AssetRecovererLib": "0xa74528edc289b1a597faf83fcff7eff871cc01d9",
    "src/lib/NOAddresses.sol:NOAddresses": "0xf8e5de8baf8ad7c93dcb61d13d00eb3d57131c72",
    "src/lib/QueueLib.sol:QueueLib": "0xd19b40cb5401f1413d014a56529f03b3452f70f9"
  },
  "metadata": {
    "bytecodeHash": "none"
  },
  "optimizer": {
    "enabled": true,
    "runs": 250
  },
  "remappings": [
    ":@openzeppelin/contracts-upgradeable/=node_modules/@openzeppelin/contracts-upgradeable/",
    ":@openzeppelin/contracts/=node_modules/@openzeppelin/contracts/",
    ":ds-test/=node_modules/ds-test/src/",
    ":forge-std/=node_modules/forge-std/src/"
  ]
}