// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title Types
 * @notice Contains various types used throughout the Optimism contract system.
 */
library Types {
    /**
     * @notice OutputProposal represents a commitment to the L2 state. The timestamp is the L1
     *         timestamp that the output root is posted. This timestamp is used to verify that the
     *         finalization period has passed since the output root was submitted.
     *
     * @custom:field outputRoot    Hash of the L2 output.
     * @custom:field timestamp     Timestamp of the L1 block that the output root was submitted in.
     * @custom:field l2BlockNumber L2 block number that the output corresponds to.
     */
    struct OutputProposal {
        bytes32 outputRoot;
        uint128 timestamp;
        uint128 l2BlockNumber;
    }

    /**
     * @notice Struct representing the elements that are hashed together to generate an output root
     *         which itself represents a snapshot of the L2 state.
     *
     * @custom:field version                  Version of the output root.
     * @custom:field stateRoot                Root of the state trie at the block of this output.
     * @custom:field messagePasserStorageRoot Root of the message passer storage trie.
     * @custom:field latestBlockhash          Hash of the block this output was generated from.
     */
    struct OutputRootProof {
        bytes32 version;
        bytes32 stateRoot;
        bytes32 messagePasserStorageRoot;
        bytes32 latestBlockhash;
    }

    /**
     * @notice Struct representing a deposit transaction (L1 => L2 transaction) created by an end
     *         user (as opposed to a system deposit transaction generated by the system).
     *
     * @custom:field from        Address of the sender of the transaction.
     * @custom:field to          Address of the recipient of the transaction.
     * @custom:field isCreation  True if the transaction is a contract creation.
     * @custom:field value       Value to send to the recipient.
     * @custom:field mint        Amount of ETH to mint.
     * @custom:field gasLimit    Gas limit of the transaction.
     * @custom:field data        Data of the transaction.
     * @custom:field l1BlockHash Hash of the block the transaction was submitted in.
     * @custom:field logIndex    Index of the log in the block the transaction was submitted in.
     */
    struct UserDepositTransaction {
        address from;
        address to;
        bool isCreation;
        uint256 value;
        uint256 mint;
        uint64 gasLimit;
        bytes data;
        bytes32 l1BlockHash;
        uint256 logIndex;
    }

    /**
     * @notice Struct representing a withdrawal transaction.
     *
     * @custom:field nonce    Nonce of the withdrawal transaction
     * @custom:field sender   Address of the sender of the transaction.
     * @custom:field target   Address of the recipient of the transaction.
     * @custom:field value    Value to send to the recipient.
     * @custom:field gasLimit Gas limit of the transaction.
     * @custom:field data     Data of the transaction.
     */
    struct WithdrawalTransaction {
        uint256 nonce;
        address sender;
        address target;
        uint256 value;
        uint256 gasLimit;
        bytes data;
    }
}
