// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Semver } from "../universal/Semver.sol";

/// @custom:proxied
/// @custom:predeploy 0x4200000000000000000000000000000000000015
/// @title L1Block
/// @notice The L1Block predeploy gives users access to information about the last known L1 block.
///         Values within this contract are updated once per epoch (every L1 block) and can only be
///         set by the "depositor" account, a special system address. Depositor account transactions
///         are created by the protocol whenever we move to a new epoch.
contract L1Block is Semver {
    /// @notice Address of the special depositor account.
    address public constant DEPOSITOR_ACCOUNT = 0xDeaDDEaDDeAdDeAdDEAdDEaddeAddEAdDEAd0001;

    /// @notice The latest L1 block number known by the L2 system.
    uint64 public number;

    /// @notice The latest L1 timestamp known by the L2 system.
    uint64 public timestamp;

    /// @notice The latest L1 basefee.
    uint256 public basefee;

    /// @notice The latest L1 blockhash.
    bytes32 public hash;

    /// @notice The number of L2 blocks in the same epoch.
    uint64 public sequenceNumber;

    /// @notice The versioned hash to authenticate the batcher by.
    bytes32 public batcherHash;

    /// @notice The overhead value applied to the L1 portion of the transaction fee.
    uint256 public l1FeeOverhead;

    /// @notice The scalar value applied to the L1 portion of the transaction fee.
    uint256 public l1FeeScalar;

    /// @custom:semver 1.0.2
    /// @notice Constructs the L1Block contract.
    constructor() Semver(1, 0, 2) { }

    /// @notice Updates the L1 block values.
    /// @param _number         L1 blocknumber.
    /// @param _timestamp      L1 timestamp.
    /// @param _basefee        L1 basefee.
    /// @param _hash           L1 blockhash.
    /// @param _sequenceNumber Number of L2 blocks since epoch start.
    /// @param _batcherHash    Versioned hash to authenticate batcher by.
    /// @param _l1FeeOverhead  L1 fee overhead.
    /// @param _l1FeeScalar    L1 fee scalar.
    function setL1BlockValues(
        uint64 _number,
        uint64 _timestamp,
        uint256 _basefee,
        bytes32 _hash,
        uint64 _sequenceNumber,
        bytes32 _batcherHash,
        uint256 _l1FeeOverhead,
        uint256 _l1FeeScalar
    )
        external
    {
        require(msg.sender == DEPOSITOR_ACCOUNT, "L1Block: only the depositor account can set L1 block values");

        number = _number;
        timestamp = _timestamp;
        basefee = _basefee;
        hash = _hash;
        sequenceNumber = _sequenceNumber;
        batcherHash = _batcherHash;
        l1FeeOverhead = _l1FeeOverhead;
        l1FeeScalar = _l1FeeScalar;
    }
}
