// SPDX-License-Identifier: MIT
pragma solidity 0.8.23;

/// @dev Canonical SP1 verifier / SP1VerifierGateway ABI: verifyProof RETURNS
///      NOTHING and REVERTS on an invalid proof. On chain 2800 the deployed
///      SP1VerifierGateway is 0x9ca479C8c52C0EbB4599319a36a5a017BCC70628 and the
///      SP1 Groth16 route is selected by the proof's leading 4-byte selector
///      0x4388a21c (SP1 v6 groth16), exactly as AereRollupValidity uses it.
interface ISp1Verifier {
    function verifyProof(
        bytes32 programVKey,
        bytes calldata publicValues,
        bytes calldata proof
    ) external view;
}

/**
 * @title AereEVMValidity - on-chain anchor for REAL FULL-EVM validity proofs of
 *        live chain-2800 blocks.
 *
 * @notice Verifies SP1 zkVM Groth16 proofs that a REAL AERE mainnet (chain 2800,
 *         QBFT / Besu) block was re-executed with revm INSIDE the zkVM and that
 *         the recomputed post-state root equals the `header.stateRoot` carried in
 *         the proof's public values. The guest (bin/aere-client) runs the
 *         SP1-patched reth 1.9.3 / revm stack over the block's transactions against
 *         the parent-block pre-state (account + storage MPT proofs gathered by the
 *         host from `eth_getProof`), re-roots the sparse trie, and only produces a
 *         valid proof when computed stateRoot == header.stateRoot.
 *
 *         BINDING CAVEAT (READ THIS): this V1 anchor attests a SELF-CONSISTENT
 *         execution, NOT that the recorded block is the CANONICAL chain-2800 block
 *         at that height. The public values carry no blockHash/parentHash and this
 *         contract performs no blockhash() check, so a genuine SP1 proof of a
 *         FABRICATED execution can be recorded here, and first-write-wins dedup lets
 *         a slot be squatted. Do NOT treat a V1 record as canonical. Canonical
 *         binding (committed blockHash + on-chain blockhash()/EIP-2935 check + batch
 *         continuity) lands in AereEVMValidityV2 / AereEVMValidityBatchV2.
 *
 *         Unlike AereRollupValidity (which proves AERE's BOUNDED toy-VM executor:
 *         Transfer/Sweep/Increment/AmmSwap), this contract anchors proofs of
 *         ARBITRARY EVM bytecode execution: full opcode set, call frames,
 *         SLOAD/SSTORE, LOG, EIP-1559 base-fee burn + priority-to-coinbase, and
 *         the Cancun/Prague/Osaka system calls, all of which affect the proven
 *         state root.
 *
 *         PROGRAM BINDING: PROGRAM_VKEY is the SP1 verification key of the exact
 *         guest ELF that performs revm-in-zkVM execution + witness re-root.
 *         Binding the vkey binds the exact prover program.
 *
 *         PUBLIC-VALUES CONVENTION (exactly 224 bytes = 7 x 32):
 *           abi.encode(
 *             uint256 chainId,        // must equal block.chainid (2800)
 *             uint256 blockNumber,    // the proven chain-2800 block height
 *             bytes32 prevStateRoot,  // parent block state root (pre-state anchor,
 *                                     //   NOT cross-checked on-chain in V1)
 *             bytes32 postStateRoot,  // self-consistent post-execution state root
 *             bytes32 txRoot,         // header.transactionsRoot (binds the txs)
 *             uint256 gasUsed,        // total gas used by the block
 *             uint256 numTxns         // number of transactions executed
 *           )
 *
 *         IMMUTABILITY / TRUST: SP1_VERIFIER and PROGRAM_VKEY are fixed at deploy.
 *         There is NO owner and NO admin: recording is permissionless. Soundness
 *         rests entirely on the SP1 Groth16 proof: a record can only be written
 *         for a (blockNumber, prevStateRoot, postStateRoot) triple that the zk
 *         proof establishes for PROGRAM_VKEY.
 *
 * ===========================================================================
 * HONEST SCOPE - READ THIS.
 * ===========================================================================
 *   This proves REAL EVM execution of a SMALL live chain-2800 block (a handful
 *   of transactions). It is a legitimate real-EVM validity PROOF-OF-APPROACH.
 *   It is NOT yet a full-throughput production rollup: it does not prove a large
 *   batch, and it records isolated proven blocks rather than a continuous
 *   sequencer chain. No code, UI or claim built on it should imply otherwise.
 * ===========================================================================
 */
contract AereEVMValidity {

    /// @notice SP1 verifier gateway (routes to the Groth16 verifier by selector).
    address public immutable SP1_VERIFIER;

    /// @notice SP1 vkey binding the exact revm-in-zkVM guest ELF.
    bytes32 public immutable PROGRAM_VKEY;

    /// @notice Number of proven blocks recorded.
    uint256 public provenCount;

    struct ProvenBlock {
        uint64  blockNumber;
        bytes32 prevStateRoot;
        bytes32 postStateRoot;
        bytes32 txRoot;
        uint64  gasUsed;
        uint32  numTxns;
        uint64  at;            // block timestamp when the proof verified
        address prover;        // who submitted it
    }

    /// @notice recordId (0-based) => proven block record.
    mapping(uint256 => ProvenBlock) public records;

    /// @notice chain-2800 blockNumber => 1-based recordId (0 == not proven).
    mapping(uint256 => uint256) public blockToRecord;

    /// @notice The most recently proven post-state root (informational tip).
    bytes32 public latestPostRoot;

    /* --------------------------------- events ------------------------------- */

    event BlockProven(
        uint256 indexed recordId,
        uint256 indexed blockNumber,
        bytes32 prevStateRoot,
        bytes32 postStateRoot,
        bytes32 txRoot,
        uint256 gasUsed,
        uint256 numTxns,
        address prover,
        uint256 at
    );

    /* --------------------------------- errors ------------------------------- */

    error InvalidProof();
    error BadPublicValuesLength(uint256 got);
    error WrongChain(uint256 inProof, uint256 onChain);
    error AlreadyProven(uint256 blockNumber, uint256 recordId);
    error ZeroAddress();
    error ZeroVKey();

    /* ----------------------------- constructor ------------------------------ */

    constructor(address sp1Verifier, bytes32 programVKey) {
        if (sp1Verifier == address(0)) revert ZeroAddress();
        if (programVKey == bytes32(0)) revert ZeroVKey();
        SP1_VERIFIER = sp1Verifier;
        PROGRAM_VKEY = programVKey;
    }

    /* ------------------------------ record block ---------------------------- */

    /// @notice Verify a full-EVM validity proof for a chain-2800 block and, on
    ///         success, record it. Permissionless. Reverts if the proof is not
    ///         valid for PROGRAM_VKEY, if the proof is for a different chain, or
    ///         if that block number was already recorded.
    /// @param publicValues abi.encode(chainId, blockNumber, prevStateRoot,
    ///                     postStateRoot, txRoot, gasUsed, numTxns), 224 bytes.
    /// @param proof        SP1 Groth16 proof bytes (leading selector 0x4388a21c).
    /// @return recordId    the 0-based id of the recorded proven block.
    function recordBlock(
        bytes calldata publicValues,
        bytes calldata proof
    ) external returns (uint256 recordId) {
        // 7 x 32 = 224 bytes.
        if (publicValues.length != 224) revert BadPublicValuesLength(publicValues.length);

        // 1) zk proof: reverts if the proof is not valid for PROGRAM_VKEY.
        try ISp1Verifier(SP1_VERIFIER).verifyProof(PROGRAM_VKEY, publicValues, proof) {
            // verified - did not revert
        } catch {
            revert InvalidProof();
        }

        (
            uint256 chainId,
            uint256 blockNumber,
            bytes32 prevStateRoot,
            bytes32 postStateRoot,
            bytes32 txRoot,
            uint256 gasUsed,
            uint256 numTxns
        ) = abi.decode(
            publicValues,
            (uint256, uint256, bytes32, bytes32, bytes32, uint256, uint256)
        );

        // 2) bind to this chain.
        if (chainId != block.chainid) revert WrongChain(chainId, block.chainid);

        // 3) one record per block number.
        uint256 existing = blockToRecord[blockNumber];
        if (existing != 0) revert AlreadyProven(blockNumber, existing - 1);

        // 4) record the proven block.
        recordId = provenCount;
        records[recordId] = ProvenBlock({
            blockNumber: uint64(blockNumber),
            prevStateRoot: prevStateRoot,
            postStateRoot: postStateRoot,
            txRoot: txRoot,
            gasUsed: uint64(gasUsed),
            numTxns: uint32(numTxns),
            at: uint64(block.timestamp),
            prover: msg.sender
        });
        blockToRecord[blockNumber] = recordId + 1; // 1-based so 0 means "unseen"
        latestPostRoot = postStateRoot;
        provenCount = recordId + 1;

        emit BlockProven(
            recordId, blockNumber, prevStateRoot, postStateRoot,
            txRoot, gasUsed, numTxns, msg.sender, block.timestamp
        );
    }

    /* ----------------------------------- views ------------------------------ */

    /// @notice Stateless verification: reverts if the proof is invalid for
    ///         PROGRAM_VKEY, otherwise returns the decoded fields. Records nothing.
    function verify(
        bytes calldata publicValues,
        bytes calldata proof
    )
        external
        view
        returns (
            uint256 blockNumber,
            bytes32 prevStateRoot,
            bytes32 postStateRoot,
            bytes32 txRoot,
            uint256 gasUsed,
            uint256 numTxns
        )
    {
        if (publicValues.length != 224) revert BadPublicValuesLength(publicValues.length);
        ISp1Verifier(SP1_VERIFIER).verifyProof(PROGRAM_VKEY, publicValues, proof);
        (, blockNumber, prevStateRoot, postStateRoot, txRoot, gasUsed, numTxns) = abi.decode(
            publicValues,
            (uint256, uint256, bytes32, bytes32, bytes32, uint256, uint256)
        );
    }

    /// @notice Convenience accessor for a recorded proven block.
    function getRecord(uint256 recordId)
        external
        view
        returns (
            uint64 blockNumber,
            bytes32 prevStateRoot,
            bytes32 postStateRoot,
            bytes32 txRoot,
            uint64 gasUsed,
            uint32 numTxns,
            uint64 at,
            address prover
        )
    {
        ProvenBlock memory r = records[recordId];
        return (
            r.blockNumber, r.prevStateRoot, r.postStateRoot, r.txRoot,
            r.gasUsed, r.numTxns, r.at, r.prover
        );
    }
}