// Syscall selectors.

const CALL_CONTRACT_SELECTOR = 'CallContract';
const DEPLOY_SELECTOR = 'Deploy';
const EMIT_EVENT_SELECTOR = 'EmitEvent';
const GET_EXECUTION_INFO_SELECTOR = 'GetExecutionInfo';
const LIBRARY_CALL_SELECTOR = 'LibraryCall';
const REPLACE_CLASS_SELECTOR = 'ReplaceClass';
const SEND_MESSAGE_TO_L1_SELECTOR = 'SendMessageToL1';
const STORAGE_READ_SELECTOR = 'StorageRead';
const STORAGE_WRITE_SELECTOR = 'StorageWrite';

// Syscall structs.

struct ExecutionInfo {
    block_info: BlockInfo*,
    tx_info: TxInfo*,

    // Entry-point-specific info.

    caller_address: felt,
    // The execution is done in the context of the contract at this address.
    // It controls the storage being used, messages sent to L1, calling contracts, etc.
    contract_address: felt,
    // The entry point selector.
    selector: felt,
}

struct BlockInfo {
    block_number: felt,
    block_timestamp: felt,
    // The address of the sequencer that is creating this block.
    sequencer_address: felt,
}

struct TxInfo {
    // The version of the transaction. It is fixed in the OS, and should be signed by the account
    // contract.
    // This field allows invalidating old transactions, whenever the meaning of the other
    // transaction fields is changed (in the OS).
    version: felt,
    // The account contract from which this transaction originates.
    account_contract_address: felt,
    // The max_fee field of the transaction.
    max_fee: felt,
    // The signature of the transaction.
    signature_start: felt*,
    signature_end: felt*,
    // The hash of the transaction.
    transaction_hash: felt,
    // The identifier of the chain.
    // This field can be used to prevent replay of testnet transactions on mainnet.
    chain_id: felt,
    // The transaction's nonce.
    nonce: felt,
}

// Shared attributes.

struct RequestHeader {
    // The syscall selector.
    selector: felt,
    // The amount of gas left before the syscall execution.
    gas: felt,
}

struct ResponseHeader {
    // The amount of gas left after the syscall execution.
    gas: felt,
    // 0 if the syscall succeeded; 1 otherwise.
    failure_flag: felt,
}

struct FailureReason {
    start: felt*,
    end: felt*,
}

// Syscall requests.

struct CallContractRequest {
    // The address of the L2 contract to call.
    contract_address: felt,
    // The selector of the function to call.
    selector: felt,
    // The calldata.
    calldata_start: felt*,
    calldata_end: felt*,
}

struct LibraryCallRequest {
    // The hash of the class to run.
    class_hash: felt,
    // The selector of the function to call.
    selector: felt,
    // The calldata.
    calldata_start: felt*,
    calldata_end: felt*,
}

struct EmptyRequest {
}

struct DeployRequest {
    // The hash of the class to deploy.
    class_hash: felt,
    // A salt for the new contract address calculation.
    contract_address_salt: felt,
    // The calldata for the constructor.
    constructor_calldata_start: felt*,
    constructor_calldata_end: felt*,
    // Used for deterministic contract address deployment.
    deploy_from_zero: felt,
}

struct StorageReadRequest {
    reserved: felt,
    key: felt,
}

struct StorageWriteRequest {
    reserved: felt,
    key: felt,
    value: felt,
}

struct EmitEventRequest {
    keys_start: felt*,
    keys_end: felt*,
    data_start: felt*,
    data_end: felt*,
}

struct ReplaceClassRequest {
    class_hash: felt,
}

struct SendMessageToL1Request {
    to_address: felt,
    payload_start: felt*,
    payload_end: felt*,
}

// Syscall responses.

struct CallContractResponse {
    retdata_start: felt*,
    retdata_end: felt*,
}

struct DeployResponse {
    contract_address: felt,
    constructor_retdata_start: felt*,
    constructor_retdata_end: felt*,
}

struct StorageReadResponse {
    value: felt,
}

struct GetExecutionInfoResponse {
    execution_info: ExecutionInfo*,
}