from dataclasses import dataclass, field
from typing import List, Optional


# --- MARC XML structures ---
@dataclass
class ControlField:
    tag: str
    value: str


@dataclass
class SubField:
    code: str
    value: str


@dataclass
class DataField:
    tag: str
    ind1: str = " "
    ind2: str = " "
    subfields: List[SubField] = field(default_factory=list)


@dataclass
class MarcRecord:
    leader: str
    controlfields: List[ControlField] = field(default_factory=list)
    datafields: List[DataField] = field(default_factory=list)


# --- SRU record wrapper ---
@dataclass
class Record:
    recordSchema: str
    recordPacking: str
    recordData: MarcRecord
    recordPosition: int


@dataclass
class EchoedSearchRequest:
    version: str
    query: str
    maximumRecords: int
    recordPacking: str
    recordSchema: str


@dataclass
class SearchRetrieveResponse:
    version: str
    numberOfRecords: int
    records: List[Record] = field(default_factory=list)
    echoedSearchRetrieveRequest: Optional[EchoedSearchRequest] = None