"""Модели документов, fingerprints и логов использования."""

from datetime import datetime
from typing import TYPE_CHECKING

from sqlalchemy import JSON, BigInteger, ForeignKey, String, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base

if TYPE_CHECKING:
    from app.models.user import User


class Document(Base):
    """Документ в базе знаний системы (статья, книга, веб-страница)."""

    __tablename__ = "documents"

    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    # Источник: openalex, cyberleninka, arxiv, wikipedia_ru, wikipedia_en
    source: Mapped[str] = mapped_column(String(50), nullable=False, index=True)
    # Внешний ID (OpenAlex ID, arXiv ID и т.д.) — уникален в рамках источника
    ext_id: Mapped[str] = mapped_column(String(255), unique=True, index=True, nullable=False)
    doi: Mapped[str | None] = mapped_column(String(255), nullable=True, index=True)
    title: Mapped[str] = mapped_column(nullable=False)
    authors: Mapped[list] = mapped_column(JSON, default=list)
    year: Mapped[int | None] = mapped_column(nullable=True, index=True)
    lang: Mapped[str | None] = mapped_column(String(10), nullable=True, index=True)
    journal: Mapped[str | None] = mapped_column(nullable=True)
    volume: Mapped[str | None] = mapped_column(String(50), nullable=True)
    issue: Mapped[str | None] = mapped_column(String(50), nullable=True)
    pages: Mapped[str | None] = mapped_column(String(50), nullable=True)
    abstract: Mapped[str | None] = mapped_column(nullable=True)
    url: Mapped[str | None] = mapped_column(nullable=True)
    # Ключ объекта в MinIO (полный текст)
    minio_key: Mapped[str | None] = mapped_column(nullable=True)
    # ID вектора в FAISS индексе
    faiss_id: Mapped[int | None] = mapped_column(nullable=True, index=True)
    indexed_at: Mapped[datetime] = mapped_column(server_default=func.now())

    # Отпечатки (Winnowing хэши)
    fingerprints: Mapped[list["Fingerprint"]] = relationship(
        back_populates="document",
        lazy="select",
    )

    def __repr__(self) -> str:
        return f"<Document id={self.id} source={self.source!r} title={self.title[:40]!r}>"


class Fingerprint(Base):
    """Winnowing fingerprint (хэш n-граммы) для быстрого поиска плагиата."""

    __tablename__ = "fingerprints"

    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    doc_id: Mapped[int] = mapped_column(ForeignKey("documents.id"), index=True)
    hash_value: Mapped[int] = mapped_column(BigInteger, index=True)
    position: Mapped[int] = mapped_column()  # Позиция в документе

    document: Mapped["Document"] = relationship(back_populates="fingerprints")

    def __repr__(self) -> str:
        return f"<Fingerprint doc_id={self.doc_id} hash={self.hash_value}>"


class UsageLog(Base):
    """Лог использования для подсчёта лимитов по тарифу."""

    __tablename__ = "usage_logs"

    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    # Действие: search, plagiarism, summarize, gost
    action: Mapped[str] = mapped_column(String(50), nullable=False)
    created_at: Mapped[datetime] = mapped_column(server_default=func.now(), index=True)

    user: Mapped["User"] = relationship(back_populates="usage")

    def __repr__(self) -> str:
        return f"<UsageLog user_id={self.user_id} action={self.action!r}>"