from datetime import datetime

from sqlalchemy import Column, DateTime, ForeignKey, String, Table, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db import Base


document_tag_relations = Table(
    "document_tag_relations",
    Base.metadata,
    Column("document_id", ForeignKey("documents.id"), primary_key=True),
    Column("tag_id", ForeignKey("document_tags.id"), primary_key=True),
)


class DocumentCategory(Base):
    __tablename__ = "document_categories"

    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str] = mapped_column(String(120), unique=True)
    parent_id: Mapped[int | None] = mapped_column(ForeignKey("document_categories.id"))


class DocumentTag(Base):
    __tablename__ = "document_tags"

    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str] = mapped_column(String(80), unique=True, index=True)

    documents: Mapped[list["Document"]] = relationship(secondary=document_tag_relations, back_populates="tags")


class Document(Base):
    __tablename__ = "documents"

    id: Mapped[int] = mapped_column(primary_key=True)
    title: Mapped[str] = mapped_column(String(255), index=True)
    version: Mapped[str | None] = mapped_column(String(60))
    adp_doc_id: Mapped[str | None] = mapped_column(String(120), unique=True)
    storage_key: Mapped[str | None] = mapped_column(String(255))
    secrecy_level: Mapped[str] = mapped_column(String(30), default="internal", index=True)
    status: Mapped[str] = mapped_column(String(30), default="pending", index=True)
    owner_dept: Mapped[str | None] = mapped_column(String(120))
    description: Mapped[str | None] = mapped_column(Text)
    created_by_id: Mapped[int | None] = mapped_column(ForeignKey("users.id"))
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

    tags: Mapped[list[DocumentTag]] = relationship(secondary=document_tag_relations, back_populates="documents")