"""Tietokantamallit — SQLAlchemy 2.0, Mapped-tyypitys, ForeignKey-relaatiot."""

from datetime import datetime

from sqlalchemy import String, Text, DateTime, ForeignKey, create_engine
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship, sessionmaker

DATABASE_URL = "sqlite:///./app.db"
engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


class Base(DeclarativeBase):
    pass


class Author(Base):
    """Kirjoittaja — nimi, sähköposti ja bio."""

    __tablename__ = "authors"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    name: Mapped[str] = mapped_column(String(255))
    email: Mapped[str] = mapped_column(String(255), unique=True)
    bio: Mapped[str | None] = mapped_column(Text, default=None)

    posts: Mapped[list["Post"]] = relationship(back_populates="author")


class Post(Base):
    """Blogipostaus — otsikko, sisältö, kirjoittaja, julkaisuaika ja tila."""

    __tablename__ = "posts"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    title: Mapped[str] = mapped_column(String(255))
    content: Mapped[str] = mapped_column(Text)
    author_id: Mapped[int] = mapped_column(ForeignKey("authors.id"))
    published_at: Mapped[datetime | None] = mapped_column(DateTime, default=None)
    status: Mapped[str] = mapped_column(String(20), default="draft")

    author: Mapped["Author"] = relationship(back_populates="posts")


Base.metadata.create_all(bind=engine)