from datetime import datetime, timezone

from sqlalchemy import DateTime, ForeignKey, Integer, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


def _utcnow() -> datetime:
    return datetime.now(timezone.utc)


class Recipe(Base):
    __tablename__ = "recipes"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    slug: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
    category: Mapped[str | None] = mapped_column(String(100), nullable=True)
    image_filename: Mapped[str | None] = mapped_column(String(255), nullable=True)

    preptime: Mapped[str | None] = mapped_column(String(100), nullable=True)
    cooktime: Mapped[str | None] = mapped_column(String(100), nullable=True)
    baketime: Mapped[str | None] = mapped_column(String(100), nullable=True)
    cooltime: Mapped[str | None] = mapped_column(String(100), nullable=True)
    marinade_time: Mapped[str | None] = mapped_column(String(100), nullable=True)
    robot_time: Mapped[str | None] = mapped_column(String(100), nullable=True)
    servings: Mapped[str | None] = mapped_column(String(50), nullable=True)

    notes: Mapped[str | None] = mapped_column(Text, nullable=True)

    kcal: Mapped[str | None] = mapped_column(String(50), nullable=True)
    kh: Mapped[str | None] = mapped_column(String(50), nullable=True)
    protein: Mapped[str | None] = mapped_column(String(50), nullable=True)
    fett: Mapped[str | None] = mapped_column(String(50), nullable=True)

    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=_utcnow, onupdate=_utcnow
    )

    ingredients: Mapped[list["Ingredient"]] = relationship(
        back_populates="recipe", cascade="all, delete-orphan", order_by="Ingredient.position"
    )
    steps: Mapped[list["Step"]] = relationship(
        back_populates="recipe", cascade="all, delete-orphan", order_by="Step.position"
    )
    book_links: Mapped[list["BookRecipe"]] = relationship(
        back_populates="recipe", cascade="all, delete-orphan"
    )


class Ingredient(Base):
    __tablename__ = "ingredients"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    recipe_id: Mapped[int] = mapped_column(ForeignKey("recipes.id"), nullable=False)
    position: Mapped[int] = mapped_column(Integer, nullable=False)
    kind: Mapped[str] = mapped_column(String(20), nullable=False, default="item")  # item | section_header
    quantity: Mapped[str | None] = mapped_column(String(50), nullable=True)
    unit: Mapped[str | None] = mapped_column(String(50), nullable=True)
    text: Mapped[str] = mapped_column(String(255), nullable=False)

    recipe: Mapped["Recipe"] = relationship(back_populates="ingredients")


class Step(Base):
    __tablename__ = "steps"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    recipe_id: Mapped[int] = mapped_column(ForeignKey("recipes.id"), nullable=False)
    position: Mapped[int] = mapped_column(Integer, nullable=False)
    text: Mapped[str] = mapped_column(Text, nullable=False)

    recipe: Mapped["Recipe"] = relationship(back_populates="steps")


class Book(Base):
    __tablename__ = "books"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    name: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)

    recipe_links: Mapped[list["BookRecipe"]] = relationship(
        back_populates="book", cascade="all, delete-orphan"
    )


class BookRecipe(Base):
    __tablename__ = "book_recipes"
    __table_args__ = (UniqueConstraint("book_id", "recipe_id", name="uq_book_recipe"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    book_id: Mapped[int] = mapped_column(ForeignKey("books.id"), nullable=False)
    recipe_id: Mapped[int] = mapped_column(ForeignKey("recipes.id"), nullable=False)
    chapter: Mapped[str | None] = mapped_column(String(100), nullable=True)
    position: Mapped[int] = mapped_column(Integer, nullable=False, default=0)

    book: Mapped["Book"] = relationship(back_populates="recipe_links")
    recipe: Mapped["Recipe"] = relationship(back_populates="book_links")