"""SQLAlchemy ORM models (SPEC.md §2). Separate from Pydantic schemas (spec §1)."""

from datetime import date, datetime

from sqlalchemy import CheckConstraint, ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship

from database import Base


class Food(Base):
    __tablename__ = "foods"
    __table_args__ = (
        # Meal nutrition is derived from components, never stored (spec §2.1)
        CheckConstraint("is_meal = 1 OR calories_per_unit IS NOT NULL"),
    )

    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str]
    brand: Mapped[str | None]
    barcode: Mapped[str | None] = mapped_column(unique=True)
    source: Mapped[str]  # "openfoodfacts" | "manual" | "meal"
    is_meal: Mapped[bool] = mapped_column(default=False)
    unit_type: Mapped[str] = mapped_column(default="weight")  # "weight" | "count"
    calories_per_unit: Mapped[float | None]
    protein_per_unit: Mapped[float | None]
    carbs_per_unit: Mapped[float | None]
    fat_per_unit: Mapped[float | None]
    fiber_per_unit: Mapped[float | None]
    saturated_fat_per_unit: Mapped[float | None]
    sugars_per_unit: Mapped[float | None]
    sodium_per_unit: Mapped[float | None]
    serving_size_g: Mapped[float | None]
    serving_name: Mapped[str | None]
    off_data: Mapped[str | None]  # raw OFF JSON blob as TEXT
    deleted_at: Mapped[datetime | None]
    created_at: Mapped[datetime]
    updated_at: Mapped[datetime]

    components: Mapped[list["MealComponent"]] = relationship(
        foreign_keys="MealComponent.meal_id", back_populates="meal"
    )


class MealComponent(Base):
    __tablename__ = "meal_components"

    id: Mapped[int] = mapped_column(primary_key=True)
    meal_id: Mapped[int] = mapped_column(ForeignKey("foods.id"))
    food_id: Mapped[int] = mapped_column(ForeignKey("foods.id"))
    quantity: Mapped[float]

    meal: Mapped[Food] = relationship(foreign_keys=[meal_id], back_populates="components")
    food: Mapped[Food] = relationship(foreign_keys=[food_id])


class DailyLogEntry(Base):
    __tablename__ = "daily_log"

    id: Mapped[int] = mapped_column(primary_key=True)
    date: Mapped[date]
    food_id: Mapped[int] = mapped_column(ForeignKey("foods.id"))
    quantity: Mapped[float]
    meal_slot: Mapped[str | None]  # "breakfast" | "lunch" | "dinner" | "snack"
    sort_order: Mapped[int] = mapped_column(default=0)
    created_at: Mapped[datetime]

    food: Mapped[Food] = relationship()


class Target(Base):
    __tablename__ = "targets"

    id: Mapped[int] = mapped_column(primary_key=True)
    start_date: Mapped[date]
    end_date: Mapped[date | None]  # null = currently active
    calories: Mapped[int]
    protein_g: Mapped[float | None]
    carbs_g: Mapped[float | None]
    fat_g: Mapped[float | None]