import uuid
from sqlalchemy import Column, String, Boolean, Date, ForeignKey, UniqueConstraint
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import relationship
from backend.database import Base

class User(Base):
    __tablename__ = "users"
    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    name = Column(String, nullable=False)

    items = relationship("Item", back_populates="user", cascade="all, delete")
    tags = relationship("Tag", back_populates="user", cascade="all, delete")
    trips = relationship("Trip", back_populates="user", cascade="all, delete")

class Item(Base):
    __tablename__ = "items"
    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=False)
    name = Column(String, nullable=False)  # z.B. "Zahnbürste" oder "{days} x Vitamin D3"

    user = relationship("User", back_populates="items")
    tags = relationship("ItemTag", back_populates="item", cascade="all, delete")
    trip_items = relationship("TripItem", back_populates="item", cascade="all, delete")

class Tag(Base):
    __tablename__ = "tags"
    __table_args__ = (UniqueConstraint("user_id", "name", name="uq_tag_user_name"),)

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=False)
    name = Column(String, nullable=False)

    user = relationship("User", back_populates="tags")
    items = relationship("ItemTag", back_populates="tag", cascade="all, delete")
    trip_selected_tags = relationship("TripTagSelected", back_populates="tag", cascade="all, delete")
    trip_marked_tags = relationship("TripTagMarked", back_populates="tag", cascade="all, delete")
    trip_items = relationship("TripItem", back_populates="tag")

class ItemTag(Base):
    __tablename__ = "item_tags"
    item_id = Column(UUID(as_uuid=True), ForeignKey("items.id", ondelete="CASCADE"), primary_key=True)
    tag_id = Column(UUID(as_uuid=True), ForeignKey("tags.id", ondelete="CASCADE"), primary_key=True)

    item = relationship("Item", back_populates="tags")
    tag = relationship("Tag", back_populates="items")

class Trip(Base):
    __tablename__ = "trips"
    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=False)
    name = Column(String)
    start_date = Column(Date)
    end_date = Column(Date)

    user = relationship("User", back_populates="trips")
    selected_tags = relationship("TripTagSelected", back_populates="trip", cascade="all, delete")
    marked_tags = relationship("TripTagMarked", back_populates="trip", cascade="all, delete")
    trip_items = relationship("TripItem", back_populates="trip", cascade="all, delete")

class TripTagSelected(Base):
    __tablename__ = "trip_tag_selected"
    trip_id = Column(UUID(as_uuid=True), ForeignKey("trips.id", ondelete="CASCADE"), primary_key=True)
    tag_id = Column(UUID(as_uuid=True), ForeignKey("tags.id"), primary_key=True)

    trip = relationship("Trip", back_populates="selected_tags")
    tag = relationship("Tag", back_populates="trip_selected_tags")

class TripTagMarked(Base):
    __tablename__ = "trip_tag_marked"
    trip_id = Column(UUID(as_uuid=True), ForeignKey("trips.id", ondelete="CASCADE"), primary_key=True)
    tag_id = Column(UUID(as_uuid=True), ForeignKey("tags.id"), primary_key=True)

    trip = relationship("Trip", back_populates="marked_tags")
    tag = relationship("Tag", back_populates="trip_marked_tags")

class TripItem(Base):
    __tablename__ = "trip_items"
    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    trip_id = Column(UUID(as_uuid=True), ForeignKey("trips.id", ondelete="CASCADE"), nullable=False)
    item_id = Column(UUID(as_uuid=True), ForeignKey("items.id"), nullable=False)
    name_calculated = Column(String, nullable=False)
    checked = Column(Boolean, nullable=False, default=False)
    tag_id = Column(UUID(as_uuid=True), ForeignKey("tags.id"), nullable=True)  # null = gemeinsames Item

    trip = relationship("Trip", back_populates="trip_items")
    item = relationship("Item", back_populates="trip_items")
    tag = relationship("Tag", back_populates="trip_items")