import uuid
from datetime import datetime

from sqlalchemy import Boolean, CheckConstraint, DateTime, ForeignKey, Integer, JSON, String, Text, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.core.actors import ActorType
from app.models.base import Base, GUID


class Message(Base):
    __tablename__ = "messages"
    __table_args__ = (
        CheckConstraint(
            "(actor_type = 'AUTH_USER' AND actor_guest_id IS NULL) "
            "OR (actor_type = 'GUEST' AND actor_user_id IS NULL AND actor_guest_id IS NOT NULL)",
            name="ck_messages_actor_consistency",
        ),
    )

    id: Mapped[uuid.UUID] = mapped_column(GUID, primary_key=True, default=uuid.uuid4)
    discussion_id: Mapped[uuid.UUID] = mapped_column(
        GUID,
        ForeignKey("discussions.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    actor_type: Mapped[str] = mapped_column(
        String(20),
        nullable=False,
        default=ActorType.AUTH_USER.value,
        index=True,
    )
    actor_user_id: Mapped[uuid.UUID | None] = mapped_column(
        GUID,
        ForeignKey("utilisateurs.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    actor_guest_id: Mapped[uuid.UUID | None] = mapped_column(
        GUID,
        ForeignKey("guest_sessions.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    auteur_id: Mapped[uuid.UUID | None] = mapped_column(
        GUID,
        ForeignKey("utilisateurs.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    auteur_nom: Mapped[str] = mapped_column(String(200), nullable=False)
    contenu: Mapped[str] = mapped_column(Text, nullable=False)
    type: Mapped[str] = mapped_column(String(20), default="USER", nullable=False)
    # Possible values: USER, SUPPORT, PRIVATE

    est_lu: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
    numero_sequence: Mapped[int | None] = mapped_column(Integer, nullable=True)
    pieces_jointes: Mapped[list[str]] = mapped_column(
        JSON, default=list, nullable=False, server_default="[]"
    )
    date_creation: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False, index=True
    )

    # Relationships
    discussion: Mapped["Discussion"] = relationship("Discussion", back_populates="messages")
    auteur: Mapped["Utilisateur | None"] = relationship("Utilisateur", foreign_keys=[auteur_id])
    actor_user: Mapped["Utilisateur | None"] = relationship("Utilisateur", foreign_keys=[actor_user_id])
    actor_guest: Mapped["GuestSession | None"] = relationship("GuestSession")


from app.models.discussion import Discussion  # noqa: E402, F401
from app.models.utilisateur import Utilisateur  # noqa: E402, F401
from app.models.guest_session import GuestSession  # noqa: E402, F401