from datetime import datetime, timezone

from sqlalchemy import DateTime, ForeignKey, Index, Integer, Text
from sqlalchemy import inspect
from sqlalchemy.orm import Mapped, mapped_column, relationship

from fabledassistant.models import Base


class Conversation(Base):
    __tablename__ = "conversations"

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int | None] = mapped_column(
        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=True
    )
    title: Mapped[str] = mapped_column(Text, default="")
    model: Mapped[str] = mapped_column(Text, default="")
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    messages: Mapped[list["Message"]] = relationship(
        back_populates="conversation",
        cascade="all, delete-orphan",
        order_by="Message.created_at",
    )

    __table_args__ = (
        Index("ix_conversations_updated_at", "updated_at"),
        Index("ix_conversations_user_id", "user_id"),
    )

    def to_dict(self) -> dict:
        # Use loaded messages if available, otherwise 0
        if "messages" in inspect(self).dict:
            msg_count = len(self.messages) if self.messages else 0
        else:
            msg_count = 0
        return {
            "id": self.id,
            "title": self.title,
            "model": self.model,
            "message_count": msg_count,
            "created_at": self.created_at.isoformat(),
            "updated_at": self.updated_at.isoformat(),
        }


class Message(Base):
    __tablename__ = "messages"

    id: Mapped[int] = mapped_column(primary_key=True)
    conversation_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("conversations.id", ondelete="CASCADE")
    )
    role: Mapped[str] = mapped_column(Text)
    content: Mapped[str] = mapped_column(Text, default="")
    status: Mapped[str] = mapped_column(Text, default="complete")
    context_note_id: Mapped[int | None] = mapped_column(
        Integer, ForeignKey("notes.id", ondelete="SET NULL"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )

    conversation: Mapped["Conversation"] = relationship(back_populates="messages")

    __table_args__ = (
        Index("ix_messages_conversation_id", "conversation_id"),
    )

    def to_dict(self) -> dict:
        return {
            "id": self.id,
            "conversation_id": self.conversation_id,
            "role": self.role,
            "content": self.content,
            "status": self.status,
            "context_note_id": self.context_note_id,
            "created_at": self.created_at.isoformat(),
        }