import datetime

from sqlalchemy import Date, ForeignKey, Index, Integer, Text
from sqlalchemy import inspect
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from fabledassistant.models import Base
from fabledassistant.models.base import CreatedAtMixin, TimestampMixin


class Conversation(Base, TimestampMixin):
    __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="")
    # 'chat' (default) or 'briefing'. Briefing conversations are hidden from
    # the main chat view and managed by the briefing pipeline.
    conversation_type: Mapped[str] = mapped_column(Text, default="chat", server_default="chat")
    # For briefing conversations only: the calendar date this briefing covers.
    briefing_date: Mapped[datetime.date | None] = mapped_column(Date, nullable=True)

    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,
            "conversation_type": self.conversation_type,
            "briefing_date": self.briefing_date.isoformat() if self.briefing_date else None,
            "message_count": msg_count,
            "created_at": self.created_at.isoformat(),
            "updated_at": self.updated_at.isoformat(),
        }


class Message(Base, CreatedAtMixin):
    __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
    )
    tool_calls: Mapped[list | None] = mapped_column(JSONB, nullable=True)

    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,
            "tool_calls": self.tool_calls,
            "created_at": self.created_at.isoformat(),
        }