import uuid
from typing import Any

from sqlalchemy import Enum, ForeignKey, Text
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
from app.models.enums import ConversationMode, ConversationStatus, MessageRole


class Conversation(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    """Chat thread. The only core mode is query (RAG Q&A); EE adds insight.

    Capture is no longer a conversation — it writes a Document directly (see
    app/authoring/) — so this table holds no per-turn engine state any more.
    """

    __tablename__ = "conversations"

    mode: Mapped[ConversationMode] = mapped_column(
        Enum(ConversationMode, native_enum=False, length=32)
    )
    status: Mapped[ConversationStatus] = mapped_column(
        Enum(ConversationStatus, native_enum=False, length=32),
        default=ConversationStatus.active,
    )
    user_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("users.id", ondelete="CASCADE"), index=True
    )

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


class Message(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    __tablename__ = "messages"

    conversation_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("conversations.id", ondelete="CASCADE"), index=True
    )
    role: Mapped[MessageRole] = mapped_column(
        Enum(MessageRole, native_enum=False, length=32)
    )
    content: Mapped[str] = mapped_column(Text)
    # Assistant turns snapshot their citations here ({"sources": [...]}) so
    # they survive reload and re-indexing — chunks are disposable, the
    # rendered citation is not.
    meta: Mapped[dict[str, Any]] = mapped_column(
        JSONB, default=dict, server_default="{}"
    )

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