danswer/backend/danswer/db/chat.py

from collections.abc import Sequence
from datetime import datetime
from datetime import timedelta
from uuid import UUID

from sqlalchemy import delete
from sqlalchemy import desc
from sqlalchemy import func
from sqlalchemy import nullsfirst
from sqlalchemy import or_
from sqlalchemy import select
from sqlalchemy import update
from sqlalchemy.exc import MultipleResultsFound
from sqlalchemy.orm import joinedload
from sqlalchemy.orm import Session

from danswer.auth.schemas import UserRole
from danswer.chat.models import DocumentRelevance
from danswer.configs.chat_configs import HARD_DELETE_CHATS
from danswer.configs.constants import MessageType
from danswer.db.models import ChatMessage
from danswer.db.models import ChatMessage__SearchDoc
from danswer.db.models import ChatSession
from danswer.db.models import ChatSessionSharedStatus
from danswer.db.models import Prompt
from danswer.db.models import SearchDoc
from danswer.db.models import SearchDoc as DBSearchDoc
from danswer.db.models import ToolCall
from danswer.db.models import User
from danswer.db.pg_file_store import delete_lobj_by_name
from danswer.file_store.models import FileDescriptor
from danswer.llm.override_models import LLMOverride
from danswer.llm.override_models import PromptOverride
from danswer.search.models import RetrievalDocs
from danswer.search.models import SavedSearchDoc
from danswer.search.models import SearchDoc as ServerSearchDoc
from danswer.server.query_and_chat.models import ChatMessageDetail
from danswer.tools.tool_runner import ToolCallFinalResult
from danswer.utils.logger import setup_logger


logger = setup_logger()


def get_chat_session_by_id(
    chat_session_id: UUID,
    user_id: UUID | None,
    db_session: Session,
    include_deleted: bool = False,
    is_shared: bool = False,
) -> ChatSession:
    stmt = select(ChatSession).where(ChatSession.id == chat_session_id)

    if is_shared:
        stmt = stmt.where(ChatSession.shared_status == ChatSessionSharedStatus.PUBLIC)
    else:
        # if user_id is None, assume this is an admin who should be able
        # to view all chat sessions
        if user_id is not None:
            stmt = stmt.where(
                or_(ChatSession.user_id == user_id, ChatSession.user_id.is_(None))
            )

    result = db_session.execute(stmt)
    chat_session = result.scalar_one_or_none()

    if not chat_session:
        raise ValueError("Invalid Chat Session ID provided")

    if not include_deleted and chat_session.deleted:
        raise ValueError("Chat session has been deleted")

    return chat_session


def get_chat_sessions_by_slack_thread_id(
    slack_thread_id: str,
    user_id: UUID | None,
    db_session: Session,
) -> Sequence[ChatSession]:
    stmt = select(ChatSession).where(ChatSession.slack_thread_id == slack_thread_id)
    if user_id is not None:
        stmt = stmt.where(
            or_(ChatSession.user_id == user_id, ChatSession.user_id.is_(None))
        )
    return db_session.scalars(stmt).all()


def get_valid_messages_from_query_sessions(
    chat_session_ids: list[UUID],
    db_session: Session,
) -> dict[UUID, str]:
    user_message_subquery = (
        select(
            ChatMessage.chat_session_id, func.min(ChatMessage.id).label("user_msg_id")
        )
        .where(
            ChatMessage.chat_session_id.in_(chat_session_ids),
            ChatMessage.message_type == MessageType.USER,
        )
        .group_by(ChatMessage.chat_session_id)
        .subquery()
    )

    assistant_message_subquery = (
        select(
            ChatMessage.chat_session_id,
            func.min(ChatMessage.id).label("assistant_msg_id"),
        )
        .where(
            ChatMessage.chat_session_id.in_(chat_session_ids),
            ChatMessage.message_type == MessageType.ASSISTANT,
        )
        .group_by(ChatMessage.chat_session_id)
        .subquery()
    )

    query = (
        select(ChatMessage.chat_session_id, ChatMessage.message)
        .join(
            user_message_subquery,
            ChatMessage.chat_session_id == user_message_subquery.c.chat_session_id,
        )
        .join(
            assistant_message_subquery,
            ChatMessage.chat_session_id == assistant_message_subquery.c.chat_session_id,
        )
        .join(
            ChatMessage__SearchDoc,
            ChatMessage__SearchDoc.chat_message_id
            == assistant_message_subquery.c.assistant_msg_id,
        )
        .where(ChatMessage.id == user_message_subquery.c.user_msg_id)
    )

    first_messages = db_session.execute(query).all()
    logger.info(f"Retrieved {len(first_messages)} first messages with documents")

    return {row.chat_session_id: row.message for row in first_messages}


def get_chat_sessions_by_user(
    user_id: UUID | None,
    deleted: bool | None,
    db_session: Session,
    only_one_shot: bool = False,
    limit: int = 50,
) -> list[ChatSession]:
    stmt = select(ChatSession).where(ChatSession.user_id == user_id)

    if only_one_shot:
        stmt = stmt.where(ChatSession.one_shot.is_(True))
    else:
        stmt = stmt.where(ChatSession.one_shot.is_(False))

    stmt = stmt.order_by(desc(ChatSession.time_created))

    if deleted is not None:
        stmt = stmt.where(ChatSession.deleted == deleted)

    if limit:
        stmt = stmt.limit(limit)

    result = db_session.execute(stmt)
    chat_sessions = result.scalars().all()

    return list(chat_sessions)


def delete_search_doc_message_relationship(
    message_id: int, db_session: Session
) -> None:
    db_session.query(ChatMessage__SearchDoc).filter(
        ChatMessage__SearchDoc.chat_message_id == message_id
    ).delete(synchronize_session=False)

    db_session.commit()


def delete_tool_call_for_message_id(message_id: int, db_session: Session) -> None:
    stmt = delete(ToolCall).where(ToolCall.message_id == message_id)
    db_session.execute(stmt)
    db_session.commit()


def delete_orphaned_search_docs(db_session: Session) -> None:
    orphaned_docs = (
        db_session.query(SearchDoc)
        .outerjoin(ChatMessage__SearchDoc)
        .filter(ChatMessage__SearchDoc.chat_message_id.is_(None))
        .all()
    )
    for doc in orphaned_docs:
        db_session.delete(doc)
    db_session.commit()


def delete_messages_and_files_from_chat_session(
    chat_session_id: UUID, db_session: Session
) -> None:
    # Select messages older than cutoff_time with files
    messages_with_files = db_session.execute(
        select(ChatMessage.id, ChatMessage.files).where(
            ChatMessage.chat_session_id == chat_session_id,
        )
    ).fetchall()

    for id, files in messages_with_files:
        delete_tool_call_for_message_id(message_id=id, db_session=db_session)
        delete_search_doc_message_relationship(message_id=id, db_session=db_session)
        for file_info in files or {}:
            lobj_name = file_info.get("id")
            if lobj_name:
                logger.info(f"Deleting file with name: {lobj_name}")
                delete_lobj_by_name(lobj_name, db_session)

    db_session.execute(
        delete(ChatMessage).where(ChatMessage.chat_session_id == chat_session_id)
    )
    db_session.commit()

    delete_orphaned_search_docs(db_session)


def create_chat_session(
    db_session: Session,
    description: str,
    user_id: UUID | None,
    persona_id: int | None,  # Can be none if temporary persona is used
    llm_override: LLMOverride | None = None,
    prompt_override: PromptOverride | None = None,
    one_shot: bool = False,
    danswerbot_flow: bool = False,
    slack_thread_id: str | None = None,
) -> ChatSession:
    chat_session = ChatSession(
        user_id=user_id,
        persona_id=persona_id,
        description=description,
        llm_override=llm_override,
        prompt_override=prompt_override,
        one_shot=one_shot,
        danswerbot_flow=danswerbot_flow,
        slack_thread_id=slack_thread_id,
    )

    db_session.add(chat_session)
    db_session.commit()

    return chat_session


def update_chat_session(
    db_session: Session,
    user_id: UUID | None,
    chat_session_id: UUID,
    description: str | None = None,
    sharing_status: ChatSessionSharedStatus | None = None,
) -> ChatSession:
    chat_session = get_chat_session_by_id(
        chat_session_id=chat_session_id, user_id=user_id, db_session=db_session
    )

    if chat_session.deleted:
        raise ValueError("Trying to rename a deleted chat session")

    if description is not None:
        chat_session.description = description
    if sharing_status is not None:
        chat_session.shared_status = sharing_status

    db_session.commit()

    return chat_session


def delete_chat_session(
    user_id: UUID | None,
    chat_session_id: UUID,
    db_session: Session,
    hard_delete: bool = HARD_DELETE_CHATS,
) -> None:
    chat_session = get_chat_session_by_id(
        chat_session_id=chat_session_id, user_id=user_id, db_session=db_session
    )

    if chat_session.deleted:
        raise ValueError("Cannot delete an already deleted chat session")

    if hard_delete:
        delete_messages_and_files_from_chat_session(chat_session_id, db_session)
        db_session.execute(delete(ChatSession).where(ChatSession.id == chat_session_id))
    else:
        chat_session = get_chat_session_by_id(
            chat_session_id=chat_session_id, user_id=user_id, db_session=db_session
        )
        chat_session.deleted = True

    db_session.commit()


def delete_chat_sessions_older_than(days_old: int, db_session: Session) -> None:
    cutoff_time = datetime.utcnow() - timedelta(days=days_old)
    old_sessions = db_session.execute(
        select(ChatSession.user_id, ChatSession.id).where(
            ChatSession.time_created < cutoff_time
        )
    ).fetchall()

    for user_id, session_id in old_sessions:
        delete_chat_session(user_id, session_id, db_session, hard_delete=True)


def get_chat_message(
    chat_message_id: int,
    user_id: UUID | None,
    db_session: Session,
) -> ChatMessage:
    stmt = select(ChatMessage).where(ChatMessage.id == chat_message_id)

    result = db_session.execute(stmt)
    chat_message = result.scalar_one_or_none()

    if not chat_message:
        raise ValueError("Invalid Chat Message specified")

    chat_user = chat_message.chat_session.user
    expected_user_id = chat_user.id if chat_user is not None else None

    if expected_user_id != user_id:
        logger.error(
            f"User {user_id} tried to fetch a chat message that does not belong to them"
        )
        raise ValueError("Chat message does not belong to user")

    return chat_message


def get_chat_messages_by_sessions(
    chat_session_ids: list[UUID],
    user_id: UUID | None,
    db_session: Session,
    skip_permission_check: bool = False,
) -> Sequence[ChatMessage]:
    if not skip_permission_check:
        for chat_session_id in chat_session_ids:
            get_chat_session_by_id(
                chat_session_id=chat_session_id, user_id=user_id, db_session=db_session
            )
    stmt = (
        select(ChatMessage)
        .where(ChatMessage.chat_session_id.in_(chat_session_ids))
        .order_by(nullsfirst(ChatMessage.parent_message))
    )
    return db_session.execute(stmt).scalars().all()


def get_search_docs_for_chat_message(
    chat_message_id: int, db_session: Session
) -> list[SearchDoc]:
    stmt = (
        select(SearchDoc)
        .join(
            ChatMessage__SearchDoc, ChatMessage__SearchDoc.search_doc_id == SearchDoc.id
        )
        .where(ChatMessage__SearchDoc.chat_message_id == chat_message_id)
    )

    return list(db_session.scalars(stmt).all())


def get_chat_messages_by_session(
    chat_session_id: UUID,
    user_id: UUID | None,
    db_session: Session,
    skip_permission_check: bool = False,
    prefetch_tool_calls: bool = False,
) -> list[ChatMessage]:
    if not skip_permission_check:
        get_chat_session_by_id(
            chat_session_id=chat_session_id, user_id=user_id, db_session=db_session
        )

    stmt = (
        select(ChatMessage)
        .where(ChatMessage.chat_session_id == chat_session_id)
        .order_by(nullsfirst(ChatMessage.parent_message))
    )

    if prefetch_tool_calls:
        stmt = stmt.options(joinedload(ChatMessage.tool_call))
        result = db_session.scalars(stmt).unique().all()
    else:
        result = db_session.scalars(stmt).all()

    return list(result)


def get_or_create_root_message(
    chat_session_id: UUID,
    db_session: Session,
) -> ChatMessage:
    try:
        root_message: ChatMessage | None = (
            db_session.query(ChatMessage)
            .filter(
                ChatMessage.chat_session_id == chat_session_id,
                ChatMessage.parent_message.is_(None),
            )
            .one_or_none()
        )
    except MultipleResultsFound:
        raise Exception(
            "Multiple root messages found for chat session. Data inconsistency detected."
        )

    if root_message is not None:
        return root_message
    else:
        new_root_message = ChatMessage(
            chat_session_id=chat_session_id,
            prompt_id=None,
            parent_message=None,
            latest_child_message=None,
            message="",
            token_count=0,
            message_type=MessageType.SYSTEM,
        )
        db_session.add(new_root_message)
        db_session.commit()
        return new_root_message


def reserve_message_id(
    db_session: Session,
    chat_session_id: UUID,
    parent_message: int,
    message_type: MessageType,
) -> int:
    # Create an empty chat message
    empty_message = ChatMessage(
        chat_session_id=chat_session_id,
        parent_message=parent_message,
        latest_child_message=None,
        message="",
        token_count=0,
        message_type=message_type,
    )

    # Add the empty message to the session
    db_session.add(empty_message)

    # Flush the session to get an ID for the new chat message
    db_session.flush()

    # Get the ID of the newly created message
    new_id = empty_message.id

    return new_id


def create_new_chat_message(
    chat_session_id: UUID,
    parent_message: ChatMessage,
    message: str,
    prompt_id: int | None,
    token_count: int,
    message_type: MessageType,
    db_session: Session,
    files: list[FileDescriptor] | None = None,
    rephrased_query: str | None = None,
    error: str | None = None,
    reference_docs: list[DBSearchDoc] | None = None,
    alternate_assistant_id: int | None = None,
    # Maps the citation number [n] to the DB SearchDoc
    citations: dict[int, int] | None = None,
    tool_call: ToolCall | None = None,
    commit: bool = True,
    reserved_message_id: int | None = None,
    overridden_model: str | None = None,
) -> ChatMessage:
    if reserved_message_id is not None:
        # Edit existing message
        existing_message = db_session.query(ChatMessage).get(reserved_message_id)
        if existing_message is None:
            raise ValueError(f"No message found with id {reserved_message_id}")

        existing_message.chat_session_id = chat_session_id
        existing_message.parent_message = parent_message.id
        existing_message.message = message
        existing_message.rephrased_query = rephrased_query
        existing_message.prompt_id = prompt_id
        existing_message.token_count = token_count
        existing_message.message_type = message_type
        existing_message.citations = citations
        existing_message.files = files
        existing_message.tool_call = tool_call
        existing_message.error = error
        existing_message.alternate_assistant_id = alternate_assistant_id
        existing_message.overridden_model = overridden_model

        new_chat_message = existing_message
    else:
        # Create new message
        new_chat_message = ChatMessage(
            chat_session_id=chat_session_id,
            parent_message=parent_message.id,
            latest_child_message=None,
            message=message,
            rephrased_query=rephrased_query,
            prompt_id=prompt_id,
            token_count=token_count,
            message_type=message_type,
            citations=citations,
            files=files,
            tool_call=tool_call,
            error=error,
            alternate_assistant_id=alternate_assistant_id,
            overridden_model=overridden_model,
        )
        db_session.add(new_chat_message)

    # SQL Alchemy will propagate this to update the reference_docs' foreign keys
    if reference_docs:
        new_chat_message.search_docs = reference_docs

    # Flush the session to get an ID for the new chat message
    db_session.flush()

    parent_message.latest_child_message = new_chat_message.id
    if commit:
        db_session.commit()

    return new_chat_message


def set_as_latest_chat_message(
    chat_message: ChatMessage,
    user_id: UUID | None,
    db_session: Session,
) -> None:
    parent_message_id = chat_message.parent_message

    if parent_message_id is None:
        raise RuntimeError(
            f"Trying to set a latest message without parent, message id: {chat_message.id}"
        )

    parent_message = get_chat_message(
        chat_message_id=parent_message_id, user_id=user_id, db_session=db_session
    )

    parent_message.latest_child_message = chat_message.id

    db_session.commit()


def attach_files_to_chat_message(
    chat_message: ChatMessage,
    files: list[FileDescriptor],
    db_session: Session,
    commit: bool = True,
) -> None:
    chat_message.files = files
    if commit:
        db_session.commit()


def get_prompt_by_id(
    prompt_id: int,
    user: User | None,
    db_session: Session,
    include_deleted: bool = False,
) -> Prompt:
    stmt = select(Prompt).where(Prompt.id == prompt_id)

    # if user is not specified OR they are an admin, they should
    # have access to all prompts, so this where clause is not needed
    if user and user.role != UserRole.ADMIN:
        stmt = stmt.where(or_(Prompt.user_id == user.id, Prompt.user_id.is_(None)))

    if not include_deleted:
        stmt = stmt.where(Prompt.deleted.is_(False))

    result = db_session.execute(stmt)
    prompt = result.scalar_one_or_none()

    if prompt is None:
        raise ValueError(
            f"Prompt with ID {prompt_id} does not exist or does not belong to user"
        )

    return prompt


def get_doc_query_identifiers_from_model(
    search_doc_ids: list[int],
    chat_session: ChatSession,
    user_id: UUID | None,
    db_session: Session,
    enforce_chat_session_id_for_search_docs: bool,
) -> list[tuple[str, int]]:
    """Given a list of search_doc_ids"""
    search_docs = (
        db_session.query(SearchDoc).filter(SearchDoc.id.in_(search_doc_ids)).all()
    )

    if user_id != chat_session.user_id:
        logger.error(
            f"Docs referenced are from a chat session not belonging to user {user_id}"
        )
        raise ValueError("Docs references do not belong to user")

    try:
        if any(
            [
                doc.chat_messages[0].chat_session_id != chat_session.id
                for doc in search_docs
            ]
        ):
            if enforce_chat_session_id_for_search_docs:
                raise ValueError("Invalid reference doc, not from this chat session.")
    except IndexError:
        # This happens when the doc has no chat_messages associated with it.
        # which happens as an edge case where the chat message failed to save
        # This usually happens when the LLM fails either immediately or partially through.
        raise RuntimeError("Chat session failed, please start a new session.")

    doc_query_identifiers = [(doc.document_id, doc.chunk_ind) for doc in search_docs]

    return doc_query_identifiers


def update_search_docs_table_with_relevance(
    db_session: Session,
    reference_db_search_docs: list[SearchDoc],
    relevance_summary: DocumentRelevance,
) -> None:
    for search_doc in reference_db_search_docs:
        relevance_data = relevance_summary.relevance_summaries.get(
            search_doc.document_id
        )
        if relevance_data is not None:
            db_session.execute(
                update(SearchDoc)
                .where(SearchDoc.id == search_doc.id)
                .values(
                    is_relevant=relevance_data.relevant,
                    relevance_explanation=relevance_data.content,
                )
            )
    db_session.commit()


def create_db_search_doc(
    server_search_doc: ServerSearchDoc,
    db_session: Session,
) -> SearchDoc:
    db_search_doc = SearchDoc(
        document_id=server_search_doc.document_id,
        chunk_ind=server_search_doc.chunk_ind,
        semantic_id=server_search_doc.semantic_identifier,
        link=server_search_doc.link,
        blurb=server_search_doc.blurb,
        source_type=server_search_doc.source_type,
        boost=server_search_doc.boost,
        hidden=server_search_doc.hidden,
        doc_metadata=server_search_doc.metadata,
        is_relevant=server_search_doc.is_relevant,
        relevance_explanation=server_search_doc.relevance_explanation,
        # For docs further down that aren't reranked, we can't use the retrieval score
        score=server_search_doc.score or 0.0,
        match_highlights=server_search_doc.match_highlights,
        updated_at=server_search_doc.updated_at,
        primary_owners=server_search_doc.primary_owners,
        secondary_owners=server_search_doc.secondary_owners,
        is_internet=server_search_doc.is_internet,
    )

    db_session.add(db_search_doc)
    db_session.commit()
    return db_search_doc


def get_db_search_doc_by_id(doc_id: int, db_session: Session) -> DBSearchDoc | None:
    """There are no safety checks here like user permission etc., use with caution"""
    search_doc = db_session.query(SearchDoc).filter(SearchDoc.id == doc_id).first()
    return search_doc


def translate_db_search_doc_to_server_search_doc(
    db_search_doc: SearchDoc,
    remove_doc_content: bool = False,
) -> SavedSearchDoc:
    return SavedSearchDoc(
        db_doc_id=db_search_doc.id,
        document_id=db_search_doc.document_id,
        chunk_ind=db_search_doc.chunk_ind,
        semantic_identifier=db_search_doc.semantic_id,
        link=db_search_doc.link,
        blurb=db_search_doc.blurb if not remove_doc_content else "",
        source_type=db_search_doc.source_type,
        boost=db_search_doc.boost,
        hidden=db_search_doc.hidden,
        metadata=db_search_doc.doc_metadata if not remove_doc_content else {},
        score=db_search_doc.score,
        match_highlights=(
            db_search_doc.match_highlights if not remove_doc_content else []
        ),
        relevance_explanation=db_search_doc.relevance_explanation,
        is_relevant=db_search_doc.is_relevant,
        updated_at=db_search_doc.updated_at if not remove_doc_content else None,
        primary_owners=db_search_doc.primary_owners if not remove_doc_content else [],
        secondary_owners=(
            db_search_doc.secondary_owners if not remove_doc_content else []
        ),
        is_internet=db_search_doc.is_internet,
    )


def get_retrieval_docs_from_chat_message(
    chat_message: ChatMessage, remove_doc_content: bool = False
) -> RetrievalDocs:
    top_documents = [
        translate_db_search_doc_to_server_search_doc(
            db_doc, remove_doc_content=remove_doc_content
        )
        for db_doc in chat_message.search_docs
    ]
    top_documents = sorted(top_documents, key=lambda doc: doc.score, reverse=True)  # type: ignore
    return RetrievalDocs(top_documents=top_documents)


def translate_db_message_to_chat_message_detail(
    chat_message: ChatMessage,
    remove_doc_content: bool = False,
) -> ChatMessageDetail:
    chat_msg_detail = ChatMessageDetail(
        chat_session_id=chat_message.chat_session_id,
        message_id=chat_message.id,
        parent_message=chat_message.parent_message,
        latest_child_message=chat_message.latest_child_message,
        message=chat_message.message,
        rephrased_query=chat_message.rephrased_query,
        context_docs=get_retrieval_docs_from_chat_message(
            chat_message, remove_doc_content=remove_doc_content
        ),
        message_type=chat_message.message_type,
        time_sent=chat_message.time_sent,
        citations=chat_message.citations,
        files=chat_message.files or [],
        tool_call=ToolCallFinalResult(
            tool_name=chat_message.tool_call.tool_name,
            tool_args=chat_message.tool_call.tool_arguments,
            tool_result=chat_message.tool_call.tool_result,
        )
        if chat_message.tool_call
        else None,
        alternate_assistant_id=chat_message.alternate_assistant_id,
        overridden_model=chat_message.overridden_model,
    )

    return chat_msg_detail