"""历史 session 目录：列表 + 导出为用户轮次列表（用于评测快照）。"""

from __future__ import annotations

from dataclasses import dataclass

from sqlalchemy.ext.asyncio import AsyncSession

from app.features.evaluation.schemas import (
    SessionDialogueMessageOut,
    SessionDialogueOut,
)
from app.features.evaluation.session_catalog_repo import SessionCatalogRepo


@dataclass
class SessionSummary:
    id: str
    user_id: str
    user_phone: str | None
    started_at: object | None
    last_message_at: object | None
    conversation_stage: str | None
    current_topic: str | None
    status: str | None


@dataclass
class SessionTranscript:
    conversation_id: str
    user_id: str
    user_utterances_from_segments: list[str]
    user_utterances_from_messages: list[str]


class SessionCatalogService:
    def __init__(self, db: AsyncSession) -> None:
        self._repo = SessionCatalogRepo(db)

    async def list_sessions(
        self,
        *,
        offset: int = 0,
        limit: int = 50,
        user_id: str | None = None,
        q: str | None = None,
        status: str | None = None,
    ) -> tuple[list[SessionSummary], int]:
        total = await self._repo.count_conversations(status=status)
        rows = await self._repo.list_conversations(
            offset=offset,
            limit=limit,
            user_id=user_id,
            q_text=q,
            status=status,
        )
        out = [
            SessionSummary(
                id=c.id,
                user_id=c.user_id,
                user_phone=c.user.phone if c.user is not None else None,
                started_at=c.started_at,
                last_message_at=c.last_message_at,
                conversation_stage=c.conversation_stage,
                current_topic=c.current_topic,
                status=c.status,
            )
            for c in rows
        ]
        return out, total

    async def get_session_dialogue(
        self, conversation_id: str
    ) -> SessionDialogueOut | None:
        c = await self._repo.get_conversation(conversation_id)
        if not c or c.deleted_at:
            return None
        msgs = await self._repo.list_messages_for_conversation(conversation_id)
        return SessionDialogueOut(
            conversation_id=conversation_id,
            messages=[
                SessionDialogueMessageOut(
                    role=m.role,
                    content=m.content,
                    created_at=m.created_at,
                )
                for m in msgs
            ],
        )

    async def get_transcript(self, conversation_id: str) -> SessionTranscript | None:
        c = await self._repo.get_conversation(conversation_id)
        if not c or c.deleted_at:
            return None
        segs = await self._repo.list_segments_for_conversation(conversation_id)
        msgs = await self._repo.list_messages_for_conversation(conversation_id)
        from_segments = [
            (s.user_input_text or "").strip()
            for s in segs
            if (s.user_input_text or "").strip()
        ]
        from_messages = [
            m.content.strip()
            for m in msgs
            if m.role == "human" and (m.content or "").strip()
        ]
        return SessionTranscript(
            conversation_id=c.id,
            user_id=c.user_id,
            user_utterances_from_segments=from_segments,
            user_utterances_from_messages=from_messages,
        )