"""会话及对话轮次，用于多轮上下文和后续持久化"""

from datetime import datetime
from typing import Literal

from pydantic import BaseModel


class Turn(BaseModel):
    """一次任务对应一轮对话，同一个 thread_id 多次写入时覆盖同一轮"""

    conversation_id: str
    thread_id: str
    message_id: str
    prompt: str  # 用户原始输入
    outcome: Literal["completed", "waiting_for_input", "failed", "cancelled"]
    summary: str  # 助手一侧的完整回复（回答、追问或失败说明），不截断；不代表前端已执行
    created_at: datetime


class ConversationCreated(BaseModel):
    conversation_id: str


class ConversationDetail(BaseModel):
    conversation_id: str
    turns: list[Turn]


class ConversationSummary(BaseModel):
    """历史会话列表项，只包含已产生对话的会话"""

    conversation_id: str
    title: str  # 取自首轮用户输入，过长时截断
    updated_at: datetime  # 最近一轮对话的创建时间


class ConversationList(BaseModel):
    conversations: list[ConversationSummary]