"""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 Annotated, Literal

from pydantic import BaseModel, StringConstraints

from .base import NonBlankString

Title = Annotated[
    str, StringConstraints(strip_whitespace=True, min_length=1, max_length=100)
]


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 ConversationCreate(BaseModel):
    # 会话归属的大屏；不传则不归属任何大屏（兼容旧调用）
    screen_id: NonBlankString | None = None


class ConversationRename(BaseModel):
    title: Title


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  # 用户改过名用改的，否则取自首轮用户输入，过长时截断
    screen_id: str | None = None
    updated_at: datetime  # 最近一轮对话的创建时间


class ConversationList(BaseModel):
    conversations: list[ConversationSummary]
    total: int  # 符合条件的会话总数（不受 limit / offset 影响），管理页翻页用