from pydantic import BaseModel, Field


class LearningAssistantSessionCreateRequest(BaseModel):
    """学习助手会话创建请求：进入 AI 学习助手页面时初始化短期问答会话。"""

    title: str | None = Field(default=None, max_length=100, description="会话标题，前端可不传")


class LearningAssistantSessionResponse(BaseModel):
    """学习助手会话响应：返回前端后续流式问答需要使用的会话 ID。"""

    assistant_session_id: str
    user_id: str
    institution_id: int | None = None
    institution_name: str | None = None
    title: str
    status: str
    created_at: str
    updated_at: str
    expires_in_seconds: int


class LearningAssistantChatRequest(BaseModel):
    """学习助手问答请求：普通用户面向机构知识库提出医学学习问题。"""

    question: str = Field(..., min_length=1, max_length=1000, description="用户问题")
    top_k: int | None = Field(default=None, ge=1, le=10, description="最终返回给 LLM 的来源片段数")
    score_threshold: float | None = Field(default=None, ge=0, le=1, description="向量相似度过滤阈值")


class LearningAssistantSource(BaseModel):
    """学习助手来源：记录 PDF 文档、页码和引用片段。"""

    document_id: int
    document_title: str | None = None
    file_name: str
    page_start: int
    page_end: int
    chunk_uid: str
    score: float
    quote: str