from datetime import datetime
from typing import Literal, Optional

from pydantic import BaseModel, Field, model_validator


# ---------- 局部块更新 ----------

class BlockUpdate(BaseModel):
    level: int = Field(..., ge=1, le=6)
    index: int = Field(..., ge=0)
    content: str


# ---------- 请求 ----------

class CreateDocumentRequest(BaseModel):
    user_id: str = Field(..., alias="userId")
    file_url: str = Field(..., alias="fileUrl")
    session_id: str = Field(..., alias="sessionId")

    model_config = {"populate_by_name": True}


class UpdateDocumentRequest(BaseModel):
    content: Optional[str] = None
    blocks: Optional[list[BlockUpdate]] = None

    @model_validator(mode="after")
    def check_content_or_blocks(self) -> "UpdateDocumentRequest":
        if self.content is not None and self.blocks is not None:
            raise ValueError("content 与 blocks 不能同时传入")
        return self


# ---------- 响应 ----------

class DocumentResponse(BaseModel):
    id: str
    content: str
    format: str
    session_id: str = Field(..., serialization_alias="sessionId")
    user_id: Optional[str] = Field(None, serialization_alias="userId")
    created_at: datetime = Field(..., serialization_alias="createdAt")
    updated_at: datetime = Field(..., serialization_alias="updatedAt")

    model_config = {"from_attributes": True, "populate_by_name": True}


class DocumentListItem(BaseModel):
    id: str
    session_id: str = Field(..., serialization_alias="sessionId")
    created_at: datetime = Field(..., serialization_alias="createdAt")
    updated_at: datetime = Field(..., serialization_alias="updatedAt")

    model_config = {"from_attributes": True, "populate_by_name": True}


class Pagination(BaseModel):
    page: int
    page_size: int = Field(..., serialization_alias="pageSize")
    total: int
    total_pages: int = Field(..., serialization_alias="totalPages")

    model_config = {"populate_by_name": True}