from datetime import datetime
from typing import Generic, TypeVar

from pydantic import BaseModel, ConfigDict, Field

T = TypeVar("T")


class Page(BaseModel, Generic[T]):
    items: list[T]
    total: int
    offset: int
    limit: int


class DocumentResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    filename: str
    file_type: str
    mime_type: str
    file_size: int
    status: str
    chunk_count: int
    error_code: str | None
    error_message: str | None
    created_at: datetime
    updated_at: datetime


class ChunkResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    document_id: str
    order_index: int
    content: str
    page_number: int | None
    char_count: int
    created_at: datetime


class Pagination(BaseModel):
    offset: int = Field(default=0, ge=0)
    limit: int = Field(default=20, ge=1, le=100)