from datetime import datetime
from typing import Optional
from pydantic import BaseModel, Field


class MaterialCreate(BaseModel):
    filename: str = Field(..., min_length=1, max_length=255)
    title: str = Field(..., min_length=1, max_length=200)
    material_type: str = "text"
    subject: str = ""
    grade: str = ""
    tags: list[str] = Field(default_factory=list)
    summary: str = ""
    char_count: int = 0
    size: int = 0
    source: str = "upload"


class MaterialUpdate(BaseModel):
    title: Optional[str] = None
    subject: Optional[str] = None
    grade: Optional[str] = None
    tags: Optional[list[str]] = None
    summary: Optional[str] = None
    status: Optional[str] = None


class MaterialOut(BaseModel):
    id: int
    user_id: int
    filename: str
    title: str
    material_type: str = "text"
    subject: str = ""
    grade: str = ""
    tags: list = Field(default_factory=list)
    summary: str = ""
    char_count: int = 0
    size: int = 0
    source: str = "upload"
    created_at: datetime | None = None
    updated_at: datetime | None = None

    model_config = {"from_attributes": True}