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


class Priority(str, Enum):
    low = "low"
    medium = "medium"
    high = "high"


class TaskBase(BaseModel):
    title: str = Field(..., min_length=1, max_length=200)
    description: Optional[str] = None
    date: str = Field(..., pattern=r"^\d{4}-\d{2}-\d{2}$")
    time: Optional[str] = Field(None, pattern=r"^\d{2}:\d{2}$")
    priority: Priority = Priority.medium


class TaskCreate(TaskBase):
    pass


class TaskUpdate(BaseModel):
    title: Optional[str] = Field(None, min_length=1, max_length=200)
    description: Optional[str] = None
    date: Optional[str] = Field(None, pattern=r"^\d{4}-\d{2}-\d{2}$")
    time: Optional[str] = Field(None, pattern=r"^\d{2}:\d{2}$")
    priority: Optional[Priority] = None
    is_done: Optional[bool] = None


class TaskResponse(TaskBase):
    id: str
    is_done: bool
    created_at: Optional[datetime]
    updated_at: Optional[datetime]

    class Config:
        from_attributes = True


class RescheduleRequest(BaseModel):
    target_date: str = Field(..., pattern=r"^\d{4}-\d{2}-\d{2}$")


class HealthResponse(BaseModel):
    status: str = "ok"