from datetime import datetime
from uuid import UUID

from pydantic import BaseModel, ConfigDict, Field, field_validator

from .models import TaskStatus


class TaskBase(BaseModel):
    title: str = Field(min_length=1, max_length=200)
    description: str | None = Field(default=None, max_length=5000)
    status: TaskStatus = TaskStatus.pending
    due_at: datetime | None = None

    @field_validator("title")
    @classmethod
    def title_not_blank(cls, value: str) -> str:
        value = value.strip()
        if not value:
            raise ValueError("title must not be blank")
        return value


class TaskCreate(TaskBase):
    pass


class TaskUpdate(BaseModel):
    title: str | None = Field(default=None, min_length=1, max_length=200)
    description: str | None = Field(default=None, max_length=5000)
    status: TaskStatus | None = None
    due_at: datetime | None = None

    @field_validator("title")
    @classmethod
    def title_not_blank(cls, value: str | None) -> str | None:
        if value is not None:
            value = value.strip()
            if not value:
                raise ValueError("title must not be blank")
        return value


class TaskRead(TaskBase):
    id: UUID
    created_at: datetime
    updated_at: datetime
    model_config = ConfigDict(from_attributes=True)


class ErrorDetail(BaseModel):
    loc: list[str | int] = []
    msg: str
    type: str | None = None


class ErrorBody(BaseModel):
    code: str
    message: str
    details: list[ErrorDetail] = []


class ErrorResponse(BaseModel):
    error: ErrorBody