from pydantic import BaseModel, ConfigDict, field_validator
from datetime import datetime
from typing import Literal, Optional

AccentColor = Literal["cyan", "blue", "green", "purple", "red", "orange", "pink", "yellow"]


def _validate_pin_length(v: str, label: str = "PIN") -> str:
    if len(v) < 4:
        raise ValueError(f'{label} must be at least 4 characters')
    if len(v) > 72:
        raise ValueError(f'{label} must be at most 72 characters')
    return v


class SettingsCreate(BaseModel):
    pin: str

    @field_validator('pin')
    @classmethod
    def pin_length(cls, v: str) -> str:
        return _validate_pin_length(v)


class SettingsUpdate(BaseModel):
    accent_color: Optional[AccentColor] = None
    upcoming_days: int | None = None
    preferred_name: str | None = None
    weather_city: str | None = None
    weather_lat: float | None = None
    weather_lon: float | None = None

    @field_validator('weather_lat')
    @classmethod
    def validate_lat(cls, v: float | None) -> float | None:
        if v is not None and (v < -90 or v > 90):
            raise ValueError('Latitude must be between -90 and 90')
        return v

    @field_validator('weather_lon')
    @classmethod
    def validate_lon(cls, v: float | None) -> float | None:
        if v is not None and (v < -180 or v > 180):
            raise ValueError('Longitude must be between -180 and 180')
        return v


class SettingsResponse(BaseModel):
    id: int
    accent_color: str
    upcoming_days: int
    preferred_name: str | None = None
    weather_city: str | None = None
    weather_lat: float | None = None
    weather_lon: float | None = None
    created_at: datetime
    updated_at: datetime

    model_config = ConfigDict(from_attributes=True)


class ChangePinRequest(BaseModel):
    old_pin: str
    new_pin: str

    @field_validator('new_pin')
    @classmethod
    def new_pin_length(cls, v: str) -> str:
        return _validate_pin_length(v, "New PIN")