"""Scope: WHERE in time, depth, identity, and opacity the cursor extends."""
from __future__ import annotations
from dataclasses import dataclass
from typing import Optional, Union

import numpy as np


@dataclass(frozen=True, slots=True)
class FrameIndex:
    index: int


@dataclass(frozen=True, slots=True)
class FrameRange:
    start: int
    end: int


class _AllFrames:
    __slots__ = ()

    def __repr__(self) -> str:
        return "ALL_FRAMES"


ALL_FRAMES = _AllFrames()
TemporalScope = Union[FrameIndex, FrameRange, _AllFrames]


@dataclass(frozen=True, slots=True)
class DepthScope:
    layer_id: Optional[str] = None


@dataclass(frozen=True, slots=True, eq=False)
class OpacityProfile:
    kind: str = "hard"
    falloff: Optional[np.ndarray] = None


@dataclass(frozen=True, slots=True, eq=False)
class IdentityLock:
    embedding: np.ndarray
    source: str = ""