"""Nearest-match selection of a catalog record for a knob coordinate."""

from __future__ import annotations

import math
from dataclasses import dataclass

from hef.catalog import Record

SELECTOR_MODES = frozenset({"none", "audio", "video", "av"})
CONTENT_MODES = frozenset({"audio", "video", "av"})


@dataclass(frozen=True)
class Coordinate:
    left: int
    right: int
    dark: int
    light: int


@dataclass(frozen=True)
class Weights:
    brain: float = 1.0
    mood: float = 1.0


def distance(a: Coordinate, b: Coordinate, weights: Weights = Weights()) -> float:
    """Weighted Euclidean distance; brain plane and mood plane weighted separately."""
    brain_sq = (a.left - b.left) ** 2 + (a.right - b.right) ** 2
    mood_sq = (a.dark - b.dark) ** 2 + (a.light - b.light) ** 2
    return math.sqrt(weights.brain * brain_sq + weights.mood * mood_sq)


def record_coordinate(record: Record) -> Coordinate:
    """The (left, right, dark, light) coordinate of a catalog record."""
    return Coordinate(record.left, record.right, record.dark, record.light)