src/shared/color.ts

import type { ColorAlleles, Hsv, Rgb } from './types';

export function clampByte(value: number): number {
  return Math.max(0, Math.min(255, Math.trunc(value)));
}

export function hsvToRgb(hueDeg: number, saturation: number, value: number): Rgb {
  const h = (((hueDeg % 360) + 360) % 360) / 60;
  const c = value * saturation;
  const x = c * (1 - Math.abs((h % 2) - 1));
  const m = value - c;
  let r = 0;
  let g = 0;
  let b = 0;

  if (h < 1) {
    r = c;
    g = x;
  } else if (h < 2) {
    r = x;
    g = c;
  } else if (h < 3) {
    g = c;
    b = x;
  } else if (h < 4) {
    g = x;
    b = c;
  } else if (h < 5) {
    r = x;
    b = c;
  } else {
    r = c;
    b = x;
  }

  return [
    clampByte((r + m) * 255),
    clampByte((g + m) * 255),
    clampByte((b + m) * 255),
  ];
}

export function rgbToHsv(rgb: Rgb): Hsv {
  const [r, g, b] = rgb.map((channel) => channel / 255) as Rgb;
  const max = Math.max(r, g, b);
  const min = Math.min(r, g, b);
  const delta = max - min;
  let hue = 0;

  if (delta !== 0) {
    if (max === r) {
      hue = 60 * (((g - b) / delta) % 6);
    } else if (max === g) {
      hue = 60 * ((b - r) / delta + 2);
    } else {
      hue = 60 * ((r - g) / delta + 4);
    }
  }

  return [((hue % 360) + 360) % 360, max === 0 ? 0 : delta / max, max];
}

export function expressedRgbFromAlleles(hsvAlleles: ColorAlleles): Rgb {
  const hue = (hsvAlleles.Hue[0] + hsvAlleles.Hue[1]) / 2;
  const saturation = (hsvAlleles.Saturation[0] + hsvAlleles.Saturation[1]) / 2;
  const value = (hsvAlleles.Value[0] + hsvAlleles.Value[1]) / 2;
  return hsvToRgb(hue, saturation, value);
}

export function derivePlantColor(budRgb: Rgb, leafRgb: Rgb): Rgb {
  const bud = rgbToHsv(budRgb);
  const leaf = rgbToHsv(leafRgb);
  return hsvToRgb(
    (bud[0] + leaf[0]) / 2,
    (bud[1] + leaf[1]) / 2,
    (bud[2] + leaf[2]) / 2
  );
}

export function hueFromRgb(rgb: Rgb): number {
  return Math.round(rgbToHsv(rgb)[0] * 10) / 10;
}

export function vibrance(rgb: Rgb): number {
  const [red, green, blue] = rgb;
  return Math.round(((Math.max(red, green, blue) - Math.min(red, green, blue)) / 255) * 1000) / 10;
}

export function colorFamily(hue: number): string {
  if (hue < 15 || hue >= 330) return 'red';
  if (hue < 40) return 'orange';
  if (hue < 70) return 'yellow';
  if (hue < 160) return 'green';
  if (hue < 200) return 'cyan';
  if (hue < 260) return 'blue';
  if (hue < 290) return 'purple';
  return 'magenta';
}