flow like the river

VISUALIZACION/node_modules/polished/lib/internalHelpers/_hslToRgb.js.flow

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+// @flow
+
+type ConversionFunction = (red: number, green: number, blue: number) => string
+
+function colorToInt(color: number): number {
+  return Math.round(color * 255)
+}
+
+function convertToInt(red: number, green: number, blue: number): string {
+  return `${colorToInt(red)},${colorToInt(green)},${colorToInt(blue)}`
+}
+
+function hslToRgb(
+  hue: number,
+  saturation: number,
+  lightness: number,
+  convert: ConversionFunction = convertToInt,
+): string {
+  if (saturation === 0) {
+    // achromatic
+    return convert(lightness, lightness, lightness)
+  }
+
+  // formulae from https://en.wikipedia.org/wiki/HSL_and_HSV
+  const huePrime = (((hue % 360) + 360) % 360) / 60
+  const chroma = (1 - Math.abs(2 * lightness - 1)) * saturation
+  const secondComponent = chroma * (1 - Math.abs((huePrime % 2) - 1))
+
+  let red = 0
+  let green = 0
+  let blue = 0
+
+  if (huePrime >= 0 && huePrime < 1) {
+    red = chroma
+    green = secondComponent
+  } else if (huePrime >= 1 && huePrime < 2) {
+    red = secondComponent
+    green = chroma
+  } else if (huePrime >= 2 && huePrime < 3) {
+    green = chroma
+    blue = secondComponent
+  } else if (huePrime >= 3 && huePrime < 4) {
+    green = secondComponent
+    blue = chroma
+  } else if (huePrime >= 4 && huePrime < 5) {
+    red = secondComponent
+    blue = chroma
+  } else if (huePrime >= 5 && huePrime < 6) {
+    red = chroma
+    blue = secondComponent
+  }
+
+  const lightnessModification = lightness - chroma / 2
+  const finalRed = red + lightnessModification
+  const finalGreen = green + lightnessModification
+  const finalBlue = blue + lightnessModification
+  return convert(finalRed, finalGreen, finalBlue)
+}
+
+export default hslToRgb