<?php

function hexToHsl($hex) {
  //Convert Value rrggbb to hsl.
  //Produces (HUE: in [0,1] of 360°, SAT: in [0,1], LIG: in [0,1])
  $hex = array($hex[0].$hex[1], $hex[2].$hex[3], $hex[4].$hex[5]);
  $rgb = array_map(function($part) {
    return hexdec($part) / 255;
  }, $hex);

  $max = max($rgb);
  $min = min($rgb);

  $l = ($max + $min) / 2;

  if ($max == $min) {
    $h = $s = 0;
  } else {
    $diff = $max - $min;
    $s = $l > 0.5 ? $diff / (2 - $max - $min) : $diff / ($max + $min);

    switch($max) {
    case $rgb[0]:
      $h = ($rgb[1] - $rgb[2]) / $diff + ($rgb[1] < $rgb[2] ? 6 : 0);
      break;
    case $rgb[1]:
      $h = ($rgb[2] - $rgb[0]) / $diff + 2;
      break;
    case $rgb[2]:
      $h = ($rgb[0] - $rgb[1]) / $diff + 4;
      break;
    }

    $h /= 6;
  }
  //TODO: Maybe return values not changed? For now this seems easier like so
  return array($h*360, $s*100, $l*100);
}

function hslToHex($hsl) {
  list($h, $s, $l) = $hsl;
  if ($s == 0) $s = 0.000001;

  $q = $l < 0.5 ? $l * (1 + $s) : $l + $s - $l * $s;
  $p = 2 * $l - $q;

  $r = hue2rgb($p, $q, $h + 1/3);
  $g = hue2rgb($p, $q, $h);
  $b = hue2rgb($p, $q, $h - 1/3);

  return rgb2hex($r) . rgb2hex($g) . rgb2hex($b);
}

function hue2rgb($p, $q, $t) {
  if ($t < 0) $t += 1;
  if ($t > 1) $t -= 1;
  if ($t < 1/6) return $p + ($q - $p) * 6 * $t;
  if ($t < 1/2) return $q;
  if ($t < 2/3) return $p + ($q - $p) * (2/3 - $t) * 6;

  return $p;
}

function rgb2hex($rgb) {
  return str_pad(dechex($rgb * 255), 2, '0', STR_PAD_LEFT);
}


function getColor($name,$default){
  // Color Picker can be tricked: 1. Select color; 2. delete color in input field; 3. Publish.
  // In this case an empty value is set but the default value is not used.
  //Get color from the Customizer in the form #rrggbb 
  $colsharp = esc_attr(get_theme_mod($name, $default)) ? esc_attr(get_theme_mod($name, $default)) : $default;
  // delete the '#'  
  $hex = substr($colsharp,1);

  return hexToHsl($hex);
}