function cz_validateHex(hex) {
  return /(^#?[0-9A-F]{6}$)|(^#?[0-9A-F]{3}$)/i.test(hex);
}

function cz_validateHsl(hsl) {
  return /(^hsl[(]\s*0*(?:[12]?\d{1,2}|3(?:[0-5]\d|60))\s*(?:\s*,\s*0*(?:\d\d?(?:\.\d+)?\s*%|\.\d+\s*%|100(?:\.0*)?\s*%)){2}\s*[)]$)/i.test(hsl);
}

function cz_validateRgb(rgb) {
  return /(^(?:(?:^|,\s*)([01]?\d\d?|2[0-4]\d|25[0-5])){3}$)/i.test(rgb);
}

function helper_hsl2hex(v1, v2, vh) { //to be used width hsl2hex();

  if (vh < 0) {
    vh += 1;
  };

  if (vh > 1) {
    vh -= 1;
  };

  if ((6 * vh) < 1) {
    return (v1 + (v2 - v1) * 6 * vh);
  };

  if ((2 * vh) < 1) {
    return (v2);
  };

  if ((3 * vh) < 2) {
    return (v1 + (v2 - v1) * ((2 / 3 - vh) * 6));
  };

  return v1;

}

function cz_getHslRy(hsl) {
  hsl = hsl.slice(4);
  hsl = hsl.split(")");
  hslRy = hsl[0].split(",");
  return hslRy.map(function(c) {
    return c.replace("%", "");
  })
}

function cz_hsl2rgb(hsl) { //hsl($h,$s%,$l%);
  var hslRy = getHslRy(hsl);
  h = hslRy[0] / 360;
  s = hslRy[1] / 100;
  l = hslRy[2] / 100;

  if (s == 0) //gray
  {
    r = l * 255;
    g = l * 255;
    b = l * 255;
  } else {
    if (l < 0.5) //dark
    {
      v2 = l * (1 + s);
    } else //light
    {
      v2 = (l + s) - (s * l);
    };

    v1 = 2 * l - v2;

    r = 255 * helper_hsl2hex(v1, v2, h + (1 / 3));
    g = 255 * helper_hsl2hex(v1, v2, h);
    b = 255 * helper_hsl2hex(v1, v2, h - (1 / 3));

  }

  return [r, g, b];
  /*OK*/
} //console.log(hsl2rgb("hsl(45,100%,50%)"))

function cz_hex2rgb(hexColor) {

  hexColor = hexColor.replace("#", "");
  if (hexColor.length == 6) {

    var redhex = hexColor.substr(0, 2);
    var greenhex = hexColor.substr(2, 2);
    var bluehex = hexColor.substr(4, 2);
  } else if (hexColor.length == 3) {
    var redhex = hexColor.substr(0, 1) + hexColor.substr(0, 1);
    var greenhex = hexColor.substr(1, 1) + hexColor.substr(1, 1);
    var bluehex = hexColor.substr(2, 1) + hexColor.substr(2, 1);
  }
  console.log(redhex);

  var rgbRy = [];

  rgbRy[0] = parseInt(redhex, 16);

  rgbRy[1] = parseInt(greenhex, 16);

  rgbRy[2] = parseInt(bluehex, 16);

  return rgbRy; /*OK*/
} //console.log(hex2rgb("ffbf00"))

function cz_rgb2rgb(rgb) {
  rgb = rgb.slice(4);
  rgb = rgb.split(")");
  rgbRy = rgb[0].split(",");
  return rgbRy.map(function(c) {
    return parseInt(c);
  });
} //console.log(rgb2rgb("rgb(255,191,0)"))

function cz_whatColor(str) {
  if (cz_validateHsl(str)) {
    return cz_hsl2rgb(str);
  } else if (cz_validateRgb(str)) {
    return cz_rgb2rgb(str);
  } else if (cz_validateHex(str)) {
    return cz_hex2rgb(str);
  } else {
    return ([255, 255, 255]);
  }
}

/* LEA VEROU https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html*/
function cz_getRelativeLuminance(rgb) { //relative luminance
  var rgb = rgb.map(function(c) {
    c /= 255;
    return c < .03928 ? c / 12.92 : Math.pow((c + .055) / 1.055, 2.4);

  });

  return (21.26 * rgb[0] + 71.52 * rgb[1] + 7.22 * rgb[2]) / 100
}

function cz_colorContrast(c1, c2) {
  var l1 = cz_getRelativeLuminance(c1);
  var l2 = cz_getRelativeLuminance(c2);
  var ret = (l1 + .05) / (l2 + .05);
  // 0.05 for not dividing with 0
  return ret < 1 ? 1 / ret : ret;
}

var normal = document.querySelector(".normal");
var large = document.querySelector(".large");
var el = document.querySelector(".el");
var output = document.querySelector(".output");
var inputBackground = document.querySelector(".c1")
var inputText = document.querySelector(".c2")
var backgroundColor = inputBackground.value;
var textColor = inputText.value;
var c1 = cz_whatColor(backgroundColor);
var c2 = cz_whatColor(textColor);

function cz_getContrast() {
  backgroundColor = inputBackground.value;
  textColor = inputText.value;
  c1 = cz_whatColor(backgroundColor);
  c2 = cz_whatColor(textColor);
  el.style.backgroundColor = "rgb(" + c1[0] + "," + c1[1] + "," + c1[2] + ")";
  el.style.color = "rgb(" + c2[0] + "," + c2[1] + "," + c2[2] + ")";
  large.innerHTML = "Para texto grande: ";
  normal.innerHTML = "Para texto normal: ";
  var cc = cz_colorContrast(c1, c2);

  output.innerHTML = parseFloat(cc).toFixed(1);
  if (cc >= 7) {
    large.innerHTML += " aprobado AAA";
    normal.innerHTML += " aprobado AAA";
    output.style.backgroundColor = "#6ab150";
    output.style.color = "#fff";
  } else if (cc >= 4.5 && cc < 7) {
    large.innerHTML += " aprobado AAA";
    normal.innerHTML += " aprobado AA";
    output.style.backgroundColor = "#ffff00";
    output.style.color = "#222";
  } else if (cc >= 3 && cc < 4.5) {
    large.innerHTML += " aprobado AA";
    normal.innerHTML += " falla";
    output.style.backgroundColor = "#ff7b00";
    output.style.color = "#fff";
  } else {
    large.innerHTML += " falla";
    normal.innerHTML += " falla";
    output.style.backgroundColor = "#dd0000";
    output.style.color = "#fff";
  }
}

window.addEventListener("load", cz_getContrast, false);
inputBackground.addEventListener("input", cz_getContrast, false);
inputText.addEventListener("input", cz_getContrast, false);