main.js

(function(global, factory) {
  if(typeof exports === 'object' && typeof module !== 'undefined') {
    // CommonJS (Node.js)
    module.exports = factory();
  }
  else if(typeof define === 'function' && define.amd) {
    // AMD
    define([], factory);
  }
  else {
    // Browser Globals
    global.ccc = factory();
  }
})(this, function() {
  /**
   * Colour Code Converter
   * 
   * @param {string | number | Array<string | number>} arg1 Colour Code or RGB Codes String or RGB Code Array
   * @param {string | number} arg2 Green Colour or undefined
   * @param {string | number} arg3 Blue Colour or undefined
   * @return {string | Array<number>} Colour Code or RGB Codes or null : ex. '#1f2a3c' or 'rgb(15, 255, 0)'
   */
  function ccc(arg1, arg2, arg3) {
    if(arg1 && !arg2 && !arg3) {
      // One Argument
      if(typeof arg1 === 'string' && isColourCode(arg1)) {
        // Colour Code
        const parsed = beautifyColourCode(arg1);
        return colourCodeToRGBCode(parsed);
      }
      else if(isRGBCode(arg1)) {
        // RGB Code
        const parsed = beautifyRGBCode(arg1);
        return rgbCodeToColourCode(parsed);
      }
    }
    else if(arg1 && arg2 && arg3 && isRGBCode(arg1, arg2, arg3)) {
      // Three Arguments : RGB Code
      const parsed = beautifyRGBCode(arg1, arg2, arg3);
      return rgbCodeToColourCode(parsed);
    }
    
    // Invalid Values
    return null;
  }
  
  return ccc;
  
  /**
   * Is Colour Code
   * 
   * @param {string} input Input string
   * @return {boolean} true if the argument is valid colour code
   */
  function isColourCode(input) {
    // Lower Case
    input = `${input}`.toLowerCase();
    
    // Remove Sharp
    if(input.startsWith('#')) {
      input = input.slice(1);
    }
    
    // Invalid Length
    if(input.length !== 3 && input.length !== 6) {
      return false;
    }
    
    // Contains Invalid Clour Code Characters
    return input === input.replace(/[^0-9a-f]/g, '');
  }
  
  /**
   * Is RGB Code
   * 
   * @param {string | number} arg1 Argument 1 : RGB Codes or Red Colour
   * @param {string | number} arg2 Argument 2 : Green Colour or undefined
   * @param {string | number} arg3 Argument 3 : Blue Colour or undefined
   * @return {boolean} true if the arguments are valid RGB code
   */
  function isRGBCode(arg1, arg2, arg3) {
    if(arg1 && !arg2 && !arg3) {
      // "ccc 10,255,30"
      const array = `${arg1}`.split(',');
      
      // Invalid Length
      if(array.length !== 3) {
        return false;
      }
      
      // Every Arguments Are Valid?
      return array.every((input) => {
        return isValidRGBCode(input);
      });
    }
    else if(arg1 && arg2 && arg3) {
      // "ccc 10, 255, 30" or "ccc 10 255 30"
      return isValidRGBCode(arg1) && isValidRGBCode(arg2) && isValidRGBCode(arg3);
    }
    else {
      // Invalid Arguments Length
      return false;
    }
    
    /**
     * Is Valid RGB Code
     * 
     * @param {string | number} input Input String
     * @return {boolean} true if the input is valid RGB code
     */
    function isValidRGBCode(input) {
      // Remove Comma And Space
      input = `${input}`.replace(/,/g, '').trim();
      return input >= 0 && input <= 255;
    }
  }
  
  /**
   * Beautify Colour Code
   * 
   * @param {string} input Input string
   * @return {string} beautified colour code : ex. '39c' -> '3399cc'
   */
  function beautifyColourCode(input) {
    // Lower Case
    input = `${input}`.toLowerCase();
    
    // Remove Sharp
    if(input.startsWith('#')) {
      input = input.slice(1);
    }
    
    // Fix Shorthand : ex. '39c' => '3399cc'
    if(input.length === 3) {
      input = input
        .split('')
        .map((str) => {
          return str.repeat(2);
        })
        .join('');
    }
    
    return input;
  }
  
  /**
   * Beautify RGB Code
   * 
   * @param {string | number} arg1 Argument 1 : RGB Codes or Red Colour
   * @param {string | number} arg2 Argument 2 : Green Colour or undefined
   * @param {string | number} arg3 Argument 3 : Blue Colour or undefined
   * @return {Array<string | number>} beautified RGB codes array : ex. '15, 255, 0' -> [15, 255, 0]
   */
  function beautifyRGBCode(arg1, arg2, arg3) {
    if(arg1 && !arg2 && !arg3) {
      return `${arg1}`.split(',');
    }
    else {
      return [
        `${arg1}`.replace(/,/g, '').trim(),
        `${arg2}`.replace(/,/g, '').trim(),
        `${arg3}`.replace(/,/g, '').trim()
      ];
    }
  }
  
  /**
   * Colour Code To RGB Code
   * 
   * @param {string} code Colour Code : ex. '1f2a3c'
   * @return {Array<string | number>} RGB codes array : ex. [15, 255, 0]
   */
  function colourCodeToRGBCode(code) {
    const codeR = `${code}`.substr(0, 2);
    const codeG = `${code}`.substr(2, 2);
    const codeB = `${code}`.substr(4, 2);
    const r = parseInt(codeR, 16);
    const g = parseInt(codeG, 16);
    const b = parseInt(codeB, 16);
    return [r, g, b];
  }
  
  /**
   * RGB Code To Colour Code
   * 
   * @param {Array<string | number>} rgb RGB Code Array : ex. [15, 255, 0]
   * @return {string} Colour code : ex. '#1f2a3c'
   */
  function rgbCodeToColourCode(rgb) {
    const codeR = decimalToHex(rgb[0]);
    const codeG = decimalToHex(rgb[1]);
    const codeB = decimalToHex(rgb[2]);
    return `#${codeR}${codeG}${codeB}`;
    
    /**
     * Decimal To Hex
     * 
     * @param {string | number} decimal Decimal value : ex. 10
     * @return {string} hex value : ex. '0a'
     */
    function decimalToHex(decimal) {
      let hex = Number(decimal).toString(16);
      return `0${hex}`.substr(-2);
    }
  }  
});