(function() {
/***
 * Calculate the time reset code for Pokémon Crystal.
 * 
 * Purpose: Take the trainer's name, currently held cash, and ID
 *   number, returning a five digit ID number. 
 * 
 *  1) Map the first five characters of the trainer's name to an
 *     arbitrary set of numbers.
 *  2) Add those values together to get a single value.
 *  3) If the current cash is greater than 65535, get the modulus.
 *  4) Integer divide the current cash or modulus by 256.
 *  5) Add the modulus of that number and 256 to the result of the
 *     previous step.
 *  6) If the ID is greater than 65535, subtract the current
 *     cash from the ID until it is less than 65535.
 *  7) Integer divide the ID number or modulus by 256. 
 *  8) Add the modulus of that number and 256 to the result of the
 *     previous step.
 *  9) Zero pad the result from each input.
 */

var CALC = CALC || {};

CALC.magicValue = 65535;
CALC.inputNames = ["name", "currentCash", "id"];
CALC.inputs = {};
CALC.values = {};
CALC.charMap = {
  // Uppercase
    "A": 128, "B": 129, "C": 130, "D": 131, "E": 132, "F": 133, "G": 134
  , "H": 135, "I": 136, "J": 137, "K": 138, "L": 139, "M": 140, "N": 141
  , "O": 142, "P": 143, "Q": 144, "R": 145, "S": 146, "T": 147, "U": 148
  , "V": 149, "W": 150, "X": 151, "Y": 152, "Z": 153
  // Lowercase
  , "a": 160, "b": 161, "c": 162, "d": 163, "e": 164, "f": 165, "g": 166
  , "h": 167, "i": 168, "j": 169, "k": 170, "l": 171, "m": 172, "n": 173
  , "o": 174, "p": 175, "q": 176, "r": 177, "s": 178, "t": 179, "u": 180
  , "v": 181, "w": 182, "x": 183, "y": 184, "z": 185
};

CALC.outputName = "password";

/***
 * Pad a number with zeroes or a given character by a given amount.
 * http://stackoverflow.com/a/10073788/2305229
 ***/
CALC.pad = function(n, width, z)
{
  z = z || '0';
  n = n + '';
  return n.length >= width ? n : new Array(width - n.length + 1).join(z) + n;
};

CALC.addHandlers = function(inputNames)
{
  for (var i = 0; i < inputNames.length; i++)
  {
    CALC.inputs[inputNames[i]] = document.getElementsByName(inputNames[i])[0];
    CALC.inputs[inputNames[i]].addEventListener(
         "keyup"
       , this.calculatePassword
       , false
     );
  }
};

CALC.getNameBasedValue = function(name)
{
  nameCharsLength = (name.length < 5 ? name.length : 5);
  nameChars = name.substring(0, nameCharsLength);
  nameVal = 0;
  for (var i = 0; i < nameCharsLength; i++)
  {
    nameVal = nameVal + CALC.charMap[nameChars[i]];
  }
  return nameVal;
};

CALC.getCashBasedValue = function(cash)
{
  cashVal = cash;
  if (CALC.magicValue < cash)
  {
    cashVal = cash % CALC.magicValue;
  }
  return ~~(cashVal/256) + cashVal % 256;
};

CALC.getIdBasedValue = function(id)
{
  idVal = CALC.adjustValueBelowThreshold(
        id
      , CALC.inputs.currentCash.value
      , CALC.magicValue
    );
  return ~~(idVal/256) + idVal % 256;
};

CALC.adjustValueBelowThreshold = function(value, adjustment, threshold)
{
  while (threshold < value)
  {
    value = value - adjustment;
  }
  return value;
};

CALC.calculatePassword = function(event)
{
  event.preventDefault;
  var password = 0;
  console.log(CALC.values.name);
  if (CALC.inputs.name.value.length > 0
    && CALC.inputs.currentCash.value.length > 0
    && CALC.inputs.id.value.length > 0)
  {
    CALC.values.name = CALC.getNameBasedValue(CALC.inputs.name.value);
    CALC.values.currentCash = CALC.getCashBasedValue(CALC.inputs.currentCash.value);
    CALC.values.id = CALC.getIdBasedValue(CALC.inputs.id.value);
    Object.keys(CALC.values).forEach(function(value) {
      password = password + CALC.values[value];
    });
    CALC.writePassword(password);
  }
};

CALC.writePassword = function(password)
{
  document.getElementsByName(this.outputName)[0].value = CALC.pad(password, 5);
};

CALC.init = function()
{
  this.addHandlers(this.inputNames);
  // document.getElementsByName("name")[0].focus();
};

CALC.init();
})();