import ascb.units.Converter;

class ascb.units.Unit {

  private var _sUnitName:String;
  private var _sUnitCategory:String;
  private var _uBaseUnit:Unit;
  private var _nMultiplier:Number;
  private var _sLabelSingular:String;
  private var _sLabelPlural:String;

  public static function getCategories():Array {
    return ["angle", "temperature", "weightmass", "distance", "volume"];
  }

  public static function getUnits(sCategory:String):Array {
    var aAngle:Array = ["DEGREE", "RADIAN", "GRADIAN"];
    var aTemperature:Array = ["CELCIUS", "FAHRENHEIT", "KELVIN"];
    var aWeightMass:Array = ["OUNCE", "POUND", "TON", "MILLIGRAM", "GRAM", "KILOGRAM"];
    var aDistance:Array = ["CENTIMETER", "METER", "KILOMETER", "INCH", "FOOT", "MILE", "YARD"];
    var aVolume:Array = ["LITER", "GALLON"];
    aAngle.sort();
    aTemperature.sort();
    aWeightMass.sort();
    aDistance.sort();
    aVolume.sort();
    var aSum:Array = aAngle.concat(aTemperature, aWeightMass, aDistance, aVolume);
    switch (sCategory) {
      case "angle":
        return aAngle;
      case "temperature":
        return aTemperature;
      case "weightmass":
        return aWeightMass;
      case "distance":
        return aDistance;
      case "volume":
        return aVolume;
      default:
        return aSum;
    }
  }

  public static function get DEGREE():Unit {
    return new Unit("degree", "angle");
  }

  public static function get RADIAN():Unit {
    return new Unit("radian", "angle");
  }

  public static function get GRADIAN():Unit {
    return new Unit("gradian", "angle");
  }

  public static function get CELCIUS():Unit {
    return new Unit("celcius", "temperature", null, null, "celcius", "celcius");
  }

  public static function get FAHRENHEIT():Unit {
    return new Unit("fahrenheit", "temperature", null, null, "fahrenheit", "fahrenheit");
  }

  public static function get KELVIN():Unit {
    return new Unit("kelvin", "temperature", null, null, "kelvin", "kelvin");
  }

  public static function get OUNCE():Unit {
    return new Unit("ounce", "weightmass", POUND, 1/16);
  }

  public static function get POUND():Unit {
    return new Unit("pound", "weightmass");
  }

  public static function get TON():Unit {
    return new Unit("ton", "weightmass", POUND, 2000);
  }

  public static function get MILLIGRAM():Unit {
    return new Unit("milligram", "weightmass", GRAM, .001);
  }

  public static function get GRAM():Unit {
    return new Unit("gram", "weightmass");
  }  

  public static function get KILOGRAM():Unit {
    return new Unit("kilogram", "weightmass", GRAM, 1000);
  }

  public static function get LITER():Unit {
    return new Unit("liter", "volume");
  }

  public static function get GALLON():Unit {
    return new Unit("gallon", "volume");
  }

  public static function get INCH():Unit {
    return new Unit("inch", "distance", FOOT, 1/12, "inch", "inches");
  }

  public static function get FOOT():Unit {
    return new Unit("foot", "distance", null, null, "foot", "feet");
  }

  public static function get YARD():Unit {
    return new Unit("yard", "distance", FOOT, 3);
  }

  public static function get MILE():Unit {
    return new Unit("mile", "distance", FOOT, 5280);
  }

  public static function get CENTIMETER():Unit {
    return new Unit("centimeter", "distance", METER, .01);
  }

  public static function get METER():Unit {
    return new Unit("meter", "distance");
  }

  public static function get KILOMETER():Unit {
    return new Unit("kilometer", "distance", METER, 1000);
  }

  public function get name():String {
    return _sUnitName;
  }

  public function get category():String {
    return _sUnitCategory;
  }

  public function get baseUnit():Unit {
    return _uBaseUnit;
  }

  public function get multiplier():Number {
    return _nMultiplier;
  }

  public function get label():String {
    return _sLabelSingular;
  }

  public function get labelPlural():String {
    return _sLabelPlural;
  }

  function Unit(sUnitName:String, sUnitCategory:String, uBaseUnit:Unit, nMultiplier:Number, sLabelSingular:String, sLabelPlural:String) {
    _sUnitName = sUnitName;
    _sUnitCategory = sUnitCategory;
    _uBaseUnit = (uBaseUnit == undefined) ? this : uBaseUnit;
    _nMultiplier = (nMultiplier == undefined) ? 1 : nMultiplier;
    _sLabelSingular = (sLabelSingular == undefined) ? sUnitName : sLabelSingular;
    _sLabelPlural = (sLabelPlural == undefined) ? _sLabelSingular + "s" : sLabelPlural;
  }

  public function getConverterTo(uUnit:Unit):Converter {
    if(uUnit.category != _sUnitCategory) {
      return null;
    }
    else {
      return new Converter(this, uUnit);
    }
  }

  public function getConverterFrom(uUnit:Unit):Converter {
    if(uUnit.category != _sUnitCategory) {
      return null;
    }
    else {
      return new Converter(uUnit, this);
    }
  }

}