#!/usr/bin/env perl6
use v6;
#basic SI(International System of Units) type 


role MetricPrefix {
	method baseOn ( Str $base , Numeric $input ) {
		given $base {
			when 'pico' { return $input * 10**-12 }
			when 'namo' { return $input * 10**-9 }
			when 'micro' { return $input * 10**-6}
			when 'milli' { return $input * 10**-3 }
			when 'centi' { return $input * 10**-2 }
			when 'hecto' { return $input * 10**2 }
			when 'kilo' { return $input * 10**3 }
			when 'mega' { return $input * 10**6 }
			when 'giga' { return $input * 10**9 }
			when 'tera' { return $input * 10**12 }
			default { fail "you must input a metric prefix which allow pico to tera" }
		}
	}
}



class Mass does MetricPrefix {
	#basic Mass is g is different form si statda
	has $.g;

	submethod BUILD ( :$!g  ) {
	}

}

class Length does MetricPrefix {
	has $.Length ;
	
	submethod BUILD ( :$!Length  ) {
	}
}



multi postfix:<(kg)>( $input ) {
	return Mass.new( g => Mass.baseOn("kilo",$input) ) or fail "you Must input a number";
}

multi postfix:<(g)>( $input ) {
	return Mass.new( g => $input ) or fail "you Must input a number";
}

multi infix:<+>( Mass $inputOne , Mass $inputTwo ) is assoc<right> {
	return Mass.new( g => $inputOne.g + $inputTwo.g) or fail "error in there ";
}

multi infix:<->( Mass $inputOne , Mass $inputTwo ) is assoc<right> {
	return Mass.new( g => $inputOne.g - $inputTwo.g) or fail "error in there ";
}

multi infix:<*>( Mass $inputOne , Mass $inputTwo ) is assoc<right> is tighter( &infix:<+> ) is tighter( &infix:<-> ) is tighter( &infix:</>) {
	return Mass.new( g => $inputOne.g * $inputTwo.g) or fail "error in there ";
}

multi infix:</>( Mass $inputOne , Mass $inputTwo ) is assoc<right> is tighter( &infix:<+> ) is tighter( &infix:<-> )  {
	return Mass.new( g => $inputOne.g / $inputTwo.g) or fail "error in there ";
}





#the meterLeng
multi postfix:<(km)>( $input ) {
	return Length.new( Length => Length.baseOn("kilo",$input) ) or fail "you Must input a number";
}

multi postfix:<(m)>( $input ) {
	return Length.new( Length => $input ) or fail "you Must input a number";
}

multi infix:<+>( Length $inputOne , Length $inputTwo ) is assoc<right> {
	return Length.new( Length => $inputOne.Length + $inputTwo.Length) or fail "error in there ";
}

multi infix:<->( Length $inputOne , Length $inputTwo ) is assoc<right> {
	return Length.new( Length => $inputOne.Length - $inputTwo.Length) or fail "error in there ";
}

multi infix:<*>( Length $inputOne , Length $inputTwo ) is assoc<right> is tighter( &infix:<+> ) is tighter( &infix:<-> ) is tighter( &infix:</>) {
	return Length.new( Length => $inputOne.Length * $inputTwo.Length) or fail "error in there ";
}

multi infix:</>( Length $inputOne , Length $inputTwo ) is assoc<right> is tighter( &infix:<+> ) is tighter( &infix:<-> )  {
	return Length.new( Length => $inputOne.Length / $inputTwo.Length) or fail "error in there ";
}


#just a test
say 10(kg) + 1(g);
say 10(m) + 1(m);