package lamda.first;

import lamda.userdefined.functional.interfaces.DoubleNumericArrayFunc;
import lamda.userdefined.functional.interfaces.StringFunc;

public class LamdaAsArgsDemo {
    public static void main(String[] args) throws EmptyArrayException{

        String inputStr = "Lamda adds power";
        String outStr;

        System.out.println("Input string is : " + inputStr);

        // parssing single line/singe method
        outStr = StringOper(String::toLowerCase, inputStr);
        System.out.println("Output String is : "+outStr);

        //passing block as function
        outStr =  StringOper(str->{
            String s="";
            for (int i=str.length()-1;i>=0;i--){
                s=s+str.charAt(i);
            }
            return s;
        },inputStr);
        System.out.println("Output String is :"+ outStr);

        //passing instance as functional parameter

        StringFunc strfuc = str -> {
            String s = "";
            for (int i = str.length() - 1; i >= 0; i--) {
                s = s + str.charAt(i);
            }
            return s;
        };

        outStr = StringOper(strfuc,"Hello World...");
        System.out.println("out put by Passing reference : "+outStr);

        //Lamda EXCEPTION DEMO
        double d[] = {1.0, 2.0, 3.0, 4.0, 5.0};
        DoubleNumericArrayFunc average = n-> {

            if(n.length ==0){
                throw new EmptyArrayException();
            }

            double sum = 0.0;
            for (int i=0; i<n.length; i++){
                sum = sum+n[i];
            }
            return sum;
        };
        System.out.println("Average of given values is : "+average.func(d));
        System.out.println("Average of given input is "+ average.func(new double[0]));


    }

    public static String StringOper(StringFunc sf, String s) {
        return sf.func(s);
    }
}