package uk.co.drumcoder;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Test {
    public static void main(String[] args) {
        final List<Integer> testList = Arrays.asList(10, 7, 14, 1, 3, 3, 14);

        // stream of list
        final Stream<Integer> testStream = testList.stream();
        System.out.println("Stream");
        testStream.forEach((i) -> System.out.println(i));

        // ordered stream
        final Stream<Integer> sortedStream = testList.stream().sorted();
        System.out.println("Sorted Stream");
        sortedStream.forEach((i) -> System.out.println(i));

        // Find first item
        final Optional<Integer> firstItem = testList.stream().findFirst();
        if (firstItem.isPresent()) {
            System.out.println("First Item");
            System.out.println(firstItem.get());
        }

        // reversed stream
        final Stream<Integer> reversedStream = testList.stream().sorted(Collections.reverseOrder());
        System.out.println("Reverse Sorted");
        reversedStream.forEach(System.out::println);

        // doubled stream
        final Stream<Integer> doubledStream = testList.stream().sorted().map(e -> e * 2);
        System.out.println("Doubled Stream");
        doubledStream.forEach(System.out::println);

        // sum numbers in a stream using reduce
        final int startValue = 0;
        final Integer sum1 = testList.stream().reduce(startValue, (a, b) -> a + b);
        System.out.println("Sum of integers (reduce)");
        System.out.println(sum1);

        // sum numbers in stream using collect
        final Integer sum2 = testList.stream().collect(Collectors.summingInt(Integer::intValue));
        System.out.println("Sum of integers (collect)");
        System.out.println(sum2);

        // sum numbers using sum
        final Integer sum3 = testList.stream().mapToInt(Integer::intValue).sum();
        System.out.println("Sum of integers (sum)");
        System.out.println(sum3);

        // create list from stream
        final Stream<Integer> listStream = testList.stream().sorted();
        final List<Integer> streamList = listStream.collect(Collectors.toList());
        System.out.println("Stream to List");
        streamList.forEach(System.out::println);

        // create set from stream - remove duplicates
        final Stream<Integer> setStream = testList.stream().sorted();
        final Set<Integer> streamSet = setStream.collect(Collectors.toSet());
        System.out.println("Stream to Set");
        streamSet.forEach(System.out::println);

        // filter stream
        final Stream<Integer> lessThanTenStream = testList.stream().filter(n -> n < 10);
        System.out.println("Less Than Ten Stream");
        lessThanTenStream.forEach(System.out::println);
    }

}