package main;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Couch {
    public static void main(final String... args) {
        final float original = 800;
        final float dpm = .02f;

        final List<Person> people = new ArrayList<>(6);
        people.add(new Person("Pato", 0, 23, 200));
        people.add(new Person("Ryan", 0, 11, 200));
        people.add(new Person("Jpo", 0, 15, 200));
        people.add(new Person("Haoyi", 0, 17, 200));
        people.add(new Person("Aedhan", 11, 23));
        people.add(new Person("Rando", 17, 23));

        final int startMonth = people.stream().mapToInt(p -> p.start).min().getAsInt();
        final int endMonth = people.stream().mapToInt(p -> p.end).max().getAsInt();

        float currValue = original;
        for (int i = startMonth; i <= endMonth; i++) {
            currValue = currValue - original * dpm;
            final int month = i;

            final List<Person> peopleLeaving = people
                    .stream()
                    .filter(p -> month != endMonth && p.end == month)
                    .collect(Collectors.toList());

            final List<Person> peopleComingIn = people
                    .stream()
                    .filter(p -> month != startMonth && p.start == month)
                    .collect(Collectors.toList());

            final List<Person> peopleThatWereThere = people
                    .stream()
                    .filter(p -> month > p.start && month <= p.end)
                    .collect(Collectors.toList());

            final List<Person> peoplePaying = peopleThatWereThere
                    .stream()
                    .filter(p -> !peopleLeaving.contains(p))
                    .collect(Collectors.toList());

            final float valuePerPerson = currValue / peopleThatWereThere.size();

            if (peopleLeaving.size() > 0 || peopleComingIn.size() > 0 && month != 0)  {
                System.out.printf("\nValue at month: %d is : $%.2f. Per Person: %.2f\n",
                        i, currValue, valuePerPerson);
                System.out.println("Leaving: " + peopleLeaving.stream()
                        .map(p -> p.name).collect(Collectors.toList()));
            }

            peopleLeaving.forEach(personLeaving -> {
                final float toPay = valuePerPerson / peoplePaying.size();
                peoplePaying.forEach(personPaying -> {
                    personPaying.paid += toPay;
                    personLeaving.got += toPay;
                    System.out.printf("%s pays %s total of $%.2f\n",
                            personPaying.name, personLeaving.name, toPay);
                });
            });

            final List<Person> peopleToPay = people
                    .stream()
                    .filter(p -> !peopleComingIn.contains(p))
                    .filter(p -> month >= p.start && month < p.end)
                    .collect(Collectors.toList());

            peopleComingIn.forEach(personComingIn -> {
                final float toPay = valuePerPerson / peopleToPay.size();
                peopleToPay.forEach(personStaying -> {
                    personStaying.got += toPay;
                    personComingIn.paid += toPay;
                    System.out.printf("%s pays %s total of $%.2f\n",
                            personComingIn.name, personStaying.name, toPay);
                });
            });

        }

        System.out.println("\n\nFinal Results: ");
        people.forEach(person ->
                System.out.printf("- %8s\tpaid:\t$%.2f\tgot:\t$%.2f\tfor a total paid of:\t$%.2f\n",
                        person.name,
                        person.paid,
                        person.got,
                        person.paid - person.got));
    }

    final class Person {
        final int start;
        final int end;
        final String name;

        float paid;
        float got;

        Person(final String name, final int start, final int end) {
            this(name, start, end, 0);
        }

        @Override
        public boolean equals(final Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            final Person person = (Person) o;

            if (start != person.start) return false;
            if (end != person.end) return false;
            return name.equals(person.name);
        }

        @Override
        public int hashCode() {
            int result = start;
            result = 31 * result + end;
            result = 31 * result + name.hashCode();
            return result;
        }

        @Override
        public String toString() {
            return "Person{" +
                    "name='" + name + '\'' +
                    ", paid=" + paid +
                    ", got=" + got +
                    ", net=" + (paid - got) +
                    '}';
        }

        Person(final String name, final int start, final int end, final float paid) {
            this.name = name;
            this.start = start;
            this.end = end;
            this.paid = paid;
            this.got = 0;
        }
    }
}