package com.example;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.SpringApplication;
import org.springframework.web.bind.annotation.*;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;

import java.util.*;

@SpringBootApplication
@Controller
public class App {
    @RequestMapping("/")
    public String index(
            Model model,
            @RequestParam(name = "nameSortBy", required = false) String nameSortBy,
            @RequestParam(name = "ageSortBy", required = false) String ageSortBy,
            @RequestParam(name = "name", required = false) String name,
            @RequestParam(name = "age", required = false) String age
    ) {
        List<Person> persons = new ArrayList<>();
        persons.add(new Person("Alice", 15));
        persons.add(new Person("Bob", 10));
        persons.add(new Person("Eve", 5));
        List<Person> filteredPersons = new ArrayList<>();
        for (Person person : persons) {
            if (!isEmpty(name) && !person.getName().equals(name)) {
                continue;
            }
            if (!isEmpty(age) && person.getAge() != Integer.parseInt(age)) {
                continue;
            }
            filteredPersons.add(person);
        }
        Comparator<Person> c;
        c = Comparator.comparing(Person::getName, "desc".equals(nameSortBy) ? Comparator.reverseOrder() : Comparator.naturalOrder());
        c.thenComparing(Person::getAge, "desc".equals(ageSortBy) ? Comparator.reverseOrder() : Comparator.naturalOrder());
        filteredPersons.sort(c);
        model.addAttribute("persons", filteredPersons);
        return "index.html";
    }

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

    public class Person {
        private String name;
        private int age;
        public Person() {
        }
        public Person(String name, int age) {
            this.name = name;
            this.age = age;
        }
        public String getName() { return name; }
        public void setName(String name) { this.name = name; }
        public int getAge() { return age; }
        public void setAge(int age) { this.age = age; }
    }

    public static boolean isEmpty(String s) {
        return s == null || s.length() == 0;
    }
}