package com.rbezzi.playground.junit5;

import com.google.common.base.CaseFormat;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.DisplayNameGeneration;
import org.junit.jupiter.api.DisplayNameGenerator;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import static org.junit.jupiter.api.Assertions.assertEquals;

@DisplayName("A list")
@DisplayNameGeneration(NestedJunit5Tests.CamelToSpaces.class)
public class NestedJunit5Tests {

    private List<Integer> l = new ArrayList<>();

    @Test
    void whenIsEmptyHasSizeZero() {
        assertEquals(0, l.size());
    }

    @Nested
    class WhenHasOneElement {

        @BeforeEach
        void addOneElement() {
            l.add(100);
        }

        @Test
        void hasSize1() {
            assertEquals(1, l.size());
        }

        @Test
        void canGetElement0() {
            assertEquals(100, l.get(0));
        }
    }

    @Nested
    class WhenHasTwoElements {

        @BeforeEach
        void addTwoElements() {
            l.add(10);
            l.add(20);
        }

        @Test
        void hasSize2() {
            assertEquals(2, l.size());
        }

        @Test
        void getElement0and1() {
            assertEquals(10, l.get(0));
            assertEquals(20, l.get(1));
        }

    }

    static class CamelToSpaces extends DisplayNameGenerator.Standard {

        @Override
        public String generateDisplayNameForClass(Class<?> testClass) {
            return toSpaces(super.generateDisplayNameForClass(testClass));
        }

        @Override
        public String generateDisplayNameForNestedClass(Class<?> nestedClass) {
            return toSpaces(super.generateDisplayNameForNestedClass(nestedClass));
        }

        @Override
        public String generateDisplayNameForMethod(Class<?> testClass, Method testMethod) {
            return toSpaces(super.generateDisplayNameForMethod(testClass, testMethod));
        }

        private String toSpaces(String s) {
            return CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_HYPHEN, s)
                    .replaceAll("-", " ")
                    .replaceAll("(\\D)(\\d)", "$1 $2")
                    .replaceFirst("\\(\\)$", "");
        }
    }

    @Test
    void one() {
        assertEquals("has size 1 and", new CamelToSpaces().toSpaces("hasSize1And()"));
    }

    @Test
    void two() {
        assertEquals("get element 0 and 1", new CamelToSpaces().toSpaces("getElement0And1()"));
    }
}