TodoService.java

package pro.hexa.study.backend.todo.service;

import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.Stream;
import pro.hexa.study.backend.todo.domain.ChildTodo;
import pro.hexa.study.backend.todo.domain.ParentTodo;
import pro.hexa.study.backend.todo.domain.Todo;
import pro.hexa.study.backend.todo.dto.SaveTodoRequest;
import pro.hexa.study.backend.todo.dto.TodoInquiryDto;
import pro.hexa.study.backend.todo.dto.TodoResponse;
import pro.hexa.study.backend.todo.dto.TodoUpdateDto;

/*
 * todoList를 위한 변환 로직
 */
public class TodoService {

    public static Long ID_COUNT;
    private List<Todo> todoEntities; // 저장되어있는 todo객체 전체

    /*
     * don't touch this function.
     */
    public TodoService() {
        ID_COUNT = 0L;
        this.todoEntities = Collections.emptyList();
    }

    /*
     * don't touch this function.
     */
    public void saveTodoEntities(List<Todo> todoEntities) {
        this.todoEntities = todoEntities;
    }

    /*
     * todoList를 todoResponse로 변환
     */
    public TodoResponse getTodoResponse() {
        //
        List<TodoInquiryDto> todoList = this.todoEntities.stream()
            .filter(ParentTodo.class::isInstance)
            .map(ParentTodo.class::cast)
            .map(this::createTodoInquiryDtoFromParentTodo)
            .collect(Collectors.toList());

        return new TodoResponse(todoList);
    }

    private TodoInquiryDto createTodoInquiryDtoFromParentTodo(ParentTodo parentTodo) {
        List<Long> id = Stream.concat(
            Stream.of(parentTodo.getId()),
            parentTodo.getDetails().stream()
                .map(Todo::getId)
        ).collect(Collectors.toList());
        String title = parentTodo.getTitle();
        String content = parentTodo.getContent();
        List<String> subTitles = parentTodo.getDetails().stream()
            .map(Todo::getTitle)
            .collect(Collectors.toList());
        List<String> detailContents = parentTodo.getDetails().stream()
            .map(Todo::getContent)
            .collect(Collectors.toList());
        short remainingTime = parentTodo.getTimeToTakeInMinutes();
        LocalDateTime startAt = parentTodo.getStartAt();
        boolean completeYn = parentTodo.getCompleteYn();
        return new TodoInquiryDto(id, title, content, subTitles, detailContents, remainingTime, startAt, completeYn);
    }

    /*
     * todoList 수정 요청 받아서 처리한 뒤 저장
     */
    public void saveTodo(SaveTodoRequest request) {
        // done
        for (Long todoDeleteId : request.getTodoDeleteIds()) {
            IntStream.range(0, todoEntities.size()).forEach(i -> {
                if (Objects.equals(todoEntities.get(i).getId(), todoDeleteId)) {
                    todoEntities.remove(i);
                    return;
                }
            });
        }
        for (TodoUpdateDto todoUpdateDto : request.getTodoUpdateList()) {
            boolean isTodoInTheList = this.todoEntities.stream()
                .anyMatch(todo -> Objects.equals(todo.getId(), todoUpdateDto.getId()));
            if (isTodoInTheList) {
                int index = IntStream.range(0, todoEntities.size())
                    .filter(i -> Objects.equals(todoEntities.get(i).getId(), todoUpdateDto.getId()))
                    .findFirst()
                    .orElse(-1);
                ((ParentTodo) todoEntities.get(index)).updateTodo(todoUpdateDto.getTitle(),
                    todoUpdateDto.getDetail(),
                    (short) ChronoUnit.MINUTES.between(todoUpdateDto.getEndAt(), todoUpdateDto.getStartAt()),
                    todoUpdateDto.getStartAt(),
                    todoUpdateDto.getCompleteYn());
            } else if (todoUpdateDto.getId() == null) {
                ParentTodo newParentTodo = new ParentTodo(todoUpdateDto.getTitle(),
                    todoUpdateDto.getDetail(),
                    (short) ChronoUnit.MINUTES.between(todoUpdateDto.getEndAt(), todoUpdateDto.getStartAt()),
                    todoUpdateDto.getStartAt(),
                    todoUpdateDto.getCompleteYn());
                this.todoEntities.add(newParentTodo);
            } else {
                throw new RuntimeException("존재하지 않는 Todo Id");
            }
        }
    }
}