feat: move entity and usecase to root folder

usecase/book/service.go

@@ -0,0 +1,85 @@
+package book
+
+import (
+	"strings"
+	"time"
+
+	"github.com/eminetto/clean-architecture-go-v2/entity"
+)
+
+//Service book usecase
+type Service struct {
+	repo Repository
+}
+
+//NewService create new service
+func NewService(r Repository) *Service {
+	return &Service{
+		repo: r,
+	}
+}
+
+//CreateBook create a book
+func (s *Service) CreateBook(title string, author string, pages int, quantity int) (entity.ID, error) {
+	b, err := entity.NewBook(title, author, pages, quantity)
+	if err != nil {
+		return b.ID, err
+	}
+	return s.repo.Create(b)
+}
+
+//GetBook get a book
+func (s *Service) GetBook(id entity.ID) (*entity.Book, error) {
+	b, err := s.repo.Get(id)
+	if b == nil {
+		return nil, entity.ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return b, nil
+}
+
+//SearchBooks search books
+func (s *Service) SearchBooks(query string) ([]*entity.Book, error) {
+	books, err := s.repo.Search(strings.ToLower(query))
+	if err != nil {
+		return nil, err
+	}
+	if len(books) == 0 {
+		return nil, entity.ErrNotFound
+	}
+	return books, nil
+}
+
+//ListBooks list books
+func (s *Service) ListBooks() ([]*entity.Book, error) {
+	books, err := s.repo.List()
+	if err != nil {
+		return nil, err
+	}
+	if len(books) == 0 {
+		return nil, entity.ErrNotFound
+	}
+	return books, nil
+}
+
+//DeleteBook Delete a book
+func (s *Service) DeleteBook(id entity.ID) error {
+	_, err := s.GetBook(id)
+	if err != nil {
+		return err
+	}
+	return s.repo.Delete(id)
+}
+
+//UpdateBook Update a book
+func (s *Service) UpdateBook(e *entity.Book) error {
+	err := e.Validate()
+	if err != nil {
+		return err
+	}
+	e.UpdatedAt = time.Now()
+	return s.repo.Update(e)
+}