Elton Minetto
101 lines
1.8 KiB
Go
101 lines
1.8 KiB
Go
package loan
|
|
|
|
import (
|
|
"github.com/eminetto/clean-architecture-go-v2/domain"
|
|
"github.com/eminetto/clean-architecture-go-v2/domain/entity"
|
|
"github.com/eminetto/clean-architecture-go-v2/domain/entity/book"
|
|
"github.com/eminetto/clean-architecture-go-v2/domain/entity/user"
|
|
)
|
|
|
|
type usecase struct {
|
|
uService user.Repository
|
|
bService book.Repository
|
|
}
|
|
|
|
//NewUseCase create new use case
|
|
func NewUseCase(u user.Repository, b book.Repository) *usecase {
|
|
return &usecase{
|
|
uService: u,
|
|
bService: b,
|
|
}
|
|
}
|
|
|
|
//Borrow borrow a book to an user
|
|
func (s *usecase) Borrow(u *user.User, b *book.Book) error {
|
|
u, err := s.uService.Get(u.ID)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
b, err = s.bService.Get(b.ID)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if b.Quantity <= 0 {
|
|
return domain.ErrNotEnoughBooks
|
|
}
|
|
for _, v := range u.Books {
|
|
if v == b.ID {
|
|
return domain.ErrBookAlreadyBorrowed
|
|
}
|
|
}
|
|
u.Books = append(u.Books, b.ID)
|
|
err = s.uService.Update(u)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
b.Quantity--
|
|
err = s.bService.Update(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
//Return return a book
|
|
func (s *usecase) Return(b *book.Book) error {
|
|
b, err := s.bService.Get(b.ID)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
all, err := s.uService.List()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
borrowed := false
|
|
var borrowedBy entity.ID
|
|
for _, u := range all {
|
|
for _, bookID := range u.Books {
|
|
if bookID == b.ID {
|
|
borrowed = true
|
|
borrowedBy = u.ID
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if !borrowed {
|
|
return domain.ErrBookNotBorrowed
|
|
}
|
|
u, err := s.uService.Get(borrowedBy)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for i, j := range u.Books {
|
|
if j == b.ID {
|
|
u.Books = append(u.Books[:i], u.Books[i+1:]...)
|
|
err = s.uService.Update(u)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
break
|
|
}
|
|
}
|
|
b.Quantity++
|
|
err = s.bService.Update(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|