Add link service

link/service.go

@@ -0,0 +1,63 @@
+package link
+
+import (
+	. "cgnolink/err"
+)
+
+type Service interface {
+	Create(link *Link) error
+	GetById(id string) (*Link, error)
+	GetAll(limit int, offset int) (Links, error)
+	DeleteById(id string) error
+}
+
+type PgService struct {
+	rep PgRepository
+}
+
+func (s *PgService) Create(link *Link) error {
+	existingLink, err := s.rep.FindById(link.Id)
+	if err != nil {
+		return UnknownError{}
+	}
+
+	if existingLink != nil {
+		return AlreadyExistsError{Message: "Link with given ID already exists."}
+	}
+
+	if err = s.rep.Save(link); err != nil {
+		return UnknownError{}
+	}
+
+	return nil
+}
+
+func (s *PgService) GetById(id string) (*Link, error) {
+	link, err := s.rep.FindById(id)
+	if err != nil {
+		return nil, UnknownError{}
+	}
+
+	if link == nil {
+		return nil, NotFoundError{Message: "Link with given ID was not found."}
+	}
+
+	return link, nil
+}
+
+func (s *PgService) GetAll(limit int, offset int) (Links, error) {
+	links, err := s.rep.FindAll(limit, offset)
+	if err != nil {
+		return nil, UnknownError{}
+	}
+
+	return links, nil
+}
+
+func (s *PgService) DeleteById(id string) error {
+	if err := s.rep.DeleteById(id); err != nil {
+		return UnknownError{}
+	}
+
+	return nil
+}