/
link_manager.go
155 lines (126 loc) · 3.17 KB
/
link_manager.go
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package link_manager
import (
"errors"
om "github.com/adairxie/delinkcious/pkg/object_model"
)
type LinkManager struct {
linkStore LinkStore
socialGraphManager om.SocialGraphManager
eventSink om.LinkManagerEvents
maxLinksPerUser int64
}
func (m *LinkManager) GetLinks(request om.GetLinksRequest) (result om.GetLinksResult, err error) {
if request.Username == "" {
err = errors.New("User name can't be empty")
return
}
result, err = m.linkStore.GetLinks(request)
return
}
// Very wasteful way to count links
func (m *LinkManager) getLinkCount(username string) (linkCount int64, err error) {
req := om.GetLinksRequest{Username: username}
res, err := m.GetLinks(req)
if err != nil {
return
}
linkCount += int64(len(res.Links))
for res.NextPageToken != "" {
req = om.GetLinksRequest{Username: username, StartToken: res.NextPageToken}
res, err = m.GetLinks(req)
if err != nil {
return
}
linkCount += int64(len(res.Links))
}
return
}
func (m *LinkManager) AddLink(request om.AddLinkRequest) (err error) {
if request.Url == "" {
return errors.New("the URL can't be empty")
}
if request.Username == "" {
return errors.New("the user name can't be empty")
}
linkCount, err := m.getLinkCount(request.Username)
if err != nil {
return
}
if linkCount >= m.maxLinksPerUser {
return errors.New("the user has too many links")
}
link, err := m.linkStore.AddLink(request)
if err != nil {
return
}
if m.eventSink != nil {
followers, err := m.socialGraphManager.GetFollowers(request.Username)
if err != nil {
return err
}
for follower, _ := range followers {
m.eventSink.OnLinkAdded(follower, link)
}
}
return
}
func (m *LinkManager) UpdateLink(request om.UpdateLinkRequest) (err error) {
if request.Url == "" {
return errors.New("the URL can't be empty")
}
if request.Username == "" {
return errors.New("the user name can't be empty")
}
link, err := m.linkStore.UpdateLink(request)
if err != nil {
return
}
if m.eventSink != nil {
followers, err := m.socialGraphManager.GetFollowers(request.Username)
if err != nil {
return err
}
for follower, _ := range followers {
m.eventSink.OnLinkUpdated(follower, link)
}
}
return
}
func (m *LinkManager) DeleteLink(username string, url string) (err error) {
if url == "" {
return errors.New("the URL can't be empty")
}
if username == "" {
return errors.New("the user name can't be empty")
}
err = m.linkStore.DeleteLink(username, url)
if err != nil {
return
}
if m.eventSink != nil {
followers, err := m.socialGraphManager.GetFollowers(username)
if err != nil {
return err
}
for follower, _ := range followers {
m.eventSink.OnLinkDeleted(follower, url)
}
}
return
}
func NewLinkManager(linkStore LinkStore,
socialGraphManager om.SocialGraphManager,
eventSink om.LinkManagerEvents,
maxLinksPerUser int64) (om.LinkManager, error) {
if linkStore == nil {
return nil, errors.New("link store")
}
if socialGraphManager == nil {
return nil, errors.New("social graph manager can't be nil")
}
return &LinkManager{
linkStore: linkStore,
socialGraphManager: socialGraphManager,
eventSink: eventSink,
}, nil
}