package app import ( "bytes" "errors" "io" "net/http" "owl-blogs/app/owlhttp" "owl-blogs/app/repository" "owl-blogs/interactions" "strings" "time" "golang.org/x/net/html" ) type WebmentionService struct { InteractionRepository repository.InteractionRepository EntryRepository repository.EntryRepository Http owlhttp.HttpClient } type ParsedHEntry struct { Title string } func NewWebmentionService( interactionRepository repository.InteractionRepository, entryRepository repository.EntryRepository, http owlhttp.HttpClient, ) *WebmentionService { return &WebmentionService{ InteractionRepository: interactionRepository, EntryRepository: entryRepository, Http: http, } } func readResponseBody(resp *http.Response) (string, error) { defer resp.Body.Close() bodyBytes, err := io.ReadAll(resp.Body) if err != nil { return "", err } return string(bodyBytes), nil } func collectText(n *html.Node, buf *bytes.Buffer) { if n.Type == html.TextNode { buf.WriteString(n.Data) } for c := n.FirstChild; c != nil; c = c.NextSibling { collectText(c, buf) } } func (WebmentionService) ParseHEntry(resp *http.Response) (ParsedHEntry, error) { htmlStr, err := readResponseBody(resp) if err != nil { return ParsedHEntry{}, err } doc, err := html.Parse(strings.NewReader(htmlStr)) if err != nil { return ParsedHEntry{}, err } var interpretHFeed func(*html.Node, *ParsedHEntry, bool) (ParsedHEntry, error) interpretHFeed = func(n *html.Node, curr *ParsedHEntry, parent bool) (ParsedHEntry, error) { attrs := n.Attr for _, attr := range attrs { if attr.Key == "class" && strings.Contains(attr.Val, "p-name") { buf := &bytes.Buffer{} collectText(n, buf) curr.Title = buf.String() return *curr, nil } } for c := n.FirstChild; c != nil; c = c.NextSibling { interpretHFeed(c, curr, false) } return *curr, nil } var findHFeed func(*html.Node) (ParsedHEntry, error) findHFeed = func(n *html.Node) (ParsedHEntry, error) { attrs := n.Attr for _, attr := range attrs { if attr.Key == "class" && strings.Contains(attr.Val, "h-entry") { return interpretHFeed(n, &ParsedHEntry{}, true) } } for c := n.FirstChild; c != nil; c = c.NextSibling { entry, err := findHFeed(c) if err == nil { return entry, nil } } return ParsedHEntry{}, errors.New("no h-entry found") } return findHFeed(doc) } func (s *WebmentionService) GetExistingWebmention(entryId string, source string, target string) (*interactions.Webmention, error) { inters, err := s.InteractionRepository.FindAll(entryId) if err != nil { return nil, err } for _, interaction := range inters { if webm, ok := interaction.(*interactions.Webmention); ok { m := webm.MetaData().(interactions.WebmentionMetaData) if m.Source == source && m.Target == target { return webm, nil } } } return nil, nil } func (s *WebmentionService) ProcessWebmention(source string, target string) error { resp, err := s.Http.Get(source) if err != nil { return err } hEntry, err := s.ParseHEntry(resp) if err != nil { return err } entryId := UrlToEntryId(target) println(entryId) println(entryId) println(entryId) println(entryId) _, err = s.EntryRepository.FindById(entryId) if err != nil { return err } webmention, err := s.GetExistingWebmention(entryId, source, target) if err != nil { return err } if webmention != nil { data := interactions.WebmentionMetaData{ Source: source, Target: target, Title: hEntry.Title, } webmention.SetMetaData(data) webmention.SetEntryID(entryId) webmention.SetCreatedAt(time.Now()) err = s.InteractionRepository.Update(webmention) return err } else { webmention = &interactions.Webmention{} data := interactions.WebmentionMetaData{ Source: source, Target: target, Title: hEntry.Title, } webmention.SetMetaData(&data) webmention.SetEntryID(entryId) webmention.SetCreatedAt(time.Now()) err = s.InteractionRepository.Create(webmention) return err } }