package services import ( "crypto/md5" "encoding/hex" "git.solsynth.dev/hydrogen/dealer/pkg/internal/database" "git.solsynth.dev/hydrogen/dealer/pkg/internal/models" "github.com/gocolly/colly" "github.com/rs/zerolog/log" "github.com/samber/lo" "github.com/spf13/viper" "net" "net/http" "time" ) func RetrieveLinkMetaFromCache(target string) (models.LinkMeta, error) { hash := md5.Sum([]byte(target)) entry := hex.EncodeToString(hash[:]) var meta models.LinkMeta if err := database.C.Where("entry = ?", entry).First(&meta).Error; err != nil { return meta, err } return meta, nil } func SaveLinkMetaToCache(target string, meta models.LinkMeta) error { hash := md5.Sum([]byte(target)) entry := hex.EncodeToString(hash[:]) meta.Entry = entry return database.C.Save(&meta).Error } func LinkExpand(target string) (*models.LinkMeta, error) { if cache, err := RetrieveLinkMetaFromCache(target); err == nil { log.Debug().Str("url", target).Msg("Expanding link... hit cache") return &cache, nil } c := colly.NewCollector( colly.UserAgent(viper.GetString("scraper.user-agent")), colly.MaxDepth(3), ) c.WithTransport(&http.Transport{ Proxy: http.ProxyFromEnvironment, DialContext: (&net.Dialer{ Timeout: 60 * time.Second, KeepAlive: 360 * time.Second, }).DialContext, MaxIdleConns: 100, IdleConnTimeout: 90 * time.Second, TLSHandshakeTimeout: 10 * time.Second, ExpectContinueTimeout: 1 * time.Second, }) meta := &models.LinkMeta{ URL: target, } c.OnHTML("title", func(e *colly.HTMLElement) { meta.Title = &e.Text }) c.OnHTML("meta[name]", func(e *colly.HTMLElement) { switch e.Attr("name") { case "description": meta.Description = lo.ToPtr(e.Attr("content")) } }) c.OnHTML("meta[property]", func(e *colly.HTMLElement) { switch e.Attr("property") { case "og:title": meta.Title = lo.ToPtr(e.Attr("content")) case "og:description": meta.Description = lo.ToPtr(e.Attr("content")) case "og:image": meta.Image = lo.ToPtr(e.Attr("content")) case "og:video": meta.Video = lo.ToPtr(e.Attr("content")) case "og:audio": meta.Audio = lo.ToPtr(e.Attr("content")) case "og:site_name": meta.SiteName = lo.ToPtr(e.Attr("content")) case "og:type": meta.Type = lo.ToPtr(e.Attr("content")) } }) c.OnHTML("link[rel]", func(e *colly.HTMLElement) { if e.Attr("rel") == "icon" { meta.Icon = e.Request.AbsoluteURL(e.Attr("href")) } }) c.OnRequest(func(r *colly.Request) { log.Debug().Str("url", target).Msg("Expanding link... requesting") }) c.RedirectHandler = func(req *http.Request, via []*http.Request) error { log.Debug().Str("url", req.URL.String()).Msg("Expanding link... redirecting") return nil } c.OnResponse(func(r *colly.Response) { log.Debug().Str("url", target).Msg("Expanding link... analyzing") }) c.OnError(func(r *colly.Response, err error) { log.Warn().Err(err).Str("url", target).Msg("Expanding link... failed") }) c.OnScraped(func(r *colly.Response) { _ = SaveLinkMetaToCache(target, *meta) log.Debug().Str("url", target).Msg("Expanding link... finished") }) return meta, c.Visit(target) }