Dealer/pkg/internal/services/link_expander.go
2024-08-19 19:05:47 +08:00

116 lines
3.1 KiB
Go

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)
}