miniflux-v2/internal/reader/subscription/finder.go
jvoisin 45d486b919 When detecting the format, detect its version as well
There is no need to detect the format and then the version when both can be
done at the same time.

Add a benchmark as well, on large and small atom and rss files.
2024-03-12 18:56:56 -07:00

325 lines
11 KiB
Go

// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
// SPDX-License-Identifier: Apache-2.0
package subscription // import "miniflux.app/v2/internal/reader/subscription"
import (
"bytes"
"fmt"
"io"
"log/slog"
"regexp"
"miniflux.app/v2/internal/config"
"miniflux.app/v2/internal/integration/rssbridge"
"miniflux.app/v2/internal/locale"
"miniflux.app/v2/internal/model"
"miniflux.app/v2/internal/reader/encoding"
"miniflux.app/v2/internal/reader/fetcher"
"miniflux.app/v2/internal/reader/parser"
"miniflux.app/v2/internal/urllib"
"github.com/PuerkitoBio/goquery"
)
var (
youtubeChannelRegex = regexp.MustCompile(`youtube\.com/channel/(.*)$`)
youtubeVideoRegex = regexp.MustCompile(`youtube\.com/watch\?v=(.*)$`)
)
type SubscriptionFinder struct {
requestBuilder *fetcher.RequestBuilder
feedDownloaded bool
feedResponseInfo *model.FeedCreationRequestFromSubscriptionDiscovery
}
func NewSubscriptionFinder(requestBuilder *fetcher.RequestBuilder) *SubscriptionFinder {
return &SubscriptionFinder{
requestBuilder: requestBuilder,
}
}
func (f *SubscriptionFinder) IsFeedAlreadyDownloaded() bool {
return f.feedDownloaded
}
func (f *SubscriptionFinder) FeedResponseInfo() *model.FeedCreationRequestFromSubscriptionDiscovery {
return f.feedResponseInfo
}
func (f *SubscriptionFinder) FindSubscriptions(websiteURL, rssBridgeURL string) (Subscriptions, *locale.LocalizedErrorWrapper) {
responseHandler := fetcher.NewResponseHandler(f.requestBuilder.ExecuteRequest(websiteURL))
defer responseHandler.Close()
if localizedError := responseHandler.LocalizedError(); localizedError != nil {
slog.Warn("Unable to find subscriptions", slog.String("website_url", websiteURL), slog.Any("error", localizedError.Error()))
return nil, localizedError
}
responseBody, localizedError := responseHandler.ReadBody(config.Opts.HTTPClientMaxBodySize())
if localizedError != nil {
slog.Warn("Unable to find subscriptions", slog.String("website_url", websiteURL), slog.Any("error", localizedError.Error()))
return nil, localizedError
}
f.feedResponseInfo = &model.FeedCreationRequestFromSubscriptionDiscovery{
Content: bytes.NewReader(responseBody),
ETag: responseHandler.ETag(),
LastModified: responseHandler.LastModified(),
}
// Step 1) Check if the website URL is a feed.
if feedFormat, _ := parser.DetectFeedFormat(f.feedResponseInfo.Content); feedFormat != parser.FormatUnknown {
f.feedDownloaded = true
return Subscriptions{NewSubscription(responseHandler.EffectiveURL(), responseHandler.EffectiveURL(), feedFormat)}, nil
}
// Step 2) Check if the website URL is a YouTube channel.
slog.Debug("Try to detect feeds from YouTube channel page", slog.String("website_url", websiteURL))
subscriptions, localizedError := f.FindSubscriptionsFromYouTubeChannelPage(websiteURL)
if localizedError != nil {
return nil, localizedError
}
if len(subscriptions) > 0 {
slog.Debug("Subscriptions found from YouTube channel page", slog.String("website_url", websiteURL), slog.Any("subscriptions", subscriptions))
return subscriptions, nil
}
// Step 3) Check if the website URL is a YouTube video.
slog.Debug("Try to detect feeds from YouTube video page", slog.String("website_url", websiteURL))
subscriptions, localizedError = f.FindSubscriptionsFromYouTubeVideoPage(websiteURL)
if localizedError != nil {
return nil, localizedError
}
if len(subscriptions) > 0 {
slog.Debug("Subscriptions found from YouTube video page", slog.String("website_url", websiteURL), slog.Any("subscriptions", subscriptions))
return subscriptions, nil
}
// Step 4) Parse web page to find feeds from HTML meta tags.
slog.Debug("Try to detect feeds from HTML meta tags",
slog.String("website_url", websiteURL),
slog.String("content_type", responseHandler.ContentType()),
)
subscriptions, localizedError = f.FindSubscriptionsFromWebPage(websiteURL, responseHandler.ContentType(), bytes.NewReader(responseBody))
if localizedError != nil {
return nil, localizedError
}
if len(subscriptions) > 0 {
slog.Debug("Subscriptions found from web page", slog.String("website_url", websiteURL), slog.Any("subscriptions", subscriptions))
return subscriptions, nil
}
// Step 5) Check if the website URL can use RSS-Bridge.
if rssBridgeURL != "" {
slog.Debug("Try to detect feeds with RSS-Bridge", slog.String("website_url", websiteURL))
subscriptions, localizedError := f.FindSubscriptionsFromRSSBridge(websiteURL, rssBridgeURL)
if localizedError != nil {
return nil, localizedError
}
if len(subscriptions) > 0 {
slog.Debug("Subscriptions found from RSS-Bridge", slog.String("website_url", websiteURL), slog.Any("subscriptions", subscriptions))
return subscriptions, nil
}
}
// Step 6) Check if the website has a known feed URL.
slog.Debug("Try to detect feeds from well-known URLs", slog.String("website_url", websiteURL))
subscriptions, localizedError = f.FindSubscriptionsFromWellKnownURLs(websiteURL)
if localizedError != nil {
return nil, localizedError
}
if len(subscriptions) > 0 {
slog.Debug("Subscriptions found with well-known URLs", slog.String("website_url", websiteURL), slog.Any("subscriptions", subscriptions))
return subscriptions, nil
}
return nil, nil
}
func (f *SubscriptionFinder) FindSubscriptionsFromWebPage(websiteURL, contentType string, body io.Reader) (Subscriptions, *locale.LocalizedErrorWrapper) {
queries := map[string]string{
"link[type='application/rss+xml']": parser.FormatRSS,
"link[type='application/atom+xml']": parser.FormatAtom,
"link[type='application/json']": parser.FormatJSON,
"link[type='application/feed+json']": parser.FormatJSON,
}
htmlDocumentReader, err := encoding.CharsetReaderFromContentType(contentType, body)
if err != nil {
return nil, locale.NewLocalizedErrorWrapper(err, "error.unable_to_parse_html_document", err)
}
doc, err := goquery.NewDocumentFromReader(htmlDocumentReader)
if err != nil {
return nil, locale.NewLocalizedErrorWrapper(err, "error.unable_to_parse_html_document", err)
}
var subscriptions Subscriptions
subscriptionURLs := make(map[string]bool)
for query, kind := range queries {
doc.Find(query).Each(func(i int, s *goquery.Selection) {
subscription := new(Subscription)
subscription.Type = kind
if title, exists := s.Attr("title"); exists {
subscription.Title = title
}
if feedURL, exists := s.Attr("href"); exists {
if feedURL != "" {
subscription.URL, err = urllib.AbsoluteURL(websiteURL, feedURL)
if err != nil {
return
}
}
}
if subscription.Title == "" {
subscription.Title = subscription.URL
}
if subscription.URL != "" && !subscriptionURLs[subscription.URL] {
subscriptionURLs[subscription.URL] = true
subscriptions = append(subscriptions, subscription)
}
})
}
return subscriptions, nil
}
func (f *SubscriptionFinder) FindSubscriptionsFromWellKnownURLs(websiteURL string) (Subscriptions, *locale.LocalizedErrorWrapper) {
knownURLs := map[string]string{
"atom.xml": parser.FormatAtom,
"feed.xml": parser.FormatAtom,
"feed/": parser.FormatAtom,
"rss.xml": parser.FormatRSS,
"rss/": parser.FormatRSS,
"index.rss": parser.FormatRSS,
"index.xml": parser.FormatRSS,
"feed.atom": parser.FormatAtom,
}
websiteURLRoot := urllib.RootURL(websiteURL)
baseURLs := []string{
// Look for knownURLs in the root.
websiteURLRoot,
}
// Look for knownURLs in current subdirectory, such as 'example.com/blog/'.
websiteURL, _ = urllib.AbsoluteURL(websiteURL, "./")
if websiteURL != websiteURLRoot {
baseURLs = append(baseURLs, websiteURL)
}
var subscriptions Subscriptions
for _, baseURL := range baseURLs {
for knownURL, kind := range knownURLs {
fullURL, err := urllib.AbsoluteURL(baseURL, knownURL)
if err != nil {
continue
}
// Some websites redirects unknown URLs to the home page.
// As result, the list of known URLs is returned to the subscription list.
// We don't want the user to choose between invalid feed URLs.
f.requestBuilder.WithoutRedirects()
responseHandler := fetcher.NewResponseHandler(f.requestBuilder.ExecuteRequest(fullURL))
localizedError := responseHandler.LocalizedError()
responseHandler.Close()
if localizedError != nil {
slog.Debug("Unable to subscribe", slog.String("fullURL", fullURL), slog.Any("error", localizedError.Error()))
continue
}
subscriptions = append(subscriptions, &Subscription{
Type: kind,
Title: fullURL,
URL: fullURL,
})
}
}
return subscriptions, nil
}
func (f *SubscriptionFinder) FindSubscriptionsFromRSSBridge(websiteURL, rssBridgeURL string) (Subscriptions, *locale.LocalizedErrorWrapper) {
slog.Debug("Trying to detect feeds using RSS-Bridge",
slog.String("website_url", websiteURL),
slog.String("rssbridge_url", rssBridgeURL),
)
bridges, err := rssbridge.DetectBridges(rssBridgeURL, websiteURL)
if err != nil {
return nil, locale.NewLocalizedErrorWrapper(err, "error.unable_to_detect_rssbridge", err)
}
slog.Debug("RSS-Bridge results",
slog.String("website_url", websiteURL),
slog.String("rssbridge_url", rssBridgeURL),
slog.Int("nb_bridges", len(bridges)),
)
if len(bridges) == 0 {
return nil, nil
}
subscriptions := make(Subscriptions, 0, len(bridges))
for _, bridge := range bridges {
subscriptions = append(subscriptions, &Subscription{
Title: bridge.BridgeMeta.Name,
URL: bridge.URL,
Type: parser.FormatAtom,
})
}
return subscriptions, nil
}
func (f *SubscriptionFinder) FindSubscriptionsFromYouTubeChannelPage(websiteURL string) (Subscriptions, *locale.LocalizedErrorWrapper) {
matches := youtubeChannelRegex.FindStringSubmatch(websiteURL)
if len(matches) == 2 {
feedURL := fmt.Sprintf(`https://www.youtube.com/feeds/videos.xml?channel_id=%s`, matches[1])
return Subscriptions{NewSubscription(websiteURL, feedURL, parser.FormatAtom)}, nil
}
slog.Debug("This website is not a YouTube channel page, the regex doesn't match", slog.String("website_url", websiteURL))
return nil, nil
}
func (f *SubscriptionFinder) FindSubscriptionsFromYouTubeVideoPage(websiteURL string) (Subscriptions, *locale.LocalizedErrorWrapper) {
if !youtubeVideoRegex.MatchString(websiteURL) {
slog.Debug("This website is not a YouTube video page, the regex doesn't match", slog.String("website_url", websiteURL))
return nil, nil
}
responseHandler := fetcher.NewResponseHandler(f.requestBuilder.ExecuteRequest(websiteURL))
defer responseHandler.Close()
if localizedError := responseHandler.LocalizedError(); localizedError != nil {
return nil, localizedError
}
doc, docErr := goquery.NewDocumentFromReader(responseHandler.Body(config.Opts.HTTPClientMaxBodySize()))
if docErr != nil {
return nil, locale.NewLocalizedErrorWrapper(docErr, "error.unable_to_parse_html_document", docErr)
}
if channelID, exists := doc.Find(`meta[itemprop="channelId"]`).First().Attr("content"); exists {
feedURL := fmt.Sprintf(`https://www.youtube.com/feeds/videos.xml?channel_id=%s`, channelID)
return Subscriptions{NewSubscription(websiteURL, feedURL, parser.FormatAtom)}, nil
}
return nil, nil
}