Refactor RDF parser to use an adapter

Avoid tight coupling between `model.Feed` and the original XML RDF feed.

internal/reader/rdf/rdf.go

@@ -5,130 +5,27 @@ package rdf // import "miniflux.app/v2/internal/reader/rdf"
 
 import (
 	"encoding/xml"
-	"html"
-	"log/slog"
-	"strings"
-	"time"
 
-	"miniflux.app/v2/internal/crypto"
-	"miniflux.app/v2/internal/model"
-	"miniflux.app/v2/internal/reader/date"
 	"miniflux.app/v2/internal/reader/dublincore"
-	"miniflux.app/v2/internal/reader/sanitizer"
-	"miniflux.app/v2/internal/urllib"
 )
 
-type rdfFeed struct {
-	XMLName xml.Name  `xml:"RDF"`
-	Title   string    `xml:"channel>title"`
-	Link    string    `xml:"channel>link"`
-	Items   []rdfItem `xml:"item"`
-	dublincore.DublinCoreFeedElement
+// RDF sepcs: https://web.resource.org/rss/1.0/spec
+type RDF struct {
+	XMLName xml.Name   `xml:"http://www.w3.org/1999/02/22-rdf-syntax-ns# RDF"`
+	Channel RDFChannel `xml:"channel"`
+	Items   []RDFItem  `xml:"item"`
 }
 
-func (r *rdfFeed) Transform(baseURL string) *model.Feed {
-	var err error
-	feed := new(model.Feed)
-	feed.Title = sanitizer.StripTags(r.Title)
-	feed.FeedURL = baseURL
-	feed.SiteURL, err = urllib.AbsoluteURL(baseURL, r.Link)
-	if err != nil {
-		feed.SiteURL = r.Link
-	}
-
-	for _, item := range r.Items {
-		entry := item.Transform()
-		if entry.Author == "" && r.DublinCoreCreator != "" {
-			entry.Author = r.GetSanitizedCreator()
-		}
-
-		if entry.URL == "" {
-			entry.URL = feed.SiteURL
-		} else {
-			entryURL, err := urllib.AbsoluteURL(feed.SiteURL, entry.URL)
-			if err == nil {
-				entry.URL = entryURL
-			}
-		}
-
-		feed.Entries = append(feed.Entries, entry)
-	}
-
-	return feed
+type RDFChannel struct {
+	Title       string `xml:"title"`
+	Link        string `xml:"link"`
+	Description string `xml:"description"`
+	dublincore.DublinCoreChannelElement
 }
 
-type rdfItem struct {
+type RDFItem struct {
 	Title       string `xml:"http://purl.org/rss/1.0/ title"`
 	Link        string `xml:"link"`
 	Description string `xml:"description"`
 	dublincore.DublinCoreItemElement
 }
-
-func (r *rdfItem) Transform() *model.Entry {
-	entry := model.NewEntry()
-	entry.Title = r.entryTitle()
-	entry.Author = r.entryAuthor()
-	entry.URL = r.entryURL()
-	entry.Content = r.entryContent()
-	entry.Hash = r.entryHash()
-	entry.Date = r.entryDate()
-
-	if entry.Title == "" {
-		entry.Title = entry.URL
-	}
-	return entry
-}
-
-func (r *rdfItem) entryTitle() string {
-	for _, title := range []string{r.Title, r.DublinCoreTitle} {
-		title = strings.TrimSpace(title)
-		if title != "" {
-			return html.UnescapeString(title)
-		}
-	}
-	return ""
-}
-
-func (r *rdfItem) entryContent() string {
-	switch {
-	case r.DublinCoreContent != "":
-		return r.DublinCoreContent
-	default:
-		return r.Description
-	}
-}
-
-func (r *rdfItem) entryAuthor() string {
-	return r.GetSanitizedCreator()
-}
-
-func (r *rdfItem) entryURL() string {
-	return strings.TrimSpace(r.Link)
-}
-
-func (r *rdfItem) entryDate() time.Time {
-	if r.DublinCoreDate != "" {
-		result, err := date.Parse(r.DublinCoreDate)
-		if err != nil {
-			slog.Debug("Unable to parse date from RDF feed",
-				slog.String("date", r.DublinCoreDate),
-				slog.String("link", r.Link),
-				slog.Any("error", err),
-			)
-			return time.Now()
-		}
-
-		return result
-	}
-
-	return time.Now()
-}
-
-func (r *rdfItem) entryHash() string {
-	value := r.Link
-	if value == "" {
-		value = r.Title + r.Description
-	}
-
-	return crypto.Hash(value)
-}