Refactor JSON Feed parser to use an adapter

internal/reader/json/adapter.go

@@ -0,0 +1,173 @@
+// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package json // import "miniflux.app/v2/internal/reader/json"
+
+import (
+	"log/slog"
+	"sort"
+	"strings"
+	"time"
+
+	"miniflux.app/v2/internal/crypto"
+	"miniflux.app/v2/internal/model"
+	"miniflux.app/v2/internal/reader/date"
+	"miniflux.app/v2/internal/reader/sanitizer"
+	"miniflux.app/v2/internal/urllib"
+)
+
+type JSONAdapter struct {
+	jsonFeed *JSONFeed
+}
+
+func NewJSONAdapter(jsonFeed *JSONFeed) *JSONAdapter {
+	return &JSONAdapter{jsonFeed}
+}
+
+func (j *JSONAdapter) BuildFeed(feedURL string) *model.Feed {
+	feed := &model.Feed{
+		Title:   strings.TrimSpace(j.jsonFeed.Title),
+		FeedURL: j.jsonFeed.FeedURL,
+		SiteURL: j.jsonFeed.HomePageURL,
+	}
+
+	if feed.FeedURL == "" {
+		feed.FeedURL = feedURL
+	}
+
+	// Fallback to the feed URL if the site URL is empty.
+	if feed.SiteURL == "" {
+		feed.SiteURL = feed.FeedURL
+	}
+
+	if feedURL, err := urllib.AbsoluteURL(feedURL, j.jsonFeed.FeedURL); err == nil {
+		feed.FeedURL = feedURL
+	}
+
+	if siteURL, err := urllib.AbsoluteURL(feedURL, j.jsonFeed.HomePageURL); err == nil {
+		feed.SiteURL = siteURL
+	}
+
+	// Fallback to the feed URL if the title is empty.
+	if feed.Title == "" {
+		feed.Title = feed.SiteURL
+	}
+
+	// Populate the icon URL if present.
+	for _, iconURL := range []string{j.jsonFeed.FaviconURL, j.jsonFeed.IconURL} {
+		iconURL = strings.TrimSpace(iconURL)
+		if iconURL != "" {
+			if absoluteIconURL, err := urllib.AbsoluteURL(feed.SiteURL, iconURL); err == nil {
+				feed.IconURL = absoluteIconURL
+				break
+			}
+		}
+	}
+
+	for _, item := range j.jsonFeed.Items {
+		entry := model.NewEntry()
+		entry.Title = strings.TrimSpace(item.Title)
+		entry.URL = strings.TrimSpace(item.URL)
+
+		// Make sure the entry URL is absolute.
+		if entryURL, err := urllib.AbsoluteURL(feed.SiteURL, entry.URL); err == nil {
+			entry.URL = entryURL
+		}
+
+		// The entry title is optional, so we need to find a fallback.
+		if entry.Title == "" {
+			for _, value := range []string{item.Summary, item.ContentText, item.ContentHTML} {
+				if value != "" {
+					entry.Title = sanitizer.TruncateHTML(value, 100)
+				}
+			}
+		}
+
+		// Fallback to the entry URL if the title is empty.
+		if entry.Title == "" {
+			entry.Title = entry.URL
+		}
+
+		// Populate the entry content.
+		for _, value := range []string{item.ContentHTML, item.ContentText, item.Summary} {
+			value = strings.TrimSpace(value)
+			if value != "" {
+				entry.Content = value
+				break
+			}
+		}
+
+		// Populate the entry date.
+		entry.Date = time.Now()
+		for _, value := range []string{item.DatePublished, item.DateModified} {
+			value = strings.TrimSpace(value)
+			if value != "" {
+				if date, err := date.Parse(value); err != nil {
+					slog.Debug("Unable to parse date from JSON feed",
+						slog.String("date", value),
+						slog.String("url", entry.URL),
+						slog.Any("error", err),
+					)
+				} else {
+					entry.Date = date
+					break
+				}
+			}
+		}
+
+		// Populate the entry author.
+		itemAuthors := append(item.Authors, j.jsonFeed.Authors...)
+		itemAuthors = append(itemAuthors, item.Author, j.jsonFeed.Author)
+
+		authorNamesMap := make(map[string]bool)
+		for _, author := range itemAuthors {
+			authorName := strings.TrimSpace(author.Name)
+			if authorName != "" {
+				authorNamesMap[authorName] = true
+			}
+		}
+
+		var authors []string
+		for authorName := range authorNamesMap {
+			authors = append(authors, authorName)
+		}
+
+		sort.Strings(authors)
+		entry.Author = strings.Join(authors, ", ")
+
+		// Populate the entry enclosures.
+		for _, attachment := range item.Attachments {
+			attachmentURL := strings.TrimSpace(attachment.URL)
+			if attachmentURL != "" {
+				if absoluteAttachmentURL, err := urllib.AbsoluteURL(feed.SiteURL, attachmentURL); err == nil {
+					entry.Enclosures = append(entry.Enclosures, &model.Enclosure{
+						URL:      absoluteAttachmentURL,
+						MimeType: attachment.MimeType,
+						Size:     attachment.Size,
+					})
+				}
+			}
+		}
+
+		// Populate the entry tags.
+		for _, tag := range item.Tags {
+			tag = strings.TrimSpace(tag)
+			if tag != "" {
+				entry.Tags = append(entry.Tags, tag)
+			}
+		}
+
+		// Generate a hash for the entry.
+		for _, value := range []string{item.ID, item.URL, item.ContentText + item.ContentHTML + item.Summary} {
+			value = strings.TrimSpace(value)
+			if value != "" {
+				entry.Hash = crypto.Hash(value)
+				break
+			}
+		}
+
+		feed.Entries = append(feed.Entries, entry)
+	}
+
+	return feed
+}