Initial commit

internal/feed/rss.go

@@ -0,0 +1,117 @@
+package feed
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"sort"
+	"time"
+
+	"github.com/mmcdole/gofeed"
+)
+
+type RSSFeedItem struct {
+	ChannelName string
+	ChannelURL  string
+	Title       string
+	Link        string
+	ImageURL    string
+	PublishedAt time.Time
+}
+
+type RSSFeedRequest struct {
+	Url   string `yaml:"url"`
+	Title string `yaml:"title"`
+}
+
+type RSSFeedItems []RSSFeedItem
+
+func (f RSSFeedItems) SortByNewest() RSSFeedItems {
+	sort.Slice(f, func(i, j int) bool {
+		return f[i].PublishedAt.After(f[j].PublishedAt)
+	})
+
+	return f
+}
+
+var feedParser = gofeed.NewParser()
+
+func getItemsFromRSSFeedTask(request RSSFeedRequest) ([]RSSFeedItem, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	defer cancel()
+
+	feed, err := feedParser.ParseURLWithContext(request.Url, ctx)
+
+	if err != nil {
+		return nil, err
+	}
+
+	items := make(RSSFeedItems, 0, len(feed.Items))
+
+	for i := range feed.Items {
+		item := feed.Items[i]
+
+		rssItem := RSSFeedItem{
+			ChannelURL: feed.Link,
+			Title:      item.Title,
+			Link:       item.Link,
+		}
+
+		if request.Title != "" {
+			rssItem.ChannelName = request.Title
+		} else {
+			rssItem.ChannelName = feed.Title
+		}
+
+		if item.Image != nil {
+			rssItem.ImageURL = item.Image.URL
+		} else if feed.Image != nil {
+			rssItem.ImageURL = feed.Image.URL
+		}
+
+		if item.PublishedParsed != nil {
+			rssItem.PublishedAt = *item.PublishedParsed
+		} else {
+			rssItem.PublishedAt = time.Now()
+		}
+
+		items = append(items, rssItem)
+	}
+
+	return items, nil
+}
+
+func GetItemsFromRSSFeeds(requests []RSSFeedRequest) (RSSFeedItems, error) {
+	job := newJob(getItemsFromRSSFeedTask, requests).withWorkers(10)
+	feeds, errs, err := workerPoolDo(job)
+
+	if err != nil {
+		return nil, fmt.Errorf("%w: %v", ErrNoContent, err)
+	}
+
+	failed := 0
+
+	entries := make(RSSFeedItems, 0, len(feeds)*10)
+
+	for i := range feeds {
+		if errs[i] != nil {
+			failed++
+			slog.Error("failed to get rss feed", "error", errs[i], "url", requests[i].Url)
+			continue
+		}
+
+		entries = append(entries, feeds[i]...)
+	}
+
+	if len(entries) == 0 {
+		return nil, ErrNoContent
+	}
+
+	entries.SortByNewest()
+
+	if failed > 0 {
+		return entries, fmt.Errorf("%w: missing %d RSS feeds", ErrPartialContent, failed)
+	}
+
+	return entries, nil
+}