feed.Fetch parses and matches many fields

src/feeds/http.go

@@ -3,9 +3,14 @@ package feeds
 import (
 	"context"
 	"fmt"
-	"io"
+	"regexp"
+	"slices"
+	"sort"
+	"strings"
 	"time"
 
+	"github.com/jaytaylor/html2text"
+	"github.com/mmcdole/gofeed"
 	"github.com/robfig/cron/v3"
 )
 
@@ -31,5 +36,51 @@ func (feed Feed) ShouldExecute() (bool, error) {
 }
 
 func (feed Feed) Fetch(ctx context.Context) (Items, error) {
-	return nil, io.EOF
+	gfeed, err := gofeed.NewParser().ParseURLWithContext(feed.Version.URL, ctx)
+	if err != nil {
+		return nil, err
+	}
+	sort.Sort(gfeed)
+
+	matcher := regexp.MustCompile(feed.Version.Pattern)
+
+	result := make(Items, 0, len(gfeed.Items))
+	for _, gitem := range gfeed.Items {
+		if matches := slices.DeleteFunc(append([]string{
+			gitem.Title,
+			gitem.Description,
+			gitem.Content,
+			gitem.Link,
+			gitem.Author.Name,
+			gitem.Author.Email,
+		}, gitem.Links...), func(s string) bool {
+			return !matcher.MatchString(s)
+		}); len(matches) == 0 {
+			continue
+		}
+
+		preview, _ := html2text.FromString(gitem.Description)
+		body, _ := html2text.FromString(gitem.Content)
+		if body == "" {
+			body = preview
+			if len(preview) > 53 {
+				preview = preview[:50] + "..."
+			}
+		}
+
+		links := slices.DeleteFunc(append([]string{gitem.Link}, gitem.Links...), func(s string) bool {
+			return strings.TrimSpace(s) == ""
+		})
+		slices.Sort(links)
+		links = slices.Compact(links)
+
+		result = append(result, Item{
+			Title:   gitem.Title,
+			Links:   links,
+			Preview: preview,
+			Body:    body,
+		})
+	}
+
+	return result, nil
 }