implement atom/rss/json feeds over gopher.

TODO: write gophermap->gemtext mapper so the same gemini feed parser can
be used on both.

fetch/gopher.go

@@ -11,6 +11,7 @@ import (
 	"io"
 	"time"
 
+	"github.com/mmcdole/gofeed"
 	"github.com/prologic/go-gopher"
 
 	"golang.nytpu.com/comitium/core"
@@ -28,8 +29,28 @@ func fetchGopher(remote string) (*gopher.Response, error) {
 // gopherFeed will fetch and insert a new core.Feed into a core.FullData given a
 // gopher url (or update if it's preexisting)
 func gopherFeed(data *core.FullData, remote string, title string) error {
-	// TODO
-	return fmt.Errorf("Feeds served over gopher are currently unsupported.")
+	resp, err := fetchGopher(remote)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if len(resp.Dir.Items) != 0 {
+		// TODO
+		return fmt.Errorf("Gemini-style feeds served over gopher are currently unsupported.")
+	}
+
+	reader := io.LimitReader(resp.Body, 1073741824) // 1 GiB
+	gofeed, err := gofeed.NewParser().Parse(reader)
+	if err != nil {
+		return err
+	}
+	feed, err := core.GofeedConvert(gofeed, title)
+	if err != nil {
+		return err
+	}
+	data.InsertFeed(feed, remote)
+	return nil
 }
 
 // gopherPage will fetch and insert a new core.Page into a core.FullData given a