add updateGeminiPage and refactor newGeminiPage to use updateGeminiPage.

fetch/fetch.go

@@ -66,9 +66,7 @@ func UpdateFeed(f *core.Feed) error {
 func UpdatePage(p *core.Page) error {
 	switch p.Link.Scheme {
 	case "gemini":
-		// return updateGeminiPage(p)
-		// TODO
-		fallthrough
+		return updateGeminiPage(p)
 	case "http", "https":
 		// return updateHTTPPage(p)
 		// TODO

fetch/gemini.go

@@ -60,6 +60,7 @@ func newGeminiFeed(remoteURL *url.URL, title string) (*core.Feed, error) {
 		var feed core.Feed
 		feed.Title = title // will be set later if given title is ""
 		feed.Link = remoteURL
+		feed.FeedLink = remoteURL
 		text, err := gemini.ParseText(resp.Body)
 		if err != nil {
 			return nil, err
@@ -110,24 +111,35 @@ func newGeminiFeed(remoteURL *url.URL, title string) (*core.Feed, error) {
 
 // newGeminiPage will create a new core.Page given a gemini url
 func newGeminiPage(remoteURL *url.URL, title string) (*core.Page, error) {
-	resp, err := fetchGemini(remoteURL)
+	var page core.Page
+	page.Title = title
+	page.Link = remoteURL
+
+	err := updateGeminiPage(&page)
 	if err != nil {
 		return nil, err
 	}
+	return &page, nil
+}
+
+// updateGeminiPage will check an existing core.Page for changes
+func updateGeminiPage(p *core.Page) error {
+	resp, err := fetchGemini(p.Link)
+	if err != nil {
+		return err
+	}
 	defer resp.Body.Close()
 
 	reader := io.LimitReader(resp.Body, 1073741824) // 1 GiB
 
-	var page core.Page
-	page.Title = title
-	page.Link = remoteURL
-	page.Updated = time.Now()
-
 	h := sha256.New()
 	if _, err := io.Copy(h, reader); err != nil {
-		return nil, err
+		return err
 	}
-	page.Hash = fmt.Sprintf("%x", h.Sum(nil))
-
-	return &page, nil
+	newHash := fmt.Sprintf("%x", h.Sum(nil))
+	if newHash != p.Hash {
+		p.Hash = newHash
+		p.Updated = time.Now()
+	}
+	return nil
 }