Allow specifying sort order and tags through config

internal/feed/lobsters.go

@@ -2,6 +2,7 @@ package feed
 
 import (
 	"net/http"
+	"strings"
 	"time"
 )
 
@@ -54,7 +55,22 @@ func getLobstersPostsFromFeed(feedUrl string) (ForumPosts, error) {
 	return posts, nil
 }
 
-func FetchLobstersTopPosts(feedUrl string) (ForumPosts, error) {
+func FetchLobstersPosts(sortBy string, tags []string) (ForumPosts, error) {
+	var feedUrl string
+
+	if sortBy == "hot" {
+		sortBy = "hottest"
+	} else if sortBy == "new" {
+		sortBy = "newest"
+	}
+
+	if len(tags) == 0 {
+		feedUrl = "https://lobste.rs/" + sortBy + ".json"
+	} else {
+		tags := strings.Join(tags, ",")
+		feedUrl = "https://lobste.rs/t/" + tags + ".json"
+	}
+
 	posts, err := getLobstersPostsFromFeed(feedUrl)
 
 	if err != nil {