Improve wiki link handling (#1184)

* handle wiki links with dashes and index wiki page

* properly handle w vs wiki and links with wiki in it twice

* remove beginning and end of line tokens from wiki regex

* optimize wiki regex

app/src/main/java/ml/docilealligator/infinityforreddit/activities/LinkResolverActivity.java

@@ -50,7 +50,7 @@ public class LinkResolverActivity extends AppCompatActivity {
     private static final String IMGUR_ALBUM_PATTERN = "/(album|a)/\\w+/?";
     private static final String IMGUR_IMAGE_PATTERN = "/\\w+/?";
     private static final String RPAN_BROADCAST_PATTERN = "/rpan/r/[\\w-]+/\\w+/?\\w+/?";
-    private static final String WIKI_PATTERN = "/[rR]/[\\w-]+/(wiki|w)?(?:/\\w+)+";
+    private static final String WIKI_PATTERN = "/[rR]/[\\w-]+/(wiki|w)(?:/[\\w-]+)*";
     private static final String GOOGLE_AMP_PATTERN = "/amp/s/amp.reddit.com/.*";
     private static final String STREAMABLE_PATTERN = "/\\w+/?";
 
@@ -206,7 +206,17 @@ private void handleUri(Uri uri) {
                                     deepLinkError(uri);
                                 }
                             } else if (path.matches(WIKI_PATTERN)) {
-                                final String wikiPage = path.substring(path.lastIndexOf("/wiki/") + 6);
+                                String[] pathSegments = path.split("/");
+                                String wikiPage;
+                                if (pathSegments.length == 4) {
+                                    wikiPage = "index";
+                                } else {
+                                    int lengthThroughWiki = 0;
+                                    for (int i = 1; i <= 3; ++i) {
+                                        lengthThroughWiki += pathSegments[i].length() + 1;
+                                    }
+                                    wikiPage = path.substring(lengthThroughWiki);
+                                }
                                 Intent intent = new Intent(this, WikiActivity.class);
                                 intent.putExtra(WikiActivity.EXTRA_SUBREDDIT_NAME, segments.get(1));
                                 intent.putExtra(WikiActivity.EXTRA_WIKI_PATH, wikiPage);