Use the kiwix::Reader instead of kiwix::Searcher to search suggestion.

The expected behavior from a user pov, is that suggestions return titles
starting with the searchPattern if no fulltext index is available.

`kiwix::Searcher` works only on a xapian database.
So `kiwix::Searcher::suggestions` will return results only if a embedded
fulltext is available.

This is `kiwix::Reader::searchSuggestionsSmart` that first try to do a
search with `kiwix::Searcher` and they fallback to titles starting with
the searchPattern.

src/searcher/kiwix-search.cpp

@@ -98,6 +98,19 @@ int main(int argc, char** argv)
      * directory */
   }
 
+  string searchString(search);
+
+  if (suggestionFlag) {
+    if (!reader) {
+      cerr << "Unable to open zim '" << zimPath << "'." << endl;
+      exit(1);
+    }
+    reader->searchSuggestionsSmart(searchString, 10);
+    std::string title;
+    while (reader->getNextSuggestion(title)) {
+      cout << title << endl;
+    }
+  } else {
     if (reader) {
       searcher = new kiwix::Searcher();
       searcher->add_reader(reader, "");
@@ -112,10 +125,6 @@ int main(int argc, char** argv)
 
     /* Start the indexing */
     if (searcher != NULL) {
-    string searchString(search);
-    if (suggestionFlag) {
-        searcher->suggestions(searchString, verboseFlag);
-    } else  {
       searcher->search(searchString, 0, 10, verboseFlag);
     }
     kiwix::Result* p_result;
@@ -123,15 +132,10 @@ int main(int argc, char** argv)
       cout << p_result->get_title() << endl;
       delete p_result;
     }
+  }
 
   delete searcher;
   delete reader;
 
-    //      kiwix::XapianSearcher::terminate();
-  } else {
-    cerr << "Unable instanciate the Kiwix searcher." << endl;
-    exit(1);
-  }
-
   exit(0);
 }