Implement fuzzy search and ranking

The regex based method to find key matches does not work very well for deeper
hierarchies and partial matching of the hierarchy levels. This approach uses the
SequenceMatcher from the difflib module to compute a score for an entry and rank
them accordingly.

This change also filters out all hidden file system entries to avoid traversing
and evaluating Git repositories which are commonly used to store pass storages.

gnome-pass-search-provider.py

@@ -27,8 +27,9 @@
 
 from os import getenv
 from os import walk
-from os.path import expanduser
+from os.path import expanduser, join as path_join
 import re
+import difflib
 import subprocess
 
 import dbus
@@ -81,22 +82,25 @@ class SearchPassService(dbus.service.Object):
         pass
 
     def get_result_set(self, terms):
-        names = []
-        for term in terms:
-            names += self.get_password_names(term)
-        return set(names)
+        name = ' '.join(terms)
+        matcher = difflib.SequenceMatcher(b=name, autojunk=False)
+        matches = []
 
-    def get_password_names(self, name):
-        names = []
         for root, dirs, files in walk(self.password_store):
             dir_path = root[len(self.password_store) + 1:]
-            for file in files:
-                file_path = '{0}/{1}'.format(dir_path, file)
-                if re.match(r'.*{0}.*\.gpg$'.format(name),
-                            file_path,
-                            re.IGNORECASE):
-                    names.append(file_path[:-4])
-        return names
+
+            if dir_path.startswith('.'):
+                continue
+
+            for filename in files:
+                path = path_join(dir_path, filename)
+                matcher.set_seq1(path[:-4])
+                score = matcher.ratio()
+
+                if score >= 0.5:
+                    matches.append((score, path[:-4]))
+
+        return [x[1] for x in sorted(matches, key=lambda x: x[0], reverse=True)]
 
     def send_password_to_gpaste(self, name):
         pass_cmd = subprocess.run(