replaceTags and clearUnusedTags are added (#219)

* clearUnusedTags and replaceTags are added

* added clearUnusedTags and replaceTags

* added clearUnusedTags and replaceTags

* removed whitespaces and indentations

* removed white spaces and indentations

actions/notes.md

@@ -284,6 +284,75 @@
     }
     ```
 
+*   **clearUnusedTags**
+
+    Clears all the unused tags in the notes for the current user.
+
+    *Sample request*:
+    ```json
+    {
+        "action": "clearUnusedTags",
+        "version": 6
+    }
+    ```
+
+    *Sample result*:
+    ```json
+    {
+        "result": null,
+        "error": null
+    }
+    ```
+
+*   **replaceTags**
+
+    Replace tags in notes by note ID.
+
+    *Sample request*:
+    ```json
+    {
+        "action": "replaceTags",
+        "version": 6,
+        "params": {
+            "notes": [1483959289817, 1483959291695],
+            "tag_to_replace": "european-languages",
+            "replace_with_tag": "french-languages"
+        }
+    }
+    ```
+
+    *Sample result*:
+    ```json
+    {
+        "result": null,
+        "error": null
+    }
+    ```
+
+*   **replaceTagsInAllNotes**
+
+    Replace tags in all the notes for the current user.
+
+    *Sample request*:
+    ```json
+    {
+        "action": "replaceTagsInAllCards",
+        "version": 6,
+        "params": {
+            "tag_to_replace": "european-languages",
+            "replace_with_tag": "french-languages"
+        }
+    }
+    ```
+
+    *Sample result*:
+    ```json
+    {
+        "result": null,
+        "error": null
+    }
+    ```
+
 *   **findNotes**
 
     Returns an array of note IDs for a given query. Same query syntax as `guiBrowse`.

plugin/__init__.py

@@ -615,6 +615,41 @@ class AnkiConnect:
     def getTags(self):
         return self.collection().tags.all()
 
+    @util.api()
+    def clearUnusedTags(self):
+        self.collection().tags.registerNotes()     
+    
+    @util.api()
+    def replaceTags(self, notes, tag_to_replace, replace_with_tag):
+        if self.collection() is not None:
+            self.window().progress.start()
+            for nid in notes:
+                note = self.collection().getNote(nid)
+                if note.hasTag(tag_to_replace):
+                    note.delTag(tag_to_replace)
+                    note.addtag(replace_with_tag)
+                    note.flush()
+            self.window().requireReset()
+            self.window().progress.finish()
+            self.window().reset()
+
+    @util.api()
+    def replaceTagsInAllNotes(self, tag_to_replace, replace_with_tag):
+        collection = self.collection()
+        if collection is not None:
+            nids = collection.db.list('select id from notes')
+            self.window().progress.start()
+            for nid in nids:
+                note = collection.getNote(nid)
+                if note.hasTag(tag_to_replace):
+                    note.delTag(tag_to_replace)
+                    note.addtag(replace_with_tag)
+                    note.flush()
+            self.window().requireReset()
+            self.window().progress.finish()
+            self.window().reset()
+        return False     
+    
     @util.api()
     def setEaseFactors(self, cards, easeFactors):
         couldSetEaseFactors = []