quota: Split up 'quota list' command

This is really three separate commands rolled into one. Split the logic
up more to simplify it somewhat.

Change-Id: Ief3c3c413f791dda076f90e5ec76a033d3a9e12b
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

openstackclient/common/quota.py

@@ -241,14 +241,10 @@ class ListQuota(command.Lister):
         )
         return parser
 
-    def take_action(self, parsed_args):
+    def _list_quota_compute(self, parsed_args, project_ids):
-        result = []
-        project_ids = [
-            p.id for p in self.app.client_manager.identity.projects.list()
-        ]
-
-        if parsed_args.compute:
         compute_client = self.app.client_manager.compute
+        result = []
+
         for p in project_ids:
             try:
                 data = compute_client.quotas.get(p)
@@ -309,8 +305,10 @@ class ListQuota(command.Lister):
             (utils.get_dict_properties(s, columns) for s in result),
         )
 
-        if parsed_args.volume:
+    def _list_quota_volume(self, parsed_args, project_ids):
         volume_client = self.app.client_manager.volume
+        result = []
+
         for p in project_ids:
             try:
                 data = volume_client.quotas.get(p)
@@ -360,8 +358,10 @@ class ListQuota(command.Lister):
             (utils.get_dict_properties(s, columns) for s in result),
         )
 
-        if parsed_args.network:
+    def _list_quota_network(self, parsed_args, project_ids):
         client = self.app.client_manager.network
+        result = []
+
         for p in project_ids:
             try:
                 data = client.get_quota(p)
@@ -417,6 +417,18 @@ class ListQuota(command.Lister):
             (utils.get_dict_properties(s, columns) for s in result),
         )
 
+    def take_action(self, parsed_args):
+        project_ids = [
+            p.id for p in self.app.client_manager.identity.projects.list()
+        ]
+        if parsed_args.compute:
+            return self._list_quota_compute(parsed_args, project_ids)
+        elif parsed_args.volume:
+            return self._list_quota_volume(parsed_args, project_ids)
+        elif parsed_args.network:
+            return self._list_quota_network(parsed_args, project_ids)
+
+        # will never get here
         return ((), ())