improve login() and login retry

tcc-exporter

@@ -12,7 +12,7 @@ import urllib.request
 from http.server import HTTPServer, BaseHTTPRequestHandler
 from urllib.error import HTTPError
 
-VERSION = '0.8.3'
+VERSION = '0.8.4'
 PREFIX = 'https://mytotalconnectcomfort.com/'
 devices = list()
 
@@ -54,6 +54,7 @@ class Client(object):
         if '/portal/Account/LogOff' in decoded:
           log('INFO', 'TCC portal login successful.')
           self._backoff = 0
+          return True
         else:
           log('WARNING', 'TCC portal login failed.')
           if (self._backoff < self._min_backoff):
@@ -63,10 +64,13 @@ class Client(object):
           else:
             self._backoff = self._backoff * 2
           log('INFO', 'Set login retry delay to {0} seconds.'.format(self._backoff))
+          return False
       except Exception as e:
         log('ERROR', '{0} {1}: {2!r}'.format(inspect.currentframe().f_code.co_name, type(e).__name__, e.args))
+        return False
     else:
       log('INFO', 'Login retry delayed another {0} seconds.'.format(int(self._last_login + self._backoff - utc_seconds)))
+      return False
 
   def _request(self, path, data={}, headers={}):
     if isinstance(data, str):
@@ -96,14 +100,15 @@ class Client(object):
   def _request_data(self, path, data={}, headers={}):
     data = self._request(path, data, headers)
     if isinstance(data, int) and (data == 401): # Login failure, lets try to login again.
-      log('INFO', 'Retrying Client.login()')
-      self.login()
-      data = self._request(path, data, headers)
+      if self.login():
+        data = self._request(path, data, headers)
     if isinstance(data, int):
       return data # Another failure, just return the code.
     reader = codecs.getreader(data.headers.get_content_charset())
     try:
-      return json.load(reader(data))
+      retval = json.load(reader(data))
+      self._backoff = 0 # We got decodable JSON, reset the backoff.
+      return retval
     except json.JSONDecodeError as e:
       log('INFO', 'TCC portal returned invalid data.')
       return 502