from alert_config import Alert_Config

class Alert_Config_List() :
   def __init__(self, alert_configs=None) :
      self.hash = {}
      if alert_configs :
         self.add(alert_configs)

   def __getitem__(self, k) :
      return self.hash[k]

   def __len__(self) :
      return len(self.hash)

   def add(self, alert_config) :
      if isinstance(alert_config, Alert_Config):
         self.hash[alert_config.id] = alert_config
      elif isinstance(alert_config, list) :
         for a in alert_config :
            self.add(a)
      elif isinstance(alert_config, Alert_Config_List) :
         for k in alert_config.hash :
            self.add(alert_config.hash[k])
      else :
         raise Exception("unexpected type added to Alert_Config_List")

   def compare(self, other) :
      if not other :
         other = Alert_Config_List()
      self_keys = self.hash.keys()
      other_keys = other.hash.keys()
      added = other_keys - self_keys
      removed = self_keys - other_keys
      intersection = [i for i in self_keys if i in other_keys]
      modified = [ i for i in intersection if self[i] != other[i] ]
      return set(added), set(removed), set(modified)