import os
import logging

class Extension:
  ''' Dynamic object carrying for objects to hold extensions '''
  def __init__(self, parent, folder, load_func='setup', exclusions=[]):
    self.folder = folder
    self.parent = parent
    self.load_func = load_func
    self.loaded = set()
    self.available = list()
    self.exclusions = exclusions

  def find_files(self):
    for root, dirs, files in os.walk(os.path.join(os.path.dirname(__file__), self.folder)):
      for x in files:
        if not x.startswith('_') and x.endswith('.py') and x not in self.exclusions \
          and not x.split('.', -1)[0] in self.exclusions:
          yield x.split('.')[0]

      if not '__init__.py' in files:
        with open(os.path.join(root, '__init__.py'), 'w') as f:
          f.write('pass')
      break

  def reload_setup_hooks(self):
    loaded = [x.__name__ for x in self.loaded]
    avail = [x.__name__ for x in self.available]
    for f in self.find_files():
      needs_containment = False
      if f in loaded+avail:
        mod = [x for x in self.loaded if x.__name__ == f][0]
      else:
        needs_containment = True
        mod = __import__(self.folder + '.' + f).__dict__[f]

      if hasattr(mod, 'USE'):
        if mod.USE:
          if hasattr(mod, self.load_func):
            try:
              getattr(mod, self.load_func)(self.parent)
            except Exception as e:
              logging.exception(
                mod.__name__ + ' Has failed to load due to [' + e.__class__.__name__ + '] Being raised.')
          else:
            logging.warning(mod.__name__ + ' Has no setup function. Ignoring...')
      else:
        logging.warning(mod.__name__ + ' Has no USE flag, ignoring...')

      if needs_containment:
        self.loaded.add(mod)


  def load_ext(self):
    ''' gimme moar stuff
    status protocol:
    0 = cant use
    1 = is using
    2 = can use

    '''
    fs = list(self.find_files())

    for mod in fs:
      try:
        _mod = __import__(self.folder + '.' + mod).__dict__[mod]
      except Exception as e:
        logging.exception(mod + ' Has failed to load due to [' + e.__class__.__name__ + '] Being raised.')
        yield 0, mod, e

      if hasattr(_mod, 'USE'):
        if _mod.USE:
          if hasattr(_mod, self.load_func):
            getattr(_mod, self.load_func)(self.parent)
            self.loaded.add(_mod)
            yield _mod, 1
          else:
            logging.warning(mod + ' Has no setup function. Ignoring...')
            yield _mod, 0
        else:
          yield _mod, 2
      else:
        logging.warning(mod + ' Has no USE flag, ignoring...')
        self.available.append(_mod)
        yield _mod, 2