from sound_lib.main import bass_call
import ctypes
from sound_lib.external import pybass
import string #for the alphabet!

class SoundEffect(object):

 def __init__(self, channel, type=None, priority=0):
  self.original_channel = channel
  if hasattr(channel, 'handle'):
   channel = channel.handle
  if type is None:
   type = self.effect_type
  self.effect_type = type
  self.priority = priority
  self.handle = bass_call(pybass.BASS_ChannelSetFX, channel, type, priority)
  
 def get_parameters(self):
  """Retrieves the parameters of an effect."""
  res = {}
  params = self.struct()
  bass_call(pybass.BASS_FXGetParameters, self.handle, ctypes.pointer(params))
  for f in params._fields_:
   res[f[0]] = getattr(params, f[0])
  return res

 def set_parameters(self, parameters):
  params = self.struct()
  for p, v in parameters.items():
   setattr(params, p, v)
  bass_call(pybass.BASS_FXSetParameters, self.handle, ctypes.pointer(params))

 def __dir__(self):
  res = dir(self.__class__)
  return res + self._get_pythonic_effect_fields()

 def _get_effect_fields(self):
  return [i[0] for i in self.struct._fields_]

 def _get_pythonic_effect_fields(self):
  return [self._bass_to_python(i) for i in self._get_effect_fields() if not i.startswith('_') ]

 def _bass_to_python(self, func):
  for c in string.ascii_lowercase:
   func = func.replace(c.upper(), '_%s' % c)
  if func.startswith('_'):
   func = func[1:]
  return func[2:]
 
 def _python_to_bass(self, func):
  for c in string.ascii_lowercase:
   func = func.replace('_%s' % c, c.upper())
  func = '%s%s' % (func[0].upper(), func[1:])
  for f in self._get_effect_fields():
   if f.endswith(func):
    func = f
  return func
 
 def __getattr__(self, attr):
  return self.get_parameters()[self._python_to_bass(attr)]

 def __setattr__(self, attr, val):
  if attr not in self._get_pythonic_effect_fields():
   return super(SoundEffect, self).__setattr__(attr, val)
  params = self.get_parameters()
  key = self._python_to_bass(attr)
  if key not in params:
   raise AttributeError('Unable to set attribute, suspect issue with base name-munging code')
  params[key] = val
  self.set_parameters(params)