import os
import logging
import inspect
import numpy as np


class smbLog(object):
  interpolator = "%s ==> %s"
  def __init__(self, level = logging.DEBUG):
    logging.basicConfig(
                         level = level,
                         format = '%(asctime)s %(levelname)s %(message)s',
                         filename = os.path.join(os.sep, 'tmp', 'baker.lol'),
                       )
    self.log = logging.getLogger()
  def debug(self, message = None):
    msg = smbLog.interpolator % (inspect.stack()[1][3], message)
    self.log.debug(msg)

  def info(self, message = None):
    msg = smbLog.interpolator % (inspect.stack()[1][3], message)
    self.log.info(msg)

  def warn(self, message = None):
    msg = smbLog.interpolator % (inspect.stack()[1][3], message)
    self.log.warn(msg)

  def error(self, message = None):
    msg = smbLog.interpolator % (inspect.stack()[1][3], message)
    self.log.error(msg)


smblog = smbLog(logging.DEBUG)

class smberror(Exception):
  """
    this is a silly little exception subclass
  """
  def __init__(self, val):
    self.value = val
  def __str__(self):
    return repr(self.value)

def rms(errors):
  """
    root mean square calculation
  """
  r = 0.0
  for i in errors:
    r += np.power(i, 2)
  r = np.sqrt(r / len(errors))
  return r

def exact_func(X):
  """
    the exact function used from baker's article (for testing)
  """
  x = X[0]
  y = X[0]
  return np.power((np.sin(x * np.pi) * np.cos(y * np.pi)), 2)

def exact_func_3D(X):
  """
    the exact function (3D) used from baker's article (for testing)
  """
  x = X[0]
  y = X[1]
  z = X[2]
  return np.power((np.sin(x * np.pi / 2.0) * np.sin(y * np.pi / 2.0) * np.sin(z * np.pi / 2.0)), 2)

def improved_answer(answer, exact, verbose=False):
  if not answer['error']:
    return True
  smblog.debug('error: %s' % answer['error'])
  smblog.debug('qlin:  %s' % answer['qlin'])
  smblog.debug('final: %s' % answer['final'])
  smblog.debug('exact: %s' % exact)

  if np.abs(answer['final'] - exact) <= np.abs(answer['qlin'] - exact):
    smblog.debug(":) improved result")
    return True
  else:
    smblog.debug(":( damaged result")
    return False