import sys
import time
import os
import subprocess
import shlex
from fractions import Fraction
from functools import reduce
from optparse import Option
from queue import Queue
from threading import Thread

import numpy as np

class bcolors:
    """
    ASCII Colors (Blender code).

    https://svn.blender.org/svnroot/bf-blender/trunk/blender/build_files/scons/tools/bcolors.py
    http://stackoverflow.com/questions/287871/print-in-terminal-with-colors-using-python
    """

    HEADER    = '\033[95m'
    OKBLUE    = '\033[94m'
    OKGREEN   = '\033[92m'
    WARNING   = '\033[93m'
    FAIL      = '\033[91m'
    ENDC      = '\033[0m'
    BOLD      = '\033[1m'
    DIM       = '\033[2m'
    UNDERLINE = '\033[4m'
    CROSSOUT  = '\033[9m'

    def disable(self):
        self.HEADER = ''
        self.OKBLUE = ''
        self.OKGREEN = ''
        self.WARNING = ''
        self.FAIL = ''
        self.ENDC = ''
        self.BOLD = ''
        self.UNDERLINE = ''
        self.CROSSOUT = ''


# -----------------------------
def srepr(arg,glue = '\n'):
  """Joins arguments as individual lines."""
  if (not hasattr(arg, "strip") and
          (hasattr(arg, "__getitem__") or
           hasattr(arg, "__iter__"))):
     return glue.join(str(x) for x in arg)
  return arg if isinstance(arg,str) else repr(arg)

# -----------------------------
def croak(what, newline = True):
  """Writes formated to stderr."""
  if what is not None:
    sys.stderr.write(srepr(what,glue = '\n') + ('\n' if newline else ''))
  sys.stderr.flush()

# -----------------------------
def report(who = None,
           what = None):
  """Reports script and file name."""
  croak( (emph(who)+': ' if who is not None else '') + (what if what is not None else '') + '\n' )


# -----------------------------
def emph(what):
  """Formats string with emphasis."""
  return bcolors.BOLD+srepr(what)+bcolors.ENDC

# -----------------------------
def deemph(what):
  """Formats string with deemphasis."""
  return bcolors.DIM+srepr(what)+bcolors.ENDC

# -----------------------------
def delete(what):
  """Formats string as deleted."""
  return bcolors.DIM+srepr(what)+bcolors.ENDC

# -----------------------------
def strikeout(what):
  """Formats string as strikeout."""
  return bcolors.CROSSOUT+srepr(what)+bcolors.ENDC

# -----------------------------
def execute(cmd,
            streamIn = None,
            wd = './',
            env = None):
  """Executes a command in given directory and returns stdout and stderr for optional stdin."""
  initialPath = os.getcwd()
  os.chdir(wd)
  myEnv = os.environ if env is None else env
  process = subprocess.Popen(shlex.split(cmd),
                             stdout = subprocess.PIPE,
                             stderr = subprocess.PIPE,
                             stdin  = subprocess.PIPE,
                             env = myEnv)
  out,error = [i for i in (process.communicate() if streamIn is None
                                                 else process.communicate(streamIn.read().encode('utf-8')))]
  out   = out.decode('utf-8').replace('\x08','')
  error = error.decode('utf-8').replace('\x08','')
  os.chdir(initialPath)
  if process.returncode != 0: raise RuntimeError('{} failed with returncode {}'.format(cmd,process.returncode))
  return out,error

# -----------------------------
class extendableOption(Option):
  """
  Used for definition of new option parser action 'extend', which enables to take multiple option arguments.

  Adopted from online tutorial http://docs.python.org/library/optparse.html
  """

  ACTIONS = Option.ACTIONS + ("extend",)
  STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
  TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
  ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)

  def take_action(self, action, dest, opt, value, values, parser):
    if action == "extend":
      lvalue = value.split(",")
      values.ensure_value(dest, []).extend(lvalue)
    else:
      Option.take_action(self, action, dest, opt, value, values, parser)

# Print iterations progress
# from https://gist.github.com/aubricus/f91fb55dc6ba5557fbab06119420dd6a
def progressBar(iteration, total, prefix='', bar_length=50):
  """
  Call in a loop to create terminal progress bar.

  @params:
      iteration   - Required  : current iteration (Int)
      total       - Required  : total iterations (Int)
      prefix      - Optional  : prefix string (Str)
      bar_length  - Optional  : character length of bar (Int)
  """
  fraction = iteration / float(total)
  if not hasattr(progressBar, "last_fraction"):                                                     # first call to function
    progressBar.start_time    = time.time()
    progressBar.last_fraction = -1.0
    remaining_time = '   n/a'
  else:
    if fraction <= progressBar.last_fraction or iteration == 0:                                     # reset: called within a new loop
      progressBar.start_time    = time.time()
      progressBar.last_fraction = -1.0
      remaining_time = '   n/a'
    else:
      progressBar.last_fraction = fraction
      remainder = (total - iteration) * (time.time()-progressBar.start_time)/iteration
      remaining_time = '{: 3d}:'.format(int( remainder//3600)) + \
                       '{:02d}:'.format(int((remainder//60)%60)) + \
                       '{:02d}' .format(int( remainder     %60))

  filled_length = int(round(bar_length * fraction))
  bar = '█' * filled_length + '░' * (bar_length - filled_length)

  sys.stderr.write('\r{} {} {}'.format(prefix, bar, remaining_time)),

  if iteration == total: sys.stderr.write('\n')
  sys.stderr.flush()


def scale_to_coprime(v):
  """Scale vector to co-prime (relatively prime) integers."""
  MAX_DENOMINATOR = 1000

  def get_square_denominator(x):
    """Denominator of the square of a number."""
    return Fraction(x ** 2).limit_denominator(MAX_DENOMINATOR).denominator

  def lcm(a, b):
    """Least common multiple."""
    return a * b // np.gcd(a, b)

  denominators = [int(get_square_denominator(i)) for i in v]
  s = reduce(lcm, denominators) ** 0.5
  m = (np.array(v)*s).astype(np.int)
  return m//reduce(np.gcd,m)


class return_message():
  """Object with formatted return message."""

  def __init__(self,message):
    """
    Sets return message.

    Parameters
    ----------
    message : str or list of str
      message for output to screen

    """
    self.message = message

  def __repr__(self):
    """Return message suitable for interactive shells."""
    return srepr(self.message)


class ThreadPool:
  """Pool of threads consuming tasks from a queue."""

  class Worker(Thread):
    """Thread executing tasks from a given tasks queue."""

    def __init__(self, tasks):
      """Worker for tasks."""
      Thread.__init__(self)
      self.tasks = tasks
      self.daemon = True
      self.start()

    def run(self):
      while True:
        func, args, kargs = self.tasks.get()
        try:
          func(*args, **kargs)
        except Exception as e:
          # An exception happened in this thread
          print(e)
        finally:
          # Mark this task as done, whether an exception happened or not
          self.tasks.task_done()


  def __init__(self, num_threads):
    """
    Thread pool.

    Parameters
    ----------
    num_threads : int
      number of threads

    """
    self.tasks = Queue(num_threads)
    for _ in range(num_threads):
      self.Worker(self.tasks)

  def add_task(self, func, *args, **kargs):
    """Add a task to the queue."""
    self.tasks.put((func, args, kargs))

  def map(self, func, args_list):
    """Add a list of tasks to the queue."""
    for args in args_list:
      self.add_task(func, args)

  def wait_completion(self):
    """Wait for completion of all the tasks in the queue."""
    self.tasks.join()