#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""\
Material database.
"""
__author__ = "Daniel Weschke"
__copyright__ = "Copyright 2019 Daniel Weschke"
__credits__ = ["Daniel Weschke"]
__license__ = "MIT"
__version__ = "2019.02.03"
__maintainer__ = "Daniel Weschke"
__email__ = "daniel.weschke@directbox.de"
__status__ = "Production"  # "Prototype", "Development", "Production"

VERSION = """\
%(prog)s version {version} {copyright}
""".format(
  version=__version__, copyright=__copyright__)

EPILOG = """\
"""


def read_dir(dir, exclude=[]):
  """\
  Read all files in directory as list
  """
  from os import listdir

  result = []
  for data in listdir(dir):
    file_name = data.split('.')[0]
    if file_name not in exclude:
      result.append(file_name)
  return result


def print_list(list):
  """\
  Print list
  """
  for data in list:
    print(data.title())


def read_file(input_file):
  """\
  Read file as string
  """
  try:
    with open(input_file) as data_file:
      return data_file.read()
  except (OSError, IOError) as err:
    print(str(err))
    sys.exit(2)


def print_data(data):
  """\
  Convert string data to json data and print it.
  """
  from json import loads
  from pprint import pprint

  #print(data)
  pprint(loads(data))


def search_keys(data, keys=None):
  """\
  Search for json keys in string data
  """
  from json import loads

  def find_values(key, json_repr):
    results = []
    def _decode_dict(a_dict):
      try:
        results.append(a_dict[key])
      except KeyError:
        pass
      return a_dict

    loads(json_repr, object_hook=_decode_dict)  # return value ignored
    return results

  if keys is not None:
    for key in keys:
      found_values = find_values(key, data)
      #print(found_values)
      for value in found_values:
        print(key + ' = ' + '%s' % value[0] + ' ' + value[1])

    #def getLength(element):
    #  try:
    #    element.__iter__
    #    return sum([getLength(i) for i in element])
    #  except:
    #    return 1
    #print(len(data))
    #print(getLength(json.loads(data)))


def main():
  """\
  Main function
  """
  from os import path
  import argparse

  parser = argparse.ArgumentParser(
    description=__doc__, prefix_chars='-', epilog=EPILOG,
    #usage="%(prog)s [OPTION]... NAME",
    formatter_class=argparse.RawTextHelpFormatter,
  )
  parser.add_argument('-v', '--verbose', action="store_true", help="Verbose output")
  parser.add_argument('-V', '--version', action='version', version=VERSION)
  parser.add_argument('-D', '--debug', dest='debug', action='store_true', help=argparse.SUPPRESS)

  subparsers = parser.add_subparsers(help='commands', dest='command')

  # list materials
  parser_list = subparsers.add_parser('list',
                                      description='List materials.',
                                      help='list all available materials')

  # material
  parser_material = subparsers.add_parser('get',
                                          description='Get material information.',
                                          help='get material information')
  parser_material.add_argument('materialname', action='store',
                               help='list available material information')
  parser_material.add_argument('-r', '--rho', dest='const_collection',
                               action='append_const', const="rho",
                               help='get density from material')
  parser_material.add_argument('-T', '--Tm', dest='const_collection',
                               action='append_const', const="T_m",
                               help='get melting point temperature')

  args = parser.parse_args()

  if args.debug:
    print(args)

  if args.command == 'list':
    list = read_dir("./data", "INFO")
    print_list(list)

  elif args.command == 'get':
    filename = path.join('data', args.materialname + '.json')
    if args.debug:
      print("filename: " + filename)
    if args.const_collection:
      data = read_file(filename)
      search_keys(data, keys=args.const_collection)
    else:
      data = read_file(filename)
      print_data(data)

  return 0


if __name__ == "__main__":
  import sys
  sys.exit(main())