#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""\
Circular plate
"""
from __future__ import absolute_import, division, print_function, unicode_literals
from math import sqrt

__author__ = "Daniel Weschke"
__copyright__ = "Copyright 2019 Daniel Weschke"
__credits__ = ["Daniel Weschke"]
__license__ = "MIT"
__version__ = "2019.01.17"
__maintainer__ = "Daniel Weschke"
__email__ = "daniel.weschke@directbox.de"
__status__ = "Production"  # "Prototype", "Development", "Production"

VERSION = """\
%(prog)s version {version} {copyright}

For Unicode characters check the file encoding that the console is using.
Windows user may execute the command "chcp 65001".""".format(
  version=__version__, copyright=__copyright__)

EPILOG = """\
"""

def deflection_pinned(p, r, nu, E, t):
  """\
  Central deflection of a pinned supported circular plate.

  p   pressure
  r   radius
  nu  Poisson's ratio
  E   Young's modulus
  t   thickness
  """
  return p*r**4*(5+nu)/(64*(1+nu))*(12*(1-nu**2))/(E*t**3)

def deflection_clamped(p, r, nu, E, t):
  """\
  Central deflection of a clamped supported circular plate.

  p   pressure
  r   radius
  nu  Poisson's ratio
  E   Young's modulus
  t   thickness
  """
  return p*r**4*(1)/(64)*(12*(1-nu**2))/(E*t**3)

def thickness_min(p, d, Rp02, S):
  """\
  Minimum thickness of a circular plate.

  p     pressure
  d     diameter
  Rp02  mechanical strength
  S     safety factor
  """
  return 0.554*d*sqrt(p*S/Rp02)

def allowable_stress(sigma, S):
  """\
  Allowable stress.

  sigma  stress
  S      safety factor
  """
  return sigma/S

def main():
  """\
  Main function
  """
  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='', dest='case')
  parser_a = subparsers.add_parser(
    'deflection', help="central deflection", prefix_chars='-',
    description="Central deflection of a circular plate.")
  parser_a.add_argument('P', nargs='?', type=float, default=0.1, help='pressure [default: 0.1 (MPa = 1 bar)]')
  parser_a.add_argument('NU', type=float, help='Poisson\'s ratio (CVD diamond 0.1)')
  parser_a.add_argument('R', type=float, help='radius')
  parser_a.add_argument('E', type=float, help='Young\'s modulus (CVD diamond 1.05e6)')
  parser_a.add_argument('T', type=float, help='thickness')
  parser_a.add_argument('-p', '--pinned', action="store_true", help='pinned support')
  parser_a.add_argument('-c', '--clamped', action="store_true", help='clamped support')
  parser_b = subparsers.add_parser(
    'thickness', help="minimum thickness", prefix_chars='-',
    description="Minimum thickness of a circular plate.")
  parser_b.add_argument('P', nargs='?', type=float, default=0.1, help='pressure [default: 0.1 (MPa = 1 bar)]')
  parser_b.add_argument('D', type=float, help='diameter')
  parser_b.add_argument('SIG', type=float, help='mechanical strength (CVD diamond 2000..400)')
  parser_b.add_argument('S', nargs='?', type=float, default=4., help='safety factor [default: 4]')
  args = parser.parse_args()

  if args.debug:
    print(args)

  if args.case == 'deflection':
    if args.pinned:
      print(deflection_pinned(args.P, args.R, args.NU, args.E, args.T))
    elif args.clamped:
      print(deflection_clamped(args.P, args.R, args.NU, args.E, args.T))
    else:
      print('error: define a support type.')
      return 2
  elif args.case == 'thickness':
    print(thickness_min(args.P, args.D, args.SIG, args.S))

  return 0

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