#!/usr/bin/env python

from __future__ import print_function

import os
import sys


def msg_checking(msg):
  print('Checking {0}... '.format(msg), end='')


def execute(cmd, display=0):
  if display:
    print(cmd)
  return os.system(cmd)


def run_test(inp, flags=''):
  try:
    tmp = open('_temp.c', 'w')
    tmp.write(inp)
    tmp.close()
    compile_cmd = '%s -o _temp _temp.c %s' % (os.environ.get('CC', 'cc'),
                                              flags)
    if not execute(compile_cmd):
      execute('./_temp')
  finally:
    execute('rm -f _temp.c _temp')

MAD_TEST_PROGRAM = '''
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mad.h>

int main ()
{
  system("touch conf.madtest");
  return 0;
}
'''


def find_mad(mad_prefix='/usr/local', enable_madtest=1):
  """A rough translation of mad.m4"""

  mad_include_dir = mad_prefix + '/include'
  mad_lib_dir = mad_prefix + '/lib'

  msg_checking('for MAD')

  if enable_madtest:
    execute('rm -f conf.madtest', 0)

    try:
      run_test(MAD_TEST_PROGRAM, flags='-I' + mad_include_dir)
      if not os.path.isfile('conf.madtest'):
        raise RuntimeError('Did not produce output')
      execute('rm conf.madtest', 0)

    except:
      print('test program failed')
      return None

  print('success')

  return {'library_dirs': mad_lib_dir,
          'include_dirs': mad_include_dir}


def write_data(data):
  setup_file = open('setup.cfg', 'w')
  setup_file.write('[build_ext]\n')
  for item in list(data.items()):
    setup_file.write('%s=%s\n' % item)
  setup_file.close()
  print('Wrote setup.cfg file')


def print_help():
  print('''%s
    --prefix      Give the prefix in which MAD was installed.''' % sys.argv[0])
  sys.exit(0)


def parse_args():
  data = {}
  argv = sys.argv
  for pos in range(len(argv)):
    if argv[pos] == '--help':
      print_help()
    if argv[pos] == '--prefix':
      pos = pos + 1
      if len(argv) == pos:
        print('Prefix needs an argument')
        sys.exit(1)
      data['prefix'] = argv[pos]

  return data


def main():
  args = parse_args()
  prefix = args.get('prefix', '/usr/local')

  data = find_mad(mad_prefix=prefix)
  if not data:
    print('Config failure')
    sys.exit(1)
  write_data(data)

if __name__ == '__main__':
  main()