import os
import subprocess
import sys

import json

from itertools import product

def tail_lines(s, n, f=3):
  ss = s.split('\n')
  if len(ss) > n*f:
    return '\n'.join(["... {} lines ...".format(len(ss)-n)] + ss[-n:])
  return s

def run_fw(config_filepath, env):
  cmd = './framework.exe {} -m pre'.format(config_filepath)
  try:
    print("Running Framework...")
    cp = subprocess.run(cmd, capture_output=True, check=True, shell=True, text=True, env=env)
    print("__STDOUT__\n" + tail_lines(cp.stdout, 10))
    #print("__STDERR__\n" + tail_lines(cp.stderr, 5))
  except subprocess.CalledProcessError as e:
    print("__STDOUT__\n" + tail_lines(e.stdout, 10))
    print("__STDERR__\n" + tail_lines(e.stderr, 10))
    print("Error in Framework :-/\n")
    return False
  else:
    print("Success!\n")
    return True

# This is for convenience in writing environment JSON files,
#   so that length-one arrays can just be the one null/string value.
inline_list = lambda s: s if isinstance(s, list) else [s]

def iter_space(space):
  var, span = space.keys(), space.values()
  span = map(inline_list, span)
  # span is now a list of lists
  # Iterate over every combination
  for _v in product(*span):
    # Construct the environment dictionary and return it
    yield dict(zip(var, _v))

def main(config_filepath, env_space):
  n_success = 0
  total = 0
  for _env in iter_space(env_space):
    #env = os.environ.copy()  # Not recommended
    env = dict()
    for k, v in _env.items():
      if v is None:
        if k in env:
          del env[k]
      else:
        print(">>> {}={}".format(k, v or ''))
        env[k] = v
    ret = run_fw(config_filepath, env)
    n_success += ret
    total += 1
  print("{} out of {} runs were successful".format(n_success, total))

if __name__ == '__main__':
  if len(sys.argv) < 3:
    print("Usage: python configuration_test.py config.xml env.json")
    sys.exit()
  config_filepath = sys.argv[1]
  with open(sys.argv[2], 'r') as f:
    env_space = json.load(f)
  main(config_filepath, env_space)