"""Common helper functions for running the tests.

Copyright (C) 2013, Joshua More and Michele Ceriotti

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http.//www.gnu.org/licenses/>.


Functions:
   local: Returns local folder of the tests directory.

Classes:
   TestSimulation: Can be used to test that a particular simulation
      will run properly, given an input file and a driver code.
"""

import glob
import os
import subprocess
import shutil
import tempfile

def local(file=None):
    """Returns local folder of the tests directory.

    Args:
        - file: Append file to the local folder
    """
    if file:
        return os.sep.join(__file__.split(os.sep)[:-1]+[file])
    else:
        return os.sep.join(__file__.split(os.sep)[:-1])

class TestSimulation(object):
   """Simple class used to test various aspects of the simulation.

   Can be used to run an example given the location of an xml
   input file and the location of a suitable driver code.

   Attributes:
      finput: The name of the xml input file
      folder_input: A string giving the directory the input file is held in.
      fdriver: The location of a driver code.
      cwd: Current working directory.
      tmpdir: A temporary directory to run the simulation in.
   """

   def __init__(self, input, driver):
      """Initializes TestSimulation.

      Args:
         input: The name of the xml input file.
         driver: The location of the driver code.
      """

      self.finput = input
      self.folder_input = os.sep.join(input.split(os.sep)[:-1])
      self.fdriver = driver
      self.cwd = os.getcwd()
      self.tmpdir = tempfile.mkdtemp()

      # Copy needed files to tmpdir
      for src in glob.glob("%s/*"%self.folder_input):
          shutil.copy(src, self.tmpdir)

      os.chdir(self.tmpdir)

   def __del__(self):
      """Cleans the temporary directory once the simulation is over."""

      os.chdir(self.cwd)
      shutil.rmtree(self.tmpdir)

   def run(self):
      """Runs the simulation."""

      # Run driver
      p = subprocess.Popen("echo running %s"%self.fdriver, shell=True)

      # Start simulation
      # TODO
      print subprocess.check_output("ls", shell=True)
      print subprocess.check_output("pwd", shell=True)

      # wait for driver to finish
      p.wait()