#! /usr/bin/env python

# These methods are used by test.py and waf to look for and read the

# .ns3rc configuration file, which is used to specify the modules that

# should be enabled

import os

import sys

def get_list_from_file(file_path, list_name):

    '''Looks for a Python list called list_name in the file specified

    by file_path and returns it.

    If the file or list name aren't found, this function will return

    an empty list.

    '''

    list = []

    # Read in the file if it exists.

    if os.path.exists(file_path):

        file_in = open(file_path, "r")

        # Look for the list.

        list_string = ""

        parsing_multiline_list = False

        for line in file_in:

            # Remove any comments.

            if '#' in line:

                (line, comment) = line.split('#', 1)

            # Parse the line.

            if list_name in line or parsing_multiline_list:

                list_string += line

                # Handle multiline lists.

                if ']' not in list_string:

                    parsing_multiline_list = True

                else:

                    # Evaluate the list once its end is reached.

                    # Make the split function only split it once.

                    list = eval(list_string.split('=', 1)[1].strip())

                    break

        # Close the file

        file_in.close()

    return list

def get_bool_from_file(file_path, bool_name, value_if_missing):

    '''Looks for a Python boolean variable called bool_name in the

    file specified by file_path and returns its value.

    If the file or boolean variable aren't found, this function will

    return value_if_missing.

    '''

    # Read in the file if it exists.

    if os.path.exists(file_path):

        file_in = open(file_path, "r")

        # Look for the boolean variable.

        bool_found = False

        for line in file_in:

            # Remove any comments.

            if '#' in line:

                (line, comment) = line.split('#', 1)

            # Parse the line.

            if bool_name in line:

                # Evaluate the variable's line once it is found.  Make

                # the split function only split it once.

                bool = eval(line.split('=', 1)[1].strip())

                bool_found = True

                break

        # Close the file

        file_in.close()

    if bool_found:

        return bool

    else:

        return value_if_missing

# Reads the NS-3 configuration file and returns a list of enabled modules.

#

# This function first looks for the ns3 configuration file (.ns3rc) in

# the current working directory and then looks in the ~ directory.

def read_config_file():

    # By default, all modules will be enabled, examples will be disabled,

    # and tests will be disabled.

    modules_enabled  = ['all_modules']

    examples_enabled = False

    tests_enabled    = False

    # See if the ns3 configuration file exists in the current working

    # directory and then look for it in the ~ directory.

    config_file_exists = False

    dot_ns3rc_name = '.ns3rc'

    dot_ns3rc_path = dot_ns3rc_name

    if not os.path.exists(dot_ns3rc_path):

        dot_ns3rc_path = os.path.expanduser('~/') + dot_ns3rc_name

        if not os.path.exists(dot_ns3rc_path):

            # Return all of the default values if the .ns3rc file can't be found.

            return (config_file_exists, modules_enabled, examples_enabled, tests_enabled)

    config_file_exists = True

    # Read in the enabled modules.

    modules_enabled = get_list_from_file(dot_ns3rc_path, 'modules_enabled')

    if not modules_enabled:

        # Enable all modules if the modules_enabled line can't be found.

        modules_enabled = ['all_modules']

    # Read in whether examples should be enabled or not.

    value_if_missing = False

    examples_enabled = get_bool_from_file(dot_ns3rc_path, 'examples_enabled', value_if_missing)

    # Read in whether tests should be enabled or not.

    value_if_missing = False

    tests_enabled = get_bool_from_file(dot_ns3rc_path, 'tests_enabled', value_if_missing)

    return (config_file_exists, modules_enabled, examples_enabled, tests_enabled)