#    This file is part of cfelpyutils.
#
#    cfelpyutils 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.
#
#    cfelpyutils 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 cfelpyutils.  If not, see <http://www.gnu.org/licenses/>.
"""
Utilities for parsing command line options and configuration files.

This module contains utilities for parsing of command line options and
configuration files.
"""

from __future__ import (absolute_import, division, print_function,
                        unicode_literals)

import ast


def parse_parameters(config):
    """Sets correct types for parameter dictionaries.

    Reads a parameter dictionary returned by the ConfigParser python module, and assigns correct types to parameters,
    without changing the structure of the dictionary.

    The parser tries to interpret each entry in the dictionary according to the following rules:

    - If the entry starts and ends with a single quote or double quote, it is
      interpreted as a string.
    - If the entry starts and ends with a square bracket, it is interpreted as a list.
    - If the entry starts and ends with a brace, it is interpreted as a dictionary.
    - If the entry is the word None, without quotes, then the entry is
      interpreted as NoneType.
    - If the entry is the word False, without quotes, then the entry is
      interpreted as a boolean False.
    - If the entry is the word True, without quotes, then the entry is
      interpreted as a boolean True.
    - If none of the previous options match the content of the entry,
      the parser tries to interpret the entry in order as:

        - An integer number.
        - A float number.
        - A string.

      The first choice that succeeds determines the entry type.

    Args:

        config (class RawConfigParser): ConfigParser instance.

    Returns:

        monitor_params (dict): dictionary with the same structure as the input dictionary, but with correct types
        assigned to each entry.
    """

    monitor_params = {}

    for sect in config.sections():
        monitor_params[sect] = {}
        for op in config.options(sect):
            monitor_params[sect][op] = config.get(sect, op)
            if monitor_params[sect][op].startswith("'") and monitor_params[sect][op].endswith("'"):
                monitor_params[sect][op] = monitor_params[sect][op][1:-1]
                continue
            if monitor_params[sect][op].startswith('"') and monitor_params[sect][op].endswith('"'):
                monitor_params[sect][op] = monitor_params[sect][op][1:-1]
                continue
            if monitor_params[sect][op].startswith("[") and monitor_params[sect][op].endswith("]"):
                try:
                    monitor_params[sect][op] = ast.literal_eval(config.get(sect, op))
                    continue
                except (SyntaxError, ValueError):
                    raise RuntimeError('Error parsing parameter {0} in section [{1}]. Make sure that the syntax is '
                                       'correct: list elements must be separated by commas and dict entries must '
                                       'contain the colon symbol. Strings must be quoted, even in lists and '
                                       'dicts.'.format(op, sect))
            if monitor_params[sect][op].startswith("{") and monitor_params[sect][op].endswith("}"):
                try:
                    monitor_params[sect][op] = ast.literal_eval(config.get(sect, op))
                    continue
                except (SyntaxError, ValueError):
                    raise RuntimeError('Error parsing parameter {0} in section [{1}]. Make sure that the syntax is '
                                       'correct: list elements must be separated by commas and dict entries must '
                                       'contain the colon symbol. Strings must be quoted, even in lists and '
                                       'dicts.'.format(op, sect))
            if monitor_params[sect][op] == 'None':
                monitor_params[sect][op] = None
                continue
            if monitor_params[sect][op] == 'False':
                monitor_params[sect][op] = False
                continue
            if monitor_params[sect][op] == 'True':
                monitor_params[sect][op] = True
                continue
            try:
                monitor_params[sect][op] = int(monitor_params[sect][op])
                continue
            except ValueError:
                try:
                    monitor_params[sect][op] = float(monitor_params[sect][op])
                    continue
                except ValueError:
                    raise RuntimeError('Error parsing parameter {0} in section [{1}]. Make sure that the syntax is '
                                       'correct: list elements must be separated by commas and dict entries must '
                                       'contain the colon symbol. Strings must be quoted, even in lists and '
                                       'dicts.'.format(op, sect))
    return monitor_params