"""
Parse folder structure.

Used to parse the folder structure stored in the direct delivery asset_type.
An example of this: {upc(0,6)}/{upc(6,3)}/{upc}

Note this logic is taken from:
    https://github.com/theorchard/common/blob/master/src/ParseFileName.php
It should be abstracted from here and put into a common microservice
"""
import re


def split_folder_structure_string(folder_str):
    """Split string based on pattern used in folder structure.

    Args:
        folder_str (string): folder structure found in the asset_type table
    Returns:
        split_list (list): list of location parsed from the folder structure
    """
    pattern = '({(?:[^{}]+(?:"[^"]*"|\'[^\']*\')?)+})'
    split_list = re.split(pattern, folder_str)
    split_list = list(filter(None, split_list))
    return split_list


def is_variable(folder_str):
    """Determine if a string contains a variable, denoted by brackets.

    Args:
        folder_str (string): string that could possibly represent a variable
    Returns:
        boolean: whether the string is in the format of a variable
    """
    pattern = '{.*}$'
    matches = re.search(pattern, folder_str)
    if matches is not None:
        return True
    else:
        return False


def process_string(original_str, variables_dict):
    """Compose a new string with variables inserted.

    Args:
        original_str (string): string to insert variables into
        variables_dict (dict): dict of variables to insert
            i.e. {'asset_id': 12345, 'upc': 1234567890}
    Returns:
        return_str (string): new string with the variables inserted
    """
    breakdown = split_folder_structure_string(original_str)
    return_str = ''
    for tmp_str in breakdown:
        if is_variable(tmp_str):
            tmp_str = tmp_str.strip('{')
            tmp_str = tmp_str.strip('}')
            len_vars = '0'
            if '(' in tmp_str:
                var_name, len_vars = tmp_str.split('(')
            else:
                var_name = tmp_str

            var_value = str(variables_dict[var_name])
            if (len(len_vars) == 0):
                return_str += var_value
            else:
                len_vars = len_vars.strip(')')
                len_vars_arr = len_vars.split(',')
                if (len(len_vars_arr) == 1):
                    new_val = '%0' + len_vars_arr[0] + 's'
                    return_str += new_val % (var_value)
                else:
                    var_start = int(len_vars_arr[0])
                    var_end = int(len_vars_arr[0]) + int(len_vars_arr[1])
                    return_str += var_value[var_start:var_end]
        else:
            return_str += tmp_str
    return return_str