"""
    Utility functions for the library
"""

def sorted_params_string(filters_dict):
    """
    This function takes a dict and returns it in a sorted form for the url
    filter, it's primarily used for cache purposes.
    """
    filters_string = ''
    for key in sorted(filters_dict.keys()):
        if filters_string == '':
            key_str = ','.join(str(val) for val in sorted(filters_dict[key]))
            filters_string = f"{key}={key_str}"
        else:
            key_str = ','.join(str(val) for val in sorted(filters_dict[key]))
            filters_string = f"{filters_string}&{key}={key_str}"
        filters_string = filters_string.strip()
    return filters_string


def parse_tags_to_dict(tags):
    " This function parses a tag string into a dictionary "
    tagdict = {}
    if ':' not in tags:
        tagdict = {}
    else:
        for subtag in tags.split('&'):
            tagkey, taglist = subtag.split(':')
            taglist = taglist.split(',')
            tagdict[tagkey] = set(taglist)
    return tagdict