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from fnmatch import fnmatch


async def deleteindex(es, params):
    """
    Deletes all indices in Elasticsearch matching either the specified index pattern or
    the suffix of the index against a more complex pattern.

    :param es: Specifies the index pattern to delete. Defaults to 'elasticlogs-*'
    :type es: str
    :param params: Parameter hash containing one of the keys documented below.
    :type params: dict

        "index_pattern"        - Mandatory.
                                 Specifies the index pattern to delete.
        "max_indices"          - Optional.
                                 int specifying how many rolled over indices to retain at max.
                                 The elibigle indices need to satisfy `index-pattern`.
                                 'suffix_separator' is used to retrieve the integer suffixes to calculate indices to delete.

                                 Example:
                                    For the indices: 'elasticlogs-000001', 'elasticlogs-000002', ... 000011
                                    (index currently written to is 'elasticlogs-000011')

                                    using:
                                        suffix_separator='-' and
                                        max_indices=8

                                    will result in deleting indices 'elasticlogs-000001' and 'elasticlogs-000002'
        "suffix_separator"     - Defaults to '-'. Used only when 'max_indices' is specified.
                                 Specifies string separator used to extract the index suffix, e.g. '-'.


    """
    def get_suffix(name, separator):
        if separator in name:
            name_parts = name.split(separator)
            if len(name_parts) > 1:
                try:
                    return int(name_parts[-1])
                except ValueError:
                    # TODO: log that suffix is not integer
                    return None
        return None

    index_pattern = params["index_pattern"]
    max_indices = params.get("max_indices", None)
    suffix_separator = params.get("suffix_separator", "-")

    if max_indices:
        indices = await es.cat.indices(h="index")
        if isinstance(indices, bytes):
            indices = indices.decode("utf-8")
        indices = indices.split("\n")
        indices_by_suffix = {get_suffix(idx, suffix_separator): idx
            for idx in indices
            if fnmatch(idx, index_pattern) and
            get_suffix(idx, suffix_separator) is not None
        }

        sorted_suffixes = sorted(list(indices_by_suffix.keys()))
        if len(sorted_suffixes) > max_indices:
            indices_to_delete = ",".join([indices_by_suffix[key] for key in sorted_suffixes[:(len(sorted_suffixes)-max_indices)]])
            await es.indices.delete(indices_to_delete)
    else:
        await es.indices.delete(index=index_pattern)

    return 1, "ops"