#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# This file is part of CERN Search.
# Copyright (C) 2018-2019 CERN.
#
# Citadel Search is free software; you can redistribute it and/or modify it
# under the terms of the MIT License; see LICENSE file for more details.

"""Helper methods for CERN Search records."""

from elasticsearch import VERSION as ES_VERSION
from flask import current_app, g
from flask_login import current_user
from invenio_indexer.utils import default_record_to_index, schema_to_index
from invenio_search import current_search, current_search_client
from invenio_search.utils import prefix_index


def get_user_provides():
    """Extract the user's provides from g."""
    current_app.logger.debug(f'Identity: {g.identity}')
    current_app.logger.debug(f'Current User: {current_user}')

    return [need.value for need in g.identity.provides]


def record_from_index(record):
    """Get index/doc_type given a record.

    It tries to extract from `record['$schema']` the index and doc_type.
    If it fails, return the default values.

    :param record: The record object.
    :returns: Tuple (index, doc_type).
    """
    index_names = current_search.mappings.keys()
    schema = record.get('metadata').get('$schema', '')
    if isinstance(schema, dict):
        schema = schema.get('$ref', '')

    index, doc_type = schema_to_index(schema, index_names=index_names)

    if index and doc_type:
        return index, doc_type
    else:
        return (current_app.config['INDEXER_DEFAULT_INDEX'],
                current_app.config['INDEXER_DEFAULT_DOC_TYPE'])


def default_record_to_mapping(record):
    """Get mapping given a record.

    It tries to extract from `record['$schema']` the index and doc_type.
    If it fails, uses the default values.

    :param record: The record object.
    :returns: mapping
    """
    index, doc = default_record_to_index(record)
    index = prefix_index(index)
    current_app.logger.debug('Using index {idx} and doc {doc}'.format(idx=index, doc=doc))

    mapping = current_search_client.indices.get_mapping([index])
    if mapping is not None:
        doc_type = next(iter(mapping))
        current_app.logger.debug('Using mapping for {idx}'.format(idx=index))
        current_app.logger.debug('Mapping {mapping}'.format(mapping=mapping))

        if ES_VERSION[0] >= 7:
            return mapping[doc_type]['mappings']

        return mapping[doc_type]['mappings'][doc]

    return None


def reverse_dict_list(org):
    """Reverses dict {a: [b,c]} to {b:a, c:a}."""
    newdict = {}
    for key, value in org.items():
        for string in value:
            newdict[string] = key
    return newdict