import logging
from typing import Union, List

from elasticsearch import Elasticsearch
import elasticsearch.helpers # type: ignore

from towhee.operator import PyOperator, SharedType # type: ignore


logger = logging.getLogger()


class ESIndex(PyOperator):
    """
    Use bulk to insert docs into ElasticSearch index, using auto id generated.

    Args:
        host (`str`): host to connect ElasticSearch client
        port (`int`): port to connect ElasticSearch client
        user (`str=None`): user name to connect ElasticSearch client, defaults to None
        password (`str=None`): user password to connect ElasticSearch client, defaults to None
        ca_certs (`str=None`): path to CA certificate, defaults to None
    """
    def __init__(self, **connection_kwargs):
        super().__init__()
        try:
            if 'port' in connection_kwargs:
                assert 'host' in connection_kwargs, 'Missing port in connection kwargs but given port only.'
                connection_kwargs['hosts'] = [f'https://{host}:{port}']
            self.client = Elasticsearch(**connection_kwargs)
            logger.info('Successfully connected to ElasticSearch client.')
        except Exception as e:
            logger.error('Failed to connect ElasticSearch client:\n', e)
            raise e


    def __call__(self, index_name: str, doc: Union[dict, List[dict]]):
        # if index not exist, create with stop words analyzer to strengthen the search accuracy
        if not self.is_index_exist(index_name):
            self.create_index(index_name)
        if isinstance(doc, dict):
            docs = [doc]
        else:
            docs = doc

        for x in docs:
            assert isinstance(x, dict)

        actions = [
            {
                '_op_type': 'index',
                '_index': index_name,
                '_source': d
            }
            for d in docs
        ]
        res = elasticsearch.helpers.bulk(self.client, actions, refresh=True)
        return res

    def is_index_exist(self, index_name: str):
        return self.client.indices.exists(index=index_name)

    def create_index(self, index_name: str):
        settings = {
            "analysis": {"analyzer": {"default": {"type": "standard"}}},
            "similarity": {
                "custom_bm25": {
                    "type": "BM25",
                    "k1": 2.0,
                    "b": 0.75,
                }
            },
        }
        mappings = {
            "properties": {
                "sentence": {
                    "type": "text",
                    "similarity": "custom_bm25",  # Use the custom BM25 similarity
                }
            }
        }

        # Create the index with the specified settings and mappings
        self.client.indices.create(index=index_name, mappings=mappings, settings=settings)