core/services/search.py

import json
import logging
import os

from opensearchpy import OpenSearch

from services.rediscache import redis


logger = logging.getLogger('[services.search] ')
logger.setLevel(logging.DEBUG)

ELASTIC_HOST = (
    os.environ.get('ELASTIC_HOST', 'localhost')
    .replace('https://', '')
    .replace('http://', '')
)
ELASTIC_USER = os.environ.get('ELASTIC_USER', '')
ELASTIC_PASSWORD = os.environ.get('ELASTIC_PASSWORD', '')
ELASTIC_PORT = os.environ.get('ELASTIC_PORT', 9200)
ELASTIC_AUTH = f'{ELASTIC_USER}:{ELASTIC_PASSWORD}' if ELASTIC_USER else ''
ELASTIC_URL = os.environ.get(
    'ELASTIC_URL', f'https://{ELASTIC_AUTH}@{ELASTIC_HOST}:{ELASTIC_PORT}'
)
REDIS_TTL = 86400  # 1 day in seconds


class SearchService:
    def __init__(self, index_name='posts'):
        logger.info('initialized')
        self.index_name = index_name
        self.disabled = False
        try:
            self.client = OpenSearch(
                hosts=[{'host': ELASTIC_HOST, 'port': ELASTIC_PORT}],
                http_compress=True,
                http_auth=(ELASTIC_USER, ELASTIC_PASSWORD),
                use_ssl=True,
                verify_certs=False,
                ssl_assert_hostname=False,
                ssl_show_warn=False,
                # ca_certs = ca_certs_path
            )

        except Exception as exc:
            logger.error(exc)
            self.disabled = True

        self.check_index()

    def info(self):
        logging.info(f'{self.client}')
        try:
            indices = self.client.indices.get_alias('*')
            logger.debug('List of indices:')
            for index in indices:
                logger.debug(f'- {index}')
        except Exception as e:
            logger.error(f'Error while listing indices: {e}')

    def delete_index(self):
        self.client.indices.delete(index=self.index_name, ignore_unavailable=True)

    def create_index(self):
        index_settings = {
            'settings': {
                'index': {
                    'number_of_shards': 1,
                    'auto_expand_replicas': '0-all',
                },
                'analysis': {
                    'analyzer': {
                        'ru': {
                            'tokenizer': 'standard',
                            'filter': ['lowercase', 'ru_stop', 'ru_stemmer'],
                        }
                    },
                    'filter': {
                        'ru_stemmer': {
                            'type': 'stemmer',
                            'language': 'russian',
                        },
                        'ru_stop': {
                            'type': 'stop',
                            'stopwords': '_russian_',
                        },
                    },
                },
            },
            'mappings': {
                'properties': {
                    'body': {'type': 'text', 'analyzer': 'ru'},
                    'text': {'type': 'text'},
                    'author': {'type': 'text'},
                }
            },
        }
        try:
            self.client.indices.create(index=self.index_name, body=index_settings)
            self.client.indices.close(index=self.index_name)
            self.client.indices.open(index=self.index_name)
        except Exception as error:
            logger.warn(error)

    def put_mapping(self):
        mapping = {
            'properties': {
                'body': {'type': 'text', 'analyzer': 'ru'},
                'text': {'type': 'text'},
                'author': {'type': 'text'},
            }
        }

        self.client.indices.put_mapping(index=self.index_name, body=mapping)

    def check_index(self):
        if not self.client.indices.exists(index=self.index_name):
            logger.debug(f'Creating {self.index_name} index')
            self.create_index()
            self.put_mapping()
        else:
            # Check if the mapping is correct, and recreate the index if needed
            mapping = self.client.indices.get_mapping(index=self.index_name)
            expected_mapping = {
                'properties': {
                    'body': {'type': 'text', 'analyzer': 'ru'},
                    'text': {'type': 'text'},
                    'author': {'type': 'text'},
                }
            }
            if mapping != expected_mapping:
                logger.debug(
                    f'Recreating {self.index_name} index due to incorrect mapping'
                )
                self.recreate_index()

    def recreate_index(self):
        self.delete_index()
        self.check_index()

    def index_post(self, shout):
        id_ = str(shout.id)
        logger.debug(f'Indexing post id {id_}')
        self.client.index(index=self.index_name, id=id_, body=shout)

    def search_post(self, query, limit, offset):
        logger.debug(f'query: {query}')
        search_body = {
            'query': {'match': {'_all': query}},
        }

        search_response = self.client.search(
            index=self.index_name, body=search_body, size=limit, from_=offset
        )
        hits = search_response['hits']['hits']

        return [
            {
                **hit['_source'],
                'score': hit['_score'],
            }
            for hit in hits
        ]


search = SearchService()


async def search_text(text: str, limit: int = 50, offset: int = 0):
    payload = []
    try:
        # Use a key with a prefix to differentiate search results from other Redis data
        redis_key = f'search:{text}'
        if not search.disabled:
            # Use OpenSearchService.search_post method
            payload = search.search_post(text, limit, offset)
            # Use Redis as cache with TTL
            await redis.execute('SETEX', redis_key, REDIS_TTL, json.dumps(payload))
    except Exception as e:
        logging.error(f'Error during search: {e}')
    return payload