from elasticsearch import Elasticsearch
from typing import List, Tuple, Dict, Any
from app.config import settings

class FulltextSearch:
    def __init__(self):
        self.es = Elasticsearch([f"http://{settings.ELASTICSEARCH_HOST}:{settings.ELASTICSEARCH_PORT}"])
        self.index_name = "documents"
        self._create_index()

    def _create_index(self):
        if not self.es.indices.exists(index=self.index_name):
            self.es.indices.create(
                index=self.index_name,
                body={
                    "settings": {
                        "analysis": {
                            "analyzer": {
                                "ru_en": {
                                    "type": "custom",
                                    "tokenizer": "standard",
                                    "filter": ["lowercase", "ru_stop", "ru_stem"]
                                }
                            },
                            "filter": {
                                "ru_stop": {
                                    "type": "stop",
                                    "stopwords": "_russian_"
                                },
                                "ru_stem": {
                                    "type": "stemmer",
                                    "language": "russian"
                                }
                            }
                        }
                    },
                    "mappings": {
                        "properties": {
                            "doc_id": {"type": "keyword"},
                            "text": {"type": "text", "analyzer": "ru_en"},
                            "title": {"type": "text", "analyzer": "ru_en"},
                            "source": {"type": "keyword"},
                            "lang": {"type": "keyword"},
                            "url": {"type": "keyword"}
                        }
                    }
                }
            )

    def index_document(self, doc_id: str, title: str, text: str, source: str, lang: str, url: str = ""):
        self.es.index(
            index=self.index_name,
            id=doc_id,
            body={
                "doc_id": doc_id,
                "title": title,
                "text": text,
                "source": source,
                "lang": lang,
                "url": url
            }
        )

    def search(self, query: str, top_k: int = 10, lang: str = None) -> List[Dict[str, Any]]:
        must = {
            "multi_match": {
                "query": query,
                "fields": ["text^2", "title^3"],
                "type": "best_fields",
                "analyzer": "ru_en",
            }
        }

        if lang:
            search_body = {
                "size": top_k,
                "query": {
                    "bool": {
                        "must": must,
                        "filter": {"term": {"lang": lang}},
                    }
                },
            }
        else:
            search_body = {"size": top_k, "query": must}

        results = self.es.search(index=self.index_name, body=search_body)
        
        formatted_results = []
        for hit in results['hits']['hits']:
            source = hit['_source']
            formatted_results.append({
                "doc_id": source['doc_id'],
                "title": source['title'],
                "source": source['source'],
                "url": source.get('url', ''),
                "score": hit['_score']
            })
        
        return formatted_results

    def search_phrase(self, phrase: str, top_k: int = 10) -> List[Dict[str, Any]]:
        results = self.es.search(
            index=self.index_name,
            body={
                "size": top_k,
                "query": {
                    "match_phrase": {
                        "text": phrase
                    }
                }
            }
        )
        
        formatted_results = []
        for hit in results['hits']['hits']:
            source = hit['_source']
            formatted_results.append({
                "doc_id": source['doc_id'],
                "title": source['title'],
                "source": source['source'],
                "url": source.get('url', ''),
                "score": hit['_score']
            })
        
        return formatted_results

    def bulk_index(self, documents: List[Dict[str, Any]]):
        actions = []
        for doc in documents:
            actions.append({"index": {"_index": self.index_name, "_id": doc['doc_id']}})
            actions.append(doc)
        
        from elasticsearch.helpers import bulk
        bulk(self.es, actions)