import logging
import os
from typing import List, Optional
from opensearchpy import OpenSearch, RequestsHttpConnection
from core.config import settings
from core.models import DocumentChunk

logger = logging.getLogger("Retriever")


class SearchRetriever:
    def __init__(self, index_name: str = "poc_sharepoint_docs"):
        self.index_name = index_name
        
        host = settings.opensearch_host
        if host == "opensearch" and os.environ.get("ENV") != "docker":
            host = "localhost"
        
        self.client = OpenSearch(
            hosts=[{'host': host, 'port': settings.opensearch_port}],
            http_auth=(settings.opensearch_user, settings.opensearch_pass),
            use_ssl=False,
            verify_certs=False,
            connection_class=RequestsHttpConnection
        )
        
        logger.info("Loading Embedding Model for Retriever...")
        from sentence_transformers import SentenceTransformer
        self.embedder = SentenceTransformer('keepitreal/vietnamese-sbert')

    def retrieve(self, query: str, top_k: int = 5, user_email: Optional[str] = None, is_admin: bool = False) -> List[DocumentChunk]:
        """
        Tìm kiếm ngữ nghĩa với ACL filtering.
        
        Args:
            query: Câu hỏi của user
            top_k: Số kết quả tối đa
            user_email: Email user để filter quyền.
            is_admin: True = bypass ACL, thấy tất cả.
        """
        logger.info(f"Search: '{query[:80]}' (user={user_email or 'none'}, admin={is_admin})")
        
        query_vector = self.embedder.encode(query).tolist()
        
        # Admin hoặc không có user_email → không filter
        if is_admin or not user_email:
            search_query = {
                "size": top_k,
                "query": {
                    "knn": {
                        "embedding": {
                            "vector": query_vector,
                            "k": top_k
                        }
                    }
                }
            }
        else:
            # User thường → filter theo permissions
            search_query = {
                "size": top_k,
                "query": {
                    "bool": {
                        "must": [
                            {
                                "knn": {
                                    "embedding": {
                                        "vector": query_vector,
                                        "k": top_k * 2
                                    }
                                }
                            }
                        ],
                        "should": [
                            {"term": {"permissions": "*"}},
                            {"term": {"permissions": user_email.lower()}}
                        ],
                        "minimum_should_match": 1
                    }
                }
            }
        
        try:
            response = self.client.search(
                index=self.index_name,
                body=search_query
            )
            
            hits = response.get("hits", {}).get("hits", [])
            results = []
            
            for hit in hits:
                source = hit["_source"]
                chunk = DocumentChunk(**source)
                results.append(chunk)
                
            logger.info(f"Found {len(results)} chunks")
            return results
            
        except Exception as e:
            logger.error(f"OpenSearch query error: {e}")
            return []