from sentence_transformers import SentenceTransformer
import numpy as np
from typing import Sequence
import faiss





class Vectorizer:
    def __init__(self, model) -> None:
        """Initialize the vectorizer with a pre-trained embedding model.
        Args: model: The pre-trained embedding model to use for transforming prompts.
        """
        self.model = model
        self.index_size = 50000
        self.index = faiss.IndexFlatIP(self.index_size)
        self.cached_index_idx_to_retrieval_db_idx = []
    

    def transform_and_add_to_index(self, prompts: Sequence[str]) -> np.ndarray:  
        """Transform texts into numerical vectors using the specified model.
        Args: prompts: The sequence of raw corpus prompts. Returns: Vectorized prompts
        """
        embeddings = self.model.encode(prompts)
        embedding_dimension = embeddings.shape[1]
        print('Embedding dimension:', embedding_dimension)
        
        self.index.add(np.array(embeddings))