import dataclasses
import math
from typing import List, Optional

import torch
from pymilvus import MilvusClient, connections
from transformers import AutoModel, AutoTokenizer

from credentials import get_token


@dataclasses.dataclass
class MilvusParams:
    uri: str
    token: str
    db_name: str
    collection_name: str


class ProteinSearchEngine:
    n_dims = 128
    dist_metric = "euclidean"
    max_lengths = (30, 300)

    def __init__(self, milvus_params: MilvusParams, model_repo: str):
        self.model_repo = model_repo
        self.milvus_params = milvus_params
        connections.connect(
            "default",
            uri=milvus_params.uri,
            token=milvus_params.token,
            db_name=milvus_params.db_name,
        )
        self.client = MilvusClient(uri=milvus_params.uri, token=milvus_params.token)
        self.tokenizer = AutoTokenizer.from_pretrained(
            self.model_repo, use_auth_token=get_token()
        )
        self.model = AutoModel.from_pretrained(
            self.model_repo, use_auth_token=get_token(), trust_remote_code=True
        )
        self.model.eval()

    def search_by_sequence(self, sequence: str, n: int, organism: Optional[str] = None):
        max_length = self.max_lengths[0]
        vec = self._embed_sequence(max_length, sequence)
        response = self.search(vec, n_results=n, is_peptide=False, organism=organism)
        search_results = self._format_search_results(response)
        return search_results

    def _embed_sequence(self, max_length, sequence):
        encoded = self.tokenizer.encode_plus(
            sequence,
            add_special_tokens=True,
            truncation=True,
            max_length=max_length,
            padding="max_length",
            return_tensors="pt",
        )
        with torch.no_grad():
            vec = (
                self.model.forward1(encoded.to(self.model.device))
                .squeeze()
                .cpu()
                .numpy()
            )
        return vec

    def _format_search_results(self, response):
        search_results = []
        max_dist = math.sqrt(2 * self.n_dims)
        for res in response:
            entry = res["entity"]
            dist = math.sqrt(res["distance"])
            entry["dist"] = dist
            entry["score"] = (max_dist - dist) / max_dist
            search_results.append(entry)
        return search_results

    def search(
        self,
        vec: List[float],
        n_results: int,
        is_peptide: bool,
        organism: Optional[str] = None,
    ):
        is_peptide = bool(is_peptide)
        filter_str = f"is_peptide == {is_peptide}"
        if organism is not None:
            filter_str += f" and organism == '{organism}'"

        results = self.client.search(
            collection_name=self.milvus_params.collection_name,
            data=[vec],
            limit=n_results,
            output_fields=[
                "genes",
                "uniprot_id",
                "pdb_name",
                "chain_id",
                "is_peptide",
                "organism",
            ],
            filter=filter_str,
        )
        return results[0]

    def get_organisms(self):
        res = self.client.query(
            collection_name=self.milvus_params.collection_name,
            output_fields=["organism"],
            filter="entry_id > 0",
        )
        return res