import os
from haystack.document_store.sql import SQLDocumentStore
from haystack.document_store.memory import InMemoryDocumentStore
from haystack.document_store.elasticsearch import Elasticsearch, ElasticsearchDocumentStore
from haystack.document_store.faiss import FAISSDocumentStore
from haystack.retriever.sparse import ElasticsearchRetriever, TfidfRetriever
from haystack.retriever.dense import DensePassageRetriever
from haystack.reader.farm import FARMReader
from haystack.reader.transformers import TransformersReader
import logging
import subprocess
import time

from pathlib import Path
logger = logging.getLogger(__name__)


reader_models = ["deepset/roberta-base-squad2", "deepset/minilm-uncased-squad2", "deepset/bert-base-cased-squad2", "deepset/bert-large-uncased-whole-word-masking-squad2", "deepset/xlm-roberta-large-squad2"]
reader_types = ["farm"]
data_dir_reader = Path("../../data/squad20")
filename_reader = "dev-v2.0.json"

doc_index = "eval_document"
label_index = "label"

def get_document_store(document_store_type, es_similarity='cosine'):
    """ TODO This method is taken from test/conftest.py but maybe should be within Haystack.
    Perhaps a class method of DocStore that just takes string for type of DocStore"""
    if document_store_type == "sql":
        if os.path.exists("haystack_test.db"):
            os.remove("haystack_test.db")
        document_store = SQLDocumentStore(url="sqlite:///haystack_test.db")
    elif document_store_type == "memory":
        document_store = InMemoryDocumentStore()
    elif document_store_type == "elasticsearch":
        # make sure we start from a fresh index
        client = Elasticsearch()
        client.indices.delete(index='haystack_test*', ignore=[404])
        document_store = ElasticsearchDocumentStore(index="eval_document", similarity=es_similarity)
    elif document_store_type in("faiss_flat", "faiss_hnsw"):
        if document_store_type == "faiss_flat":
            index_type = "Flat"
        elif document_store_type == "faiss_hnsw":
            index_type = "HNSW"

        #TEMP FIX for issue with deleting docs
        # status = subprocess.run(
        #     ['docker rm -f haystack-postgres'],
        #     shell=True)
        # time.sleep(3)
        # try:
        #     document_store = FAISSDocumentStore(sql_url="postgresql://postgres:password@localhost:5432/haystack",
        #                                         faiss_index_factory_str=index_type)
        # except:
        # Launch a postgres instance & create empty DB
        # logger.info("Didn't find Postgres. Start a new instance...")
        status = subprocess.run(
            ['docker rm -f haystack-postgres'],
            shell=True)
        time.sleep(1)
        status = subprocess.run(
            ['docker run --name haystack-postgres -p 5432:5432 -e POSTGRES_PASSWORD=password -d postgres'],
            shell=True)
        time.sleep(3)
        status = subprocess.run(
            ['docker exec -it haystack-postgres psql -U postgres -c "CREATE DATABASE haystack;"'], shell=True)
        time.sleep(1)
        document_store = FAISSDocumentStore(sql_url="postgresql://postgres:password@localhost:5432/haystack",
                                            faiss_index_factory_str=index_type)

    else:
        raise Exception(f"No document store fixture for '{document_store_type}'")
    return document_store

def get_retriever(retriever_name, doc_store):
    if retriever_name == "elastic":
        return ElasticsearchRetriever(doc_store)
    if retriever_name == "tfidf":
        return TfidfRetriever(doc_store)
    if retriever_name == "dpr":
        return DensePassageRetriever(document_store=doc_store,
                                      query_embedding_model="facebook/dpr-question_encoder-single-nq-base",
                                      passage_embedding_model="facebook/dpr-ctx_encoder-single-nq-base",
                                      use_gpu=True)

def get_reader(reader_name, reader_type, max_seq_len=384):
    reader_class = None
    if reader_type == "farm":
        reader_class = FARMReader
    elif reader_type == "transformers":
        reader_class = TransformersReader
    return reader_class(reader_name, top_k_per_candidate=4, max_seq_len=max_seq_len)

def index_to_doc_store(doc_store, docs, retriever, labels=None):
    doc_store.write_documents(docs, doc_index)
    if labels:
        doc_store.write_labels(labels, index=label_index)
    # these lines are not run if the docs.embedding field is already populated with precomputed embeddings
    # See the prepare_data() fn in the retriever benchmark script
    elif callable(getattr(retriever, "embed_passages", None)) and docs[0].embedding is None:
        doc_store.update_embeddings(retriever, index=doc_index)

def load_config(config_filename, ci):
    conf = json.load(open(config_filename))
    if ci:
        params = conf["params"]["ci"]
    else:
        params = conf["params"]["full"]
    filenames = conf["filenames"]
    max_docs = max(params["n_docs_options"])
    n_docs_keys = sorted([int(x) for x in list(filenames["embeddings_filenames"])])
    for k in n_docs_keys:
        if max_docs <= k:
            filenames["embeddings_filenames"] = [filenames["embeddings_filenames"][str(k)]]
            filenames["filename_negative"] = filenames["filenames_negative"][str(k)]
            break
    return params, filenames