import os
import sys
sys.path.append(os.path.dirname(os.path.dirname(__file__)))
import tempfile
import config
import nltk

from typing import List
from nltk.corpus import words
from loguru import logger
from llm.call_llm import get_completion_from_messages
from embedding.call_embedding import get_embedding
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.document_loaders import PyMuPDFLoader
from langchain.vectorstores import Chroma

from prompts import system_message_select

WORDS_DB_PATH = "../words_db"
VECTOR_DB_PATH = "./vector_db/chroma"

def parse_file(file_path):
    docs = []
    # check file type
    file_type = file_path.split('.')[-1]
    if file_type == 'pdf':
        loader = PyMuPDFLoader(file_path)
        content = loader.load()
        docs.extend(content)
    else: 
        return "File type not supported"
    if len(docs) > 5:
        return "File too large, please select a pdf file with less than 5 pages"
    
    slices = split_text(docs)  # split content into slices 
    words = extract_words(slices)  # extract words from slices 
    try: 
        vectorize_words(words)   # store words into vector database 
    except Exception as e:
        logger.error(e)
    
    return ""

def parse_text(input: str):
    content = input
    return content

def split_text(docs: List[object]):
    """Split text into slices"""
    text_splitter = RecursiveCharacterTextSplitter(
        chunk_size = 1500,  
        chunk_overlap = 150 
    )
    splits = text_splitter.split_documents(docs)
    logger.info(f"Split {len(docs)} pages document into {len(splits)} slices")
    return splits

def extract_words(splits: List[object]):
    """Extract words from slices"""
    all_words = []
    for slice in splits:
        tmp_content = slice.page_content
        messages =  [  
            {'role':'system', 
            'content': system_message_select},    
            {'role':'user', 
            'content': f"{tmp_content}"},  
        ]
        respond = get_completion_from_messages(messages, api_key=config.api_key)
        words_list = respond.split(", ")
        if len(words_list) == 0:
            continue
        else:
            all_words.extend(words_list)
    all_words = wash_words(all_words)
    logger.info(f"Extract {len(all_words)} words from slices")
    return all_words

def wash_words(input_words: list[str]):
    """Wash words into a list of correct english words"""
    words_list = [word for word in input_words 
                      if len(word) >= 3 and len(word) <= 30]
    nltk.download('words')
    english_words = set(words.words())
    filtered_words = [word.lower() for word in words_list if word.lower() in english_words]
    filtered_words = list(set(filtered_words))
    logger.info(f"Wash {len(filtered_words)} words into a list of correct english words")
    return filtered_words

def get_words_from_text(input: str):
    words = input.split(' ')
    return words

def store_words(input: str, db_path=WORDS_DB_PATH):
    """Store words into database"""
    pass

def vectorize_words(input: list[str], embedding=None):
    """Vectorize words into vectors"""
    model = get_embedding("openai", embedding_key=config.api_key)
    persist_path = VECTOR_DB_PATH
    vectordb = Chroma.from_texts(
        texts=input,
        embedding=model,
        persist_directory=persist_path
    ) 
    vectordb.persist()
    logger.info(f"Vectorized {len(input)} words into vectors")
    return vectordb

def get_similar_k_words(query_word, k=3) -> List[str]: 
    # get 3 simlilar words from DB 
    model = get_embedding("openai", embedding_key=config.api_key)
    vectordb = Chroma(persist_directory=VECTOR_DB_PATH, embedding_function=model)
    similar_words = vectordb.max_marginal_relevance_search(query_word, k=k)
    similar_words = [word.page_content for word in similar_words]
    logger.info(f"Get {k} similar words {similar_words} from DB")
    return similar_words

def create_db(input, chat_history):
    """The input is file or text"""
    action_msg = ""  # the description of user action: put file or text into database
    # 1. for file upload
    if isinstance(input, tempfile._TemporaryFileWrapper):  
        tmp_file_path = input.name
        file_name = tmp_file_path.split('/')[-1]
        action_msg = f"Add words from my file: {file_name} to database"
        try:
            parse_file(tmp_file_path) #TODO
            output = f"Words from your file: {file_name} has been added to database"
        except Exception as e:
            logger.error(e)
            output = f"Error: failed to use your file: {file_name} generate dictionary"
    # 2. for text input
    elif isinstance(input, str):   
        action_msg = f"Add words from my text: {input} to database"
        try:
            parse_text(input)  #TODO
            output = f"Words from your text: {input} has been added to database"
        except Exception as e:
            logger.error(e)
            output = f"Error: failed to use your text: {input} generate dictionary"
    chat_history.append((action_msg, output))

    return chat_history


if __name__ == "__main__":
    create_db(embeddings="m3e")