import json
import os

import nltk
from nltk import WordNetLemmatizer

from src.preprocessing.word_prunner import WordPrunner


def preprocess_folder(input_folder_path: str, output_persistence_path):
    documents = get_documents(input_folder_path)

    with open(output_persistence_path, 'w') as file:
        json.dump(documents, file)


def get_documents(input_folder_path: str) -> dict:
    preprocessor = Preprocessor()
    documents = {}
    for file in os.listdir(input_folder_path):
        if file.endswith(".txt"):
            path, words = preprocessor.read_file(input_folder_path + file)
            documents[path] = words

    return documents


def load_documents(path: str):
    with open(path, 'r') as file:
        return json.load(file)


class Preprocessor:
    def __init__(self):
        self.words = {}
        self.lemmatiser = WordNetLemmatizer()
        self.prunner = WordPrunner()

    def read_file(self, path: str) -> (str, dict):
        self.words = {}
        with open(path, 'r') as file:
            line = " "
            while line:
                line = file.readline()
                tokens = self.prunner.prune(nltk.word_tokenize(line))
                for word in tokens:
                    self.add_word(word)
        return path, self.words

    def add_word(self, term: str):
        # change case to lower
        word = self.lemmatiser.lemmatize(term)
        # add to words
        if word not in self.words:
            self.words[word] = 0
        self.words[word] += 1