import os
import sys
import boto3
import botocore
import re
import pandas as pd
from nltk.corpus import stopwords
import warnings

warnings.filterwarnings("ignore")

from app.logger import Logger

sys.path.insert(0, os.path.abspath("."))


def read_files(
    file_name, sort_by=None, drop_duplicates=None, drop_na=None, encoding=None
):
    df = pd.read_csv(
        os.path.join("app/constants", file_name), low_memory=False, encoding=encoding
    )
    if sort_by:
        df = df.sort_values(by=[sort_by])
    if drop_duplicates:
        print("Removing duplicates in ProdName..")
        print("df rows before removing duplicates = " + str(df.shape[0]))
        df.drop_duplicates(subset=drop_duplicates, keep="first", inplace=True)
        print("df rows after removing duplicates = " + str(df.shape[0]))
    if drop_na:
        print("Removing rows with null values..")
        print("df rows before removing nan values = " + str(df.shape[0]))
        df = df.dropna(subset=drop_na)
        print("df rows after removing nan values = " + str(df.shape[0]))
    df = df.reset_index(drop=True)
    return df


def check_file_already_downloaded(file_name):
    files = os.listdir("app/constants")
    if file_name in files:
        return True
    return False


def download_file_from_s3(
    file_name, bucket_name="sku-matching-ai-ml", skip_check=False, file_path=None
):
    if check_file_already_downloaded(file_name) and not skip_check:
        return file_name
    else:
        print("STARTING DOWNLOADING: ", file_name)
        if not file_path:
            file_path = file_name
        s3 = boto3.client("s3")
        try:
            s3.download_file(
                Bucket=bucket_name, Key=file_path, Filename=f"app/constants/{file_name}"
            )
            print("DOWNLOADING FINISHED")
            return file_name
        # pylint: disable=invalid-name
        except botocore.exceptions.ClientError as e:
            Logger().exception(
                message=f"Unable to download file: {file_name}",
            )
            return e


def upload_files_to_s3(file_path, upload_path, bucket_name="sku-matching-ai-ml"):
    print("STARTING UPLOADING")
    s3 = boto3.client("s3")
    try:
        s3.upload_file(file_path, bucket_name, upload_path)
    except botocore.exceptions.ClientError as e:
        Logger().exception(
            message=f"Unable to uplaod file",
        )
        return e


def clean(string):
    raw_text = re.sub("[^a-zA-Z]+", " ", string)
    words = raw_text.lower().split()
    stops = set(stopwords.words("english"))
    meaningful_words = [
        word for word in words if ((not word in stops) and (len(word) >= 3))
    ]
    string = " ".join(meaningful_words)
    return string


def close_open_brackets(input_str):
    opening_brackets = ["(", "[", "{"]
    closing_brackets = [")", "]", "}"]
    stack = []

    for char in input_str:
        if char in opening_brackets:
            stack.append(char)
        elif char in closing_brackets:
            if len(stack) > 0:
                opening_bracket = stack.pop()
                if opening_brackets.index(opening_bracket) != closing_brackets.index(
                    char
                ):
                    stack.append(opening_bracket)
                    stack.append(char)
            else:
                input_str = input_str.replace(char, "")

    while len(stack) > 0:
        opening_bracket = stack.pop()
        closing_bracket = closing_brackets[opening_brackets.index(opening_bracket)]
        input_str += closing_bracket

    return input_str


def iterative_filtering(
    df,
    product,
    column_name,
    skip_clean=False,
    consider_starts_with=True,
    regex=False,
    close_brackets=False,
):
    if not skip_clean:
        product = clean(product)
    else:
        product = product.lower()
    words = product.split()
    new_df = df
    index = 0
    out_df = new_df

    while new_df.shape[0] > 0 and index < len(words):
        out_df = new_df
        new_df = df_filtering_by_word(
            new_df,
            words[index],
            column_name,
            consider_starts_with,
            regex,
            close_brackets,
        )
        if new_df.shape[0] > 0:
            out_df = new_df
        new_df[column_name] = new_df[column_name].str.replace(words[index] + " ", "")
        index = index + 1
    out_df = out_df.reset_index(drop=True)
    return out_df


def df_filtering_by_word(
    df, word, column_name, consider_starts_with=True, regex=False, close_brackets=False
):
    try:
        if close_brackets:
            word = close_open_brackets(word)

        if consider_starts_with:
            filtered_df = df[df[column_name].str.startswith(word)]
            if filtered_df.shape[0] == 0:
                filtered_df = df[df[column_name].str.contains(word)]
        else:
            if regex:
                filtered_df = df[
                    df[column_name].str.contains(rf"\b({word})\b", case=False)
                ]
            else:
                filtered_df = df[df[column_name].str.contains(word)]
        if filtered_df.shape[0] == 0:
            filtered_df = df

        return filtered_df
    except Exception as e:
        return df_filtering_by_word(df, clean(word), consider_starts_with, regex)


def remove_files(file_name):
    if os.path.exists(f"app/constants/{file_name}"):
        os.remove(f"app/constants/{file_name}")

def get_top_mrf_product(mrf_product_attributes_list, dp_product_attributes, sequence_scores, default_attr_key_list):
    scores = []
    for id, each_mrf_prod_attr in enumerate(mrf_product_attributes_list):
        score = sequence_scores[id]
        for key in default_attr_key_list:
            if key in dp_product_attributes and key in each_mrf_prod_attr:
                if pd.notna(dp_product_attributes[key]) and pd.notna(each_mrf_prod_attr[key]):
                    if str(dp_product_attributes[key]).lower() == str(each_mrf_prod_attr[key]).lower():
                        score += 5
        scores.append(score)
    
    max_index = scores.index(max(scores))
    return max_index, max(scores)

# Helper files required for FSA V2
# Preprocessing Function
'''
This Function is using for preprocessing the input product names
'''
def preprocess(text):
    text = re.sub(r'&', 'and', text)
    text = re.sub(r'[^\w\s]',' ', text)
    text = re.sub(' +', ' ', text)
    return text.strip().lower()

# Function to preprocess labels from the previous prediction
def label_processing(label):
    label = re.sub('__label__', '', label)
    label = re.sub('_', ' ', label)
    label = re.sub(' +', ' ', label)
    return label.strip().lower()

def get_return_labels(label,accuracy,threshold):
    if accuracy >= threshold:
        return_label = label
        return_score = accuracy
        label_status = f"Classified - Above threshold {threshold}"
    else:
        return_label = None
        return_score = None
        label_status = f"Unclassfied - Below threshold {threshold}"
    return return_label,return_score,label_status

#Function to get the product label and accuracy
def get_label_and_accuracy(model,product_name):
    prediction = model.predict(product_name)
    label = prediction[0][0]
    label = label_processing(label)
    accuracy = round(prediction[1][0],3)

    return label,accuracy

# Function for remove new line in product name
'''
Some products may contain new line characters in middle of product names.
This may occur because of preprocessing. It can lead to result \n in middle of the
product names.
'''
def remove_new_lines(text):
    text = re.sub('\n', ' ', text)
    return text.strip().lower()