from collections import Counter
import csv
from typing import List
import travel_resolver.libs.nlp.langage_detection.variables as var


def extract_data_from_csv(f_in: str, f_out: str):
    """
    Take a csv file containing strings and convert it
    into a csv file containig letter frequencies infos.

    Args:
        f_in (str): File path to analyse, must contain extension.
        f_out (str): File path containing result, must contain extension.
    """

    with open(f_in, "r") as csv_file:
        csv_reader = csv.reader(csv_file)

        with open(f_out, "w", newline="") as output_csv:
            csv_writer = csv.writer(output_csv)

            for row in csv_reader:
                str = "".join(row).lower()
                modified_row = extract_data_from_string(str)
                csv_writer.writerow(modified_row)


def extract_data_from_string(str_in: str) -> List:
    """
    Retreive tab containing letter frequency informations
    and special char frequency of a given string.

    Args:
        str_in (str): String to analyse.

    Returns:
        (List): Tab containing special char and alphabetical frequencies.
    """
    str_data = []
    str_data = str_data + frequence_letters(str_in)
    str_data = str_data + frequence_char_part(str_in)
    return str_data


def frequence_letters(str_in: str) -> List:
    """
    Retreive tab containing letter frequency informations
    of a given string.

    Args:
        str_in (str): String to analyse.

    Returns:
        (List): Tab containing alphabetical char frequencies.
    """
    counter = Counter(str_in.lower())
    freq_tab = [
        round(counter.get(chr(i), 0) / len(counter) * 100, 2) for i in range(97, 123)
    ]
    return freq_tab


def frequence_char_part(str_in: str) -> List:
    """
    Retreive tab containing special char frequency
    informations of a given string.

    Args:
        str_in (str): String to analyse.

    Returns:
        (List): Tab containing special char char frequencies.
    """

    counter = Counter(str_in.lower())
    freq_tab = [
        round(counter.get(char, 0) / len(str_in) * 100, 2) for char in var.SPECIAL_CHARS
    ]
    return freq_tab


def main():
    for lang in var.TRAD_TARGETS:
        input_file = "../../assets/data/prompts/csv/" + lang + "_prompts.csv"
        output_csv_file = "../../assets/data/trainset/" + lang + "_trainset.csv"
        extract_data_from_csv(input_file, output_csv_file)


if __name__ == "__main__":
    main()