#!/usr/bin/python3

"""Script for changing timelines of out-of-sync subtitles."""

import argparse
from typing import List, Tuple


def main():
    """Create a new file with update timeline, given the offset in seconds."""

    parser = argparse.ArgumentParser()
    parser.add_argument('file', help='file containing the subtitles to update')
    parser.add_argument(
        'offset', help='number of seconds to update the file with'
    )
    args = parser.parse_args()
    file = args.file
    offset = int(args.offset)

    output: List[str] = []

    with open(file, 'r') as subtitles:
        for line in subtitles.readlines():
            if '-->' in line:
                start: str = line.split(' --> ')[0]
                new_start: str = get_new_timeline(start, offset)

                end: str = line.split(' --> ')[1]
                new_end: str = get_new_timeline(end, offset)

                new_line: str = "{} --> {}".format(new_start, new_end)
                output.append(new_line)

            else:
                output.append(line)

    new_file = "UPDATED.{}".format(file)

    with open(new_file, 'w') as newfile:
        newfile.write(''.join(output))


def convert_time_to_total_seconds(hrs: int, mns: int, scs: int) -> int:
    """Take hours, minutes, seconds, Return total seconds."""

    minutes: int = hrs * 60 + mns
    seconds: int = minutes * 60 + scs

    return seconds


def convert_time_to_h_m_s(seconds: int) -> Tuple[int, int, int]:
    """Take total seconds, Return hours, minutes, seconds."""

    minutes: int = seconds // 60
    hours = minutes // 60
    minutes %= 60
    seconds %= 60

    return hours, minutes, seconds


def get_new_timeline(string: str, offset: int) -> str:
    """Convert timeline."""

    hours: str = string.split(':')[0]
    minutes: str = string.split(':')[1]
    seconds: str = string.split(':')[2].split(',')[0]
    milliseconds: str = string.split(',')[1]

    temp_seconds = convert_time_to_total_seconds(
        int(hours), int(minutes), int(seconds)
    )
    temp_seconds += offset
    new_hours, new_minutes, new_seconds = convert_time_to_h_m_s(temp_seconds)
    new_h = "{0:02d}".format(new_hours)
    new_m = "{0:02d}".format(new_minutes)
    new_s = "{0:02d}".format(new_seconds)

    new_string: str = "{}:{}:{},{}".format(
        new_h,
        new_m,
        new_s,
        milliseconds
    )

    return new_string


if __name__ == '__main__':
    main()