import csv
import re


def load_lines(filename):
    lines = []
    with open(filename) as f:
        for line in f:
            lines.append(line.strip())
    return lines


def remove_titles_and_bad_tracks(lines):
    is_track = re.compile(r"^\d.*")
    better_lines = []
    for line in lines:
        if is_track.match(line) and "???" not in line:
            better_lines.append(line)
    return better_lines


def group_by_set(lines):
    is_set_title = re.compile(r".*:$")
    is_track = re.compile(r"^\d.*:")
    grouped_lines = []

    current_set = []
    for line in lines:
        if not line.strip():
            continue
        if is_set_title.match(line) and len(current_set) > 0:
            grouped_lines.append(current_set)
            current_set = []
        elif is_track.match(line) and "???" not in line:
            current_set.append(line)

    return grouped_lines


def get_grouped_artists(grouped_lines):
    artist_from_track = re.compile(r"\d+\: (.+?) - .+?")
    artist_names = []
    for dj_set_lines in grouped_lines:
        dj_set_artists = []
        for line in dj_set_lines:
            if artist_match := artist_from_track.match(line):
                artist_name = artist_match.group(1).strip().lower()
                dj_set_artists.append(artist_name)
        artist_names.append(dj_set_artists)

    return artist_names


def write_to_csv(filename):
    with open(output_filename, "w", newline="") as csvfile:
        writer = csv.writer(csvfile)
        for artists in artist_names:
            writer.writerow(artists)


if __name__ == "__main__":
    filename = "data/radio-original.txt"
    output_filename = "data/artist-names-per-row.csv"

    lines = load_lines(filename)
    grouped_lines = group_by_set(lines)
    artist_names = get_grouped_artists(grouped_lines)
    write_to_csv(output_filename)