#!/usr/bin/env python3

from os import path
from subprocess import run
from sys import argv, exit

from git import Repo

from helpers import compute_directories


def parse_arguments(args):
    if len(args) != 4:
        exit(f'Usage: {argv[0]} EXTENSIONS FOLDER OUTPUT-DIR')

    return argv[1].split(), argv[2], argv[3]


def list_files(extensions, folder):
    directories = compute_directories(
        extensions, Repo(search_parent_directories=True)
    )
    return directories[folder].subfolders, directories[folder].files


def generate_index_page(title, directories, files):
    lines = (f'% {title}',) + tuple(
        f'- [{d}/]({d}/index.html)' for d in directories
    ) + tuple(
        f'- [{f}]({f}.html)' for f in files
    )
    mdown = '\n'.join(lines)

    return run(
        ('pandoc', '-s'), text=True, check=True, capture_output=True,
        input=mdown
    ).stdout


def main(arguments):
    extensions, folder, out_dir = parse_arguments(arguments)

    title = path.basename(folder) if folder else 'index'

    folders, files = list_files(extensions, folder)

    parsed_filenames = (path.splitext(f) for f in files)
    names = tuple(name for name, _ in parsed_filenames)

    with open(path.join(out_dir, folder, 'index.html'), 'w') as index:
        index.write(generate_index_page(title, folders, names))


if __name__ == '__main__':
    main(argv)