#!/usr/bin/env python3

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


def parse_arguments(args):
    if len(args) != 3:
        exit(f'Usage: {argv[0]} TOP-DIR OUTPUT-DIR')

    return argv[1], argv[2]


def find_sources(top_dir):
    p = run(
        ('find', top_dir, '-name', '*.md', '-o', '-name', '*.org'),
        capture_output=True, check=True, text=True
    )

    return p.stdout.splitlines()


def html_path(source_path, top_dir, out_dir):
    fname = path.basename(source_path)
    dname = path.dirname(source_path)

    name, _ = path.splitext(fname)

    if name == 'README':
        name = 'index'

    return path.join(
        out_dir, path.relpath(dname, top_dir), f'{name}.html'
    )


def write_dependencies(output, sources, top_dir, out_dir):
    pages = []

    for src in sources:
        html = html_path(src, top_dir, out_dir)
        html_dir = path.dirname(html)

        print(f'{html}: {src} | {html_dir}', file=output)

        pages.append(html)

    print(file=output)
    print(f'pages = {" ".join(pages)}', file=output)


def main(argv):
    top_dir, out_dir = parse_arguments(argv)
    source_files = find_sources(top_dir)

    with open('deps.mk', 'w') as deps:
        write_dependencies(deps, source_files, top_dir, out_dir)


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