import os
import sys
import re

dir = sys.argv[1]
current_file = sys.argv[2]


def add_to_tree(tree: list, path: str, vals: list) -> bool:
    root = tree[0]
    if root not in path:
        return False
    else:
        subtrees = [ child for child in tree[1] if type(child) == list ]
        for subtree in subtrees:
            if add_to_tree(subtree, path, vals):
                return True

        tree[1] += [[path, vals]]
        return True

def gen_nav_tree(tree: list) -> str:
    nav_entries = []
    for entry in tree[1]:
        if type(entry) == str:
            nav_entries += [entry]
        else:
            nav_entries += [f'<dd>{gen_nav_tree(entry)}</dd>']

    return f'<dl class="collapsable"><dt>{tree[0]}</dt>{"".join(nav_entries)}</dl>'

tree = []

for root, dirs, files in os.walk(dir):
    rel_root = os.path.relpath(root, dir)
    entries = []
    for name in files:
        if not name.endswith(".md"):
            continue

        html_name = re.sub(r"\.md$", ".html", name)
        full_path = os.path.join(rel_root, html_name)
        nav_entry = ''

        if full_path in current_file:
            nav_entry = f'<dd><a href="/{full_path}" class="on-this-page">{html_name}</a></dd>'
        else:
            nav_entry = f'<dd><a href="/{full_path}">{html_name}</a></dd>'
        entries += [nav_entry]

    if not entries:
        continue

    if not tree:
        tree = [rel_root, entries]
    else:
        add_to_tree(tree, rel_root, entries)

nav_tree = gen_nav_tree(tree)
nav_bar = f'<nav id="nav-bar"><div id="nav-bar-toggle">☰</div>{nav_tree}</nav>'

print(nav_bar)