import pathlib
import re


def parse_list(string):
    assert string.startswith("[")
    depth = 1
    parts = []
    part_start = i = 1
    while depth > 0:
        if depth == 1 and string[i:].startswith(','):
            parts.append(string[part_start:i].strip())
            part_start = i+1
        depth += string[i] == '['
        depth -= string[i] == ']'
        i += 1
    if string[part_start:i-1].strip():
        parts.append(string[part_start:i-1].strip())
    assert parts, string[:100]
    assert "" not in parts
    return (parts, i)


assert parse_list("[x] bruh") == (["x"], 3)
assert parse_list("[x, y[z]] bruh") == (["x", "y[z]"], 9)

for path in list(pathlib.Path("stdlib").rglob("*.pyi")) + list(pathlib.Path("stubs").rglob("*.pyi")):
    if "@python2" in path.parts:
        # no real reason to skip, I just don't like python 2
        continue

    print(path)
    content = path.read_text()

    while True:
        try:
            match = next(
                m
                for m in re.finditer(r"^.*(Union|Optional)\[", content, flags=re.MULTILINE)
                if not re.match("[A-Za-z_][A-Za-z0-9_]* = ", m.group(0).lstrip(" "))  # skip type aliases
                and not content[m.end():].startswith("]")
            )
        except StopIteration:
            break

        parts, list_length = parse_list(content[match.end()-1:])
        start = match.start(1)
        end = match.end() - 1 + list_length
        if match.group(1) == "Union":
            content = content[:start] + " | ".join(parts) + content[end:]
        else:
            [p] = parts
            content = content[:start] + f"{p} | None" + content[end:]

    path.write_text(content)

import pathlib
import re


for path in list(pathlib.Path("stdlib").rglob("*.pyi")) + list(pathlib.Path("stubs").rglob("*.pyi")):
    if "@python2" in path.parts:
        # no real reason to skip, I just don't like python 2
        continue

    print(path)
    content = path.read_text()

    for old in ["Union", "Optional"]:
        if old + "[" not in content:
            content = re.sub(rf", \b{old}\b", "", content)
            content = re.sub(rf"\b{old}\b,", "", content)
            content = content.replace(r"from typing import " + old + "\n", "")
    path.write_text(content)