#!/usr/bin/env python3
import re
import sys
from pathlib import Path

if len(sys.argv) != 3:
    raise SystemExit(f"Aufruf: {sys.argv[0]} EINGABE.md AUSGABE_ORDNER")

src = Path(sys.argv[1])
outdir = Path(sys.argv[2])
outdir.mkdir(parents=True, exist_ok=True)

text = src.read_text(encoding="utf-8")
parts = re.split(r"(?m)^(?=#\s+)", text)

def slugify(title: str) -> str:
    title = title.lower()
    title = re.sub(r"[^\w\s-]", "", title, flags=re.UNICODE)
    title = re.sub(r"[\s_-]+", "-", title).strip("-")
    return title[:80] or "kapitel"

index = []
chapter_no = 0

for part in parts:
    if not part.strip():
        continue

    m = re.match(r"^#\s+(.+?)\s*$", part, re.M)
    if m:
        chapter_no += 1
        title = m.group(1).strip()
        filename = f"{chapter_no:03d}-{slugify(title)}.md"
    else:
        filename = "000-vorspann.md"
        title = "Vorspann"

    (outdir / filename).write_text(part.rstrip() + "\n", encoding="utf-8")
    index.append(f"- [{title}]({filename})")

(outdir / "README.md").write_text(
    "# Inhaltsverzeichnis\n\n" + "\n".join(index) + "\n",
    encoding="utf-8",
)