#!/usr/bin/env python3
"""
Vorverarbeitung von Obsidian-Markdown zu sauberem Pandoc-Markdown.

Behandelt:
  - Obsidian-Wikilinks:  [[Ziel]]  [[Ziel|Anzeige]]  [[bild.jpg|BreitePx]]
  - Emoji -> drucktaugliche Glyphen bzw. Text (dekorative Emojis werden entfernt)
  - ==Markierung==  ->  **fett** (drucktauglicher Ersatz)
  - %% Kommentare %%  ->  entfernt
  - Variation-Selektoren (U+FE0F/U+FE0E) entfernen

Aufruf:
  obsidian_preprocess.py <VAULT_ROOT> < eingabe.md > ausgabe.md
"""
import os
import re
import sys

IMG_EXT = {".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".svg", ".avif"}

# Emoji -> Ersatz (leerer String = entfernen)
EMOJI = {
    "\U0001F449": "\u2192",   # 👉  ->
    "\U0001F7E1": "\u25CF",   # 🟡  ●
    "\u26A0": "\u26A0",       # ⚠  (wird über DejaVu-Fallback gesetzt)
    "\u2600": "\u2600",       # ☀  (DejaVu-Fallback)
    "\U0001F338": "",         # 🌸
    "\U0001F342": "",         # 🍂
    "\u2744": "",             # ❄
    "\U0001F324": "",         # 🌤
    "\U0001F5FA": "",         # 🗺
    "\U0001F3D4": "",         # 🏔
    "\U0001F5E3": "",         # 🗣
    "\U0001F48E": "",         # 💎
    "\U0001F3B2": "",         # 🎲
    "\u26A1": "",             # ⚡
    "\U0001F4C8": "",         # 📈
    "\U0001F4C9": "",         # 📉
    "\U0001F504": "",         # 🔄
}
VS = {"\uFE0F", "\uFE0E"}

SKIP_DIRS = {".git", ".obsidian", ".trash", "node_modules"}


def scan_images(root: str) -> dict:
    """basename(lower) -> absoluter Pfad (nur Nicht-.trash-Pfade)."""
    mapping = {}

    def walk():
        for dirpath, dirnames, filenames in os.walk(root):
            dirnames[:] = [d for d in dirnames if d not in SKIP_DIRS]
            for fn in filenames:
                if os.path.splitext(fn)[1].lower() in IMG_EXT:
                    # Absoluter Pfad, damit Pandoc das Bild unabhängig vom
                    # aktuellen Arbeitsverzeichnis findet.
                    full = os.path.abspath(os.path.join(dirpath, fn))
                    key = fn.lower()
                    mapping.setdefault(key, full)
    walk()
    return mapping


def px_to_cm(px: float) -> float:
    return round(px / 96.0 * 2.54, 2)


def resolve_wikilink(image_map: dict, inner: str) -> str:
    if "|" in inner:
        target, disp = inner.split("|", 1)
    else:
        target, disp = inner, None
    target = target.strip()
    ext = os.path.splitext(target.lower())[1]
    if ext in IMG_EXT:
        path = image_map.get(target.lower(), target)
        alt = os.path.basename(target)
        if disp is not None and disp.strip().isdigit():
            width = px_to_cm(int(disp.strip()))
            return f"![{alt}]({path}){{width={width}cm}}"
        return f"![{alt}]({path}){{width=100%}}"
    # Notiz-Link -> Klartext
    return (disp.strip() if disp is not None else target)


def process(text: str, image_map: dict) -> str:
    # 1. Kommentare
    text = re.sub(r"%%.*?%%", "", text, flags=re.DOTALL)
    # 2. Wikilinks
    text = re.sub(r"\[\[([^\]]+)\]\]", lambda m: resolve_wikilink(image_map, m.group(1)), text)
    # 3. Variation-Selektoren
    for vs in VS:
        text = text.replace(vs, "")
    # 4. Emoji
    for k, v in EMOJI.items():
        text = text.replace(k, v)
    # 5. ==mark== -> **fett**
    text = re.sub(r"==([^=\n]+)==", r"**\1**", text)
    # 6. Leerraum glätten (nach Emoji-Entfernung), aber Tabellen/Code unberührt
    out = []
    for line in text.split("\n"):
        stripped = line.lstrip()
        if not stripped.startswith("|") and not stripped.startswith("```"):
            line = re.sub(r"[ \t]{2,}", " ", line)
        out.append(line)
    return "\n".join(out)


def main():
    root = sys.argv[1] if len(sys.argv) > 1 else "."
    image_map = scan_images(root)
    sys.stdout.write(process(sys.stdin.read(), image_map))


if __name__ == "__main__":
    main()