#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
PPTX Grafik-Komprimier-Tool (nur CaesiumCLT, Multi-Thread, sauberes Cleanup)
Version: 1.0.0

Highlights:
- Caesium-Scratch außerhalb des PPTX-Arbeitsverzeichnisses -> keine Tempfiles in finaler PPTX
- Safety-Cleanup: entfernt 'caesium*' Ordner und '*.tmp' in ppt/media, bevor gezippt wird
- Overwrite Policy: -O bigger
- Log: image_name,size_before,size_after,saving,saving_percent
- Summary inkl. Zeit benötigt

Benutzung:
    python pptx_image_compress.py -i input.pptx [-o output.pptx] [-t THREADS] [--version]
"""

import argparse
import os
import sys
import zipfile
import tempfile
import shutil
import subprocess
import time
from pathlib import Path
from datetime import timedelta
from concurrent.futures import ThreadPoolExecutor, as_completed
from threading import Lock

# -------------------- Version --------------------
__version__ = "1.0.0"

# -------------------- Konfiguration --------------------
ALLOWED_EXT = {".jpg", ".jpeg", ".png", ".webp", ".gif"}  # GIF wird übersprungen
CAESIUM_QUALITY = 90  # -q 90
PROGRESS_BAR_LEN = 40
TEMP_PREFIX = "pptx_compress_"


# -------------------- Utilities --------------------
def human_mb(nbytes: int) -> float:
    return round(nbytes / (1024 * 1024), 2)


def ensure_clean_file(path: Path):
    if path.exists():
        try:
            if path.is_file():
                path.unlink()
            else:
                shutil.rmtree(path, ignore_errors=True)
        except Exception:
            pass


def cleanup_old_temps():
    tmp_root = Path(tempfile.gettempdir())
    for p in tmp_root.glob(f"{TEMP_PREFIX}*"):
        try:
            if p.is_dir():
                shutil.rmtree(p, ignore_errors=True)
            else:
                p.unlink(missing_ok=True)
        except Exception:
            pass


def print_progress(i: int, total: int):
    if total <= 0:
        return
    done = int(PROGRESS_BAR_LEN * i / total)
    bar = "█" * done + "-" * (PROGRESS_BAR_LEN - done)
    pct = int(i * 100 / total)
    print(f"\rBilder: |{bar}| {i}/{total} ({pct}%)", end="", flush=True)


def zip_dir_to_pptx(src_dir: Path, out_pptx: Path):
    with zipfile.ZipFile(out_pptx, "w", compression=zipfile.ZIP_DEFLATED) as z:
        for root, _, files in os.walk(src_dir):
            for f in files:
                full = Path(root) / f
                rel = full.relative_to(src_dir)
                z.write(full, arcname=str(rel))


def which(cmd: str) -> str | None:
    return shutil.which(cmd)


def compress_with_caesium(original: Path, out_dir: Path, caesium_threads: int | None) -> Path | None:
    """
    Ruft caesiumclt auf, um eine komprimierte Version zu erzeugen.
    Output wird ins out_dir geschrieben (gleicher Filename).
    Gibt Pfad zur erzeugten Datei zurück oder None bei Fehler.
    """
    exe = which("caesiumclt")
    if not exe:
        raise RuntimeError(
            "❌ 'caesiumclt' wurde nicht gefunden. Bitte CaesiumCLT installieren und in PATH verfügbar machen."
        )

    out_dir.mkdir(parents=True, exist_ok=True)

    # Nur Formate an Caesium geben, die es unterstützt: JPG/JPEG, PNG, WEBP
    ext = original.suffix.lower()
    if ext not in {".jpg", ".jpeg", ".png", ".webp"}:
        return None  # GIF & andere werden übersprungen

    cmd = [
        exe,
        "-q", str(CAESIUM_QUALITY),
        "-O", "bigger",        # <<< nur überschreiben, wenn Ziel größer ist
        "-o", str(out_dir),
    ]
    if caesium_threads is not None:
        cmd += ["--threads", str(caesium_threads)]
    cmd += [str(original)]

    try:
        r = subprocess.run(cmd, capture_output=True, text=True)
        if r.returncode != 0:
            sys.stderr.write(f"\n[caesiumclt] Fehler bei {original.name}:\n{r.stderr}\n")
            return None

        out_file = out_dir / original.name
        return out_file if out_file.exists() else None
    except Exception as ex:
        sys.stderr.write(f"\n[caesiumclt] Ausnahme bei {original.name}: {ex}\n")
        return None


def format_duration(seconds: float) -> str:
    total_ms = int(round(seconds * 1000))
    td = timedelta(milliseconds=total_ms)
    base = str(td)
    if "." in base:
        hms, frac = base.split(".", 1)
        return f"{hms}.{frac[:2]}"
    return base


def main():
    start_time = time.perf_counter()

    parser = argparse.ArgumentParser(
        description="PPTX Grafik-Komprimier-Tool (nur CaesiumCLT, Multi-Thread, sauberes Cleanup)",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument("-i", "--input", help="Input-PPTX", required=False)
    parser.add_argument("-o", "--output", help="Output-PPTX", required=False)
    parser.add_argument(
        "-t", "--threads",
        type=int,
        default=min(32, os.cpu_count() or 4),
        help="Anzahl paralleler Threads für die Bildverarbeitung"
    )
    parser.add_argument(
        "--version",
        action="version",
        version=f"%(prog)s {__version__}"
    )

    args = parser.parse_args()

    if not args.input:
        parser.print_help()
        sys.exit(1)

    input_pptx = Path(args.input).resolve()
    if not input_pptx.exists() or input_pptx.suffix.lower() != ".pptx":
        print("❌ Eingabedatei existiert nicht oder ist keine .pptx")
        sys.exit(2)

    if args.output:
        output_pptx = Path(args.output).resolve()
    else:
        output_pptx = input_pptx.with_name(f"{input_pptx.stem}_compressed.pptx")

    # Vorherige Temp-Files & existierendes Output löschen
    cleanup_old_temps()
    ensure_clean_file(output_pptx)

    # --- Zwei getrennte Temp-Verzeichnisse ---
    work_dir = Path(tempfile.mkdtemp(prefix=TEMP_PREFIX + "work_"))     # entpackte PPTX
    scratch_dir = Path(tempfile.mkdtemp(prefix=TEMP_PREFIX + "scratch_"))  # Caesium-Ausgaben (außerhalb!)

    # Logdatei neben Output
    log_file = output_pptx.with_suffix(".log")
    ensure_clean_file(log_file)
    log_lines = ["image_name,size_before,size_after,saving,saving_percent\n"]

    size_before = input_pptx.stat().st_size

    try:
        # Entpacken
        with zipfile.ZipFile(input_pptx, "r") as z:
            z.extractall(work_dir)

        media_dir = work_dir / "ppt" / "media"
        images = []
        if media_dir.exists():
            for f in sorted(media_dir.iterdir()):
                if f.is_file() and f.suffix.lower() in ALLOWED_EXT:
                    images.append(f)

        total = len(images)
        print(f"🔧 Finde Bilder in {media_dir} ... {total} Kandidaten")
        print_progress(0, total)

        # Vorab prüfen, ob caesiumclt verfügbar ist
        if not which("caesiumclt"):
            print("\n❌ 'caesiumclt' nicht gefunden. Bitte installieren und in PATH verfügbar machen.")
            sys.exit(3)

        # Oversubscription vermeiden: viele Python-Threads -> caesium intern 1 Thread
        caesium_threads = 1 if args.threads and args.threads > 1 else None

        # Thread-sichere Fortschritts- & Log-Verwaltung
        lock = Lock()
        done_count = 0

        def worker(idx: int, img_path: Path):
            nonlocal done_count
            ext = img_path.suffix.lower()
            orig_size = img_path.stat().st_size

            # GIF überspringen
            if ext == ".gif":
                with lock:
                    done_count += 1
                    log_lines.append(f"{img_path.name},{orig_size},{orig_size},0,0.0\n")
                    print_progress(done_count, total)
                return

            chosen_size = orig_size
            try:
                # Eigener Output-Unterordner pro Bild, um Kollisionen zu vermeiden
                out_sub = scratch_dir / f"img_{idx:06d}"
                caesium_out = compress_with_caesium(img_path, out_sub, caesium_threads)

                if caesium_out and caesium_out.exists():
                    s = caesium_out.stat().st_size
                    if s < orig_size:
                        # kleineren ersetzen (atomar)
                        tmp_target = img_path.with_suffix(img_path.suffix + ".tmp")
                        shutil.copy2(caesium_out, tmp_target)
                        tmp_target.replace(img_path)
                        chosen_size = s

            except Exception:
                chosen_size = orig_size  # Original beibehalten

            finally:
                saving = orig_size - chosen_size
                saving_percent = round((saving / orig_size) * 100, 2) if orig_size > 0 else 0.0
                with lock:
                    log_lines.append(f"{img_path.name},{orig_size},{chosen_size},{saving},{saving_percent}\n")
                    done_count += 1
                    print_progress(done_count, total)

        # Parallel ausführen
        if total > 0:
            with ThreadPoolExecutor(max_workers=max(1, args.threads)) as ex:
                futures = [ex.submit(worker, i, p) for i, p in enumerate(images, start=1)]
                for _ in as_completed(futures):
                    pass  # Fortschritt wird im Worker gezeichnet

        print()  # newline nach Progressbar

        # --- Safety-Cleanup innerhalb des Arbeitsverzeichnisses ---
        # 1) Entferne evtl. vorhandene caesium*-Ordner (aus alten Runs)
        for p in work_dir.rglob("*"):
            try:
                if p.is_dir() and p.name.lower().startswith("caesium"):
                    shutil.rmtree(p, ignore_errors=True)
            except Exception:
                pass

        # 2) Lösche eventuelle .tmp-Dateien in ppt/media
        media_dir = work_dir / "ppt" / "media"
        if media_dir.exists():
            for f in media_dir.iterdir():
                if f.is_file() and f.suffix.lower() == ".tmp":
                    try:
                        f.unlink(missing_ok=True)
                    except Exception:
                        pass

        # Neue PPTX bauen (nur work_dir -> scratch_dir liegt außerhalb und ist damit sicher ausgeschlossen)
        zip_dir_to_pptx(work_dir, output_pptx)
        size_after = output_pptx.stat().st_size

        # Log schreiben
        try:
            with open(log_file, "w", encoding="utf-8") as f:
                f.writelines(log_lines)
        except Exception:
            pass
        # Summary
        savings_pct = 0.0
        if size_before > 0:
            savings_pct = round(100.0 * (size_before - size_after) / size_before, 2)

        elapsed = time.perf_counter() - start_time

        print("\n✅ Fertig!")
        print("Summary")
        print("-------")
        print(f"Version:              {__version__}")
        print(f"Name:                 {output_pptx.name}")
        print(f"Datei-Größe vorher:   {human_mb(size_before)} MB")
        print(f"Datei-Größe nachher:  {human_mb(size_after)} MB")
        print(f"Ersparnis:            {savings_pct}%")
        print(f"Zeit benötigt:        {format_duration(elapsed)}")
        print(f"Log-Datei:            {log_file}")

    finally:
        # Aufräumen ALLER temporären Dateien/Ordner
        try:
            shutil.rmtree(work_dir, ignore_errors=True)
        except Exception:
            pass
        try:
            shutil.rmtree(scratch_dir, ignore_errors=True)
        except Exception:
            pass
        # Zusätzlich: ältere Reste entfernen
        cleanup_old_temps()


if __name__ == "__main__":
    main()