#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
PPTX Grafik-Komprimier-Tool (nur CaesiumCLT, Multi-Thread, Batch, sauberes Cleanup)
Version: 1.1.6


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

Änderungen in 1.1.6:
- Libcaesium 1.3.0 kann nun auch files ignorieren, wenn die Kompression kleiner als <MIN_SAVING> ist
"""

import argparse
import os
import re
import xml.etree.ElementTree as ET
import sys
import zipfile
import tempfile
import shutil
import subprocess
import time
import fnmatch
from glob import glob
from pathlib import Path
from datetime import timedelta
from concurrent.futures import ThreadPoolExecutor, as_completed
from threading import Lock
from dataclasses import dataclass
from typing import Callable, List, Optional


__version__ = "1.1.6"

ALLOWED_EXT = {".jpg", ".jpeg", ".png", ".webp", ".gif"}
PROGRESS_BAR_LEN = 40
TEMP_PREFIX = "pptx_compress_"
DEFAULT_MIN_SAVINGS = "2%"


@dataclass
class DeckResult:
    input: str
    output: str
    ok: bool = False
    size_before: int = 0
    size_after: int = 0
    elapsed_sec: float = 0.0
    error: Optional[str] = None
    log_file: Optional[str] = None


@dataclass
class ImageProcessResult:
    image_name: str
    orig_size: int
    chosen_size: int
    slide_nr: str


def discover_images(media_dir: Path) -> list[Path]:
    images: list[Path] = []
    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)
    return images


def image_result_to_log_line(image_result: ImageProcessResult) -> str:
    saving = image_result.orig_size - image_result.chosen_size
    saving_percent = round((saving / image_result.orig_size) * 100, 2) if image_result.orig_size > 0 else 0.0
    return f"{image_result.image_name};{human_kb(image_result.orig_size)};{human_kb(image_result.chosen_size)};{human_kb(saving)};{saving_percent};{image_result.slide_nr}\n"


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

def human_kb(nbytes: int) -> float:
    return round(nbytes / 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):
    return shutil.which(cmd)

def compress_with_caesium(original: Path, out_dir: Path, caesium_threads: int | None, quality: int, min_savings: str) -> Path | None:
    exe = which("caesiumclt")
    if not exe:
        raise RuntimeError("[ERROR] 'caesiumclt' wurde nicht gefunden. Bitte CaesiumCLT installieren und in PATH verfügbar machen.")
    out_dir.mkdir(parents=True, exist_ok=True)
    ext = original.suffix.lower()
    if ext not in {".jpg", ".jpeg", ".png", ".webp", ".gif"}:
        return None
    cmd = [exe, "-q", str(quality), "-O", "bigger", "--min-savings", min_savings, "-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"[caesiumclt] Fehler bei {original.name}:{r.stderr}")
            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"[caesiumclt] Ausnahme bei {original.name}: {ex}")
        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 build_image_slide_index(rels_dir: Path) -> dict[str, List[int]]:
    if not rels_dir.exists() or not rels_dir.is_dir():
        return {}

    image_to_slides: dict[str, set[int]] = {}

    for rels_path in rels_dir.iterdir():
        rels_file = rels_path.name
        if rels_file.startswith("slide") and rels_file.endswith(".xml.rels") and rels_path.is_file():
            match = re.search(r"slide(\d+)\.xml\.rels$", rels_file)
            if not match:
                continue
            slide_number = int(match.group(1))
            try:
                tree = ET.parse(rels_path)
                root = tree.getroot()
                for rel in root.findall(".//{http://schemas.openxmlformats.org/package/2006/relationships}Relationship"):
                    target = rel.attrib.get("Target", "")
                    image_name = Path(target).name
                    if image_name:
                        if image_name not in image_to_slides:
                            image_to_slides[image_name] = set()
                        image_to_slides[image_name].add(slide_number)
            except (ET.ParseError, OSError):
                print(f"Fehler beim Lesen von {rels_file}")

    return {img: sorted(slides) for img, slides in image_to_slides.items()}


def get_slide_numbers_for_image(rels_dir: Path, image_filename: str) -> Optional[List[int]]:
    image_to_slides = build_image_slide_index(rels_dir)
    slides = image_to_slides.get(image_filename)
    return slides if slides else None


def process_image_file(
    idx: int,
    img_path: Path,
    scratch_dir: Path,
    image_to_slides: dict[str, List[int]],
    caesium_threads: int | None,
    quality: int,
    min_savings: str,
    compressor: Callable[[Path, Path, int | None, int, str], Path | None],
) -> ImageProcessResult:
    orig_size = img_path.stat().st_size
    chosen_size = orig_size
    found_in_slide = image_to_slides.get(img_path.name)
    slide_nr = "NOT_USED" if found_in_slide is None else str(found_in_slide)

    try:
        out_sub = scratch_dir / f"img_{idx:06d}"
        caesium_out = compressor(img_path, out_sub, caesium_threads, quality, min_savings)
        if caesium_out and caesium_out.exists():
            s = caesium_out.stat().st_size
            if s < orig_size:
                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

    return ImageProcessResult(
        image_name=img_path.name,
        orig_size=orig_size,
        chosen_size=chosen_size,
        slide_nr=slide_nr,
    )


# -------------------- Core per-deck processing --------------------
def process_single_deck(
    input_pptx: Path,
    output_pptx: Path,
    threads: int,
    quality: int,
    min_savings: str,
    compressor: Callable[[Path, Path, int | None, int, str], Path | None] = compress_with_caesium,
) -> DeckResult:
    start_time = time.perf_counter()
    result = DeckResult(
        input=str(input_pptx),
        output=str(output_pptx),
    )

    try:
        if not input_pptx.exists() or input_pptx.suffix.lower() != ".pptx":
            raise ValueError("Eingabedatei existiert nicht oder ist keine .pptx")

        cleanup_old_temps()
        ensure_clean_file(output_pptx)

        work_dir = Path(tempfile.mkdtemp(prefix=TEMP_PREFIX + "work_"))
        scratch_dir = Path(tempfile.mkdtemp(prefix=TEMP_PREFIX + "scratch_"))

        log_file = output_pptx.with_suffix(".log.csv")
        ensure_clean_file(log_file)
        log_lines = ["image_name;size_before(kb);size_after(kb);saving(kb);saving_percent(%);in_slide_number\n"]

        size_before = input_pptx.stat().st_size
        result.size_before = size_before

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

        slides_dir  = work_dir / "ppt" / "slides"
        rels_dir = slides_dir / "_rels"
        media_dir = work_dir / "ppt" / "media"

        images = discover_images(media_dir)

        total = len(images)
        print(f"[Processing] {input_pptx.name}: {total} Bild(er) gefunden")
        print_progress(0, total)

        if not which("caesiumclt") and compressor is compress_with_caesium:
            raise RuntimeError("'caesiumclt' nicht gefunden. Bitte installieren und in PATH verfügbar machen.")

        caesium_threads = 1 if threads and threads > 1 else None
        lock = Lock()
        done_count = 0
        image_to_slides = build_image_slide_index(rels_dir)

        def worker(idx: int, img_path: Path):
            nonlocal done_count
            image_result = process_image_file(
                idx=idx,
                img_path=img_path,
                scratch_dir=scratch_dir,
                image_to_slides=image_to_slides,
                caesium_threads=caesium_threads,
                quality=quality,
                min_savings=min_savings,
                compressor=compressor,
            )

            with lock:
                log_lines.append(image_result_to_log_line(image_result))
                done_count += 1
                print_progress(done_count, total)

        if total > 0:
            with ThreadPoolExecutor(max_workers=max(1, threads)) as ex:
                futures = [ex.submit(worker, i, p) for i, p in enumerate(images, start=1)]
                for _ in as_completed(futures):
                    pass

        print()  # newline

        # Safety cleanup inside work_dir
        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

        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

        zip_dir_to_pptx(work_dir, output_pptx)
        size_after = output_pptx.stat().st_size
        result.size_after = size_after

        try:
            with open(log_file, "w", encoding="utf-8") as f:
                f.writelines(log_lines)
        except Exception:
            pass

        elapsed = time.perf_counter() - start_time
        result.elapsed_sec = elapsed
        result.log_file = str(log_file)
        result.ok = True

        savings_pct = 0.0 if size_before == 0 else round(100.0 * (size_before - size_after) / size_before, 2)
        print(f"[OK] Fertig!  ({input_pptx.name})")
        print("Zusammenfassung ----------------")
        print("  Vorher:    ", human_mb(size_before), "MB")
        print("  Nachher:   ", human_mb(size_after), "MB")
        print("  Ersparnis: ", f"{savings_pct}%")
        print("  Zeit:      ", format_duration(elapsed))
        print("  Log:       ", log_file)

    except Exception as e:
        result.error = str(e)
    finally:
        try:
            shutil.rmtree(work_dir, ignore_errors=True)  # type: ignore[name-defined]
        except Exception:
            pass
        try:
            shutil.rmtree(scratch_dir, ignore_errors=True)  # type: ignore[name-defined]
        except Exception:
            pass
        cleanup_old_temps()

    return result

# -------------------- Input helpers --------------------
def expand_inputs(inputs: list[str]) -> list[Path]:
    files: list[Path] = []
    for inp in inputs:
        p = Path(inp)
        if any(ch in inp for ch in ['*', '?']):
            for g in glob(inp):
                if g.lower().endswith('.pptx'):
                    files.append(Path(g).resolve())
        else:
            if p.is_dir():
                for g in p.glob('*.pptx'):
                    files.append(g.resolve())
            else:
                if p.suffix.lower() == '.pptx':
                    files.append(p.resolve())
    seen = set()
    uniq = []
    for f in files:
        if str(f) not in seen:
            uniq.append(f)
            seen.add(str(f))
    return uniq


def collect_from_dir(input_dir: Path, pattern: str, recursive: bool) -> list[Path]:
    files: list[Path] = []
    if recursive:
        for root, _, names in os.walk(input_dir):
            for n in names:
                if fnmatch.fnmatch(n, pattern):
                    p = Path(root) / n
                    if p.suffix.lower() == '.pptx':
                        files.append(p.resolve())
    else:
        for p in input_dir.glob(pattern):
            if p.suffix.lower() == '.pptx':
                files.append(p.resolve())
    seen = set()
    out = []
    for f in files:
        s = str(f)
        if s not in seen:
            out.append(f)
            seen.add(s)
    return out

# -------------------- CLI --------------------
def main():
    parser = argparse.ArgumentParser(
        description="PPTX Grafik-Komprimier-Tool (nur CaesiumCLT, Multi-Thread, Batch, sauberes Cleanup)",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument('-i','--input', nargs='*', help='Input-PPTX (eine oder mehrere, Wildcards erlaubt). Bei mehreren: -O erforderlich.')
    parser.add_argument('--input-dir', help='Eingabe-Verzeichnis (optional, für Batch)')
    parser.add_argument('-o','--output', help='Output-PPTX (nur Single-Mode)')
    parser.add_argument('-O','--output-dir', help='Output-Verzeichnis (erforderlich für Batch)')
    parser.add_argument('--pattern', default='*.pptx', help='Dateimuster für --input-dir')
    parser.add_argument('--recursive', action='store_true', help='Rekursiv in --input-dir suchen')
    #parser.add_argument('-t','--threads', type=int, default=min(32, os.cpu_count() or 4), help='Anzahl paralleler Threads pro Datei')
    parser.add_argument('-t','--threads', type=int, default=16, help='Anzahl paralleler Threads pro Datei')
    parser.add_argument('-q','--quality', type=int, default=90, help='Qualität für caesiumclt (0..100), höher = bessere Qualität / größere Datei')
    parser.add_argument('--min-savings', default=DEFAULT_MIN_SAVINGS, help="Mindestersparnis für caesiumclt (z. B. 2%%, 100KB, 1MB oder Bytes als Zahl)")
    parser.add_argument('--version', action='version', version=f'%(prog)s {__version__}',  help="Zeigt die Versionsnummer an" )
    
    args = parser.parse_args()

    print("Threads used:     ", args.threads," Threads")

    if args.quality < 0 or args.quality > 100:
        print('[ERROR] Ungültige Qualität. Erlaubt: 0..100')
        sys.exit(1)

    input_files: list[Path] = []
    if args.input:
        input_files.extend(expand_inputs(args.input))
    if args.input_dir:
        input_files.extend(collect_from_dir(Path(args.input_dir), args.pattern, args.recursive))

    if len(input_files) == 0:
        parser.print_help()
        sys.exit(1)

    batch_mode = len(input_files) > 1

    if batch_mode and not args.output_dir:
        print('[ERROR] Batch-Modus erkannt. Bitte -O/--output-dir angeben.')
        sys.exit(2)

    if not which('caesiumclt'):
        print("[ERROR] 'caesiumclt' nicht gefunden. Bitte installieren und in PATH verfügbar machen.")
        sys.exit(3)

    overall_before = 0
    overall_after = 0
    successes = 0
    failures = 0

    if batch_mode:
        out_dir = Path(args.output_dir).resolve()
        out_dir.mkdir(parents=True, exist_ok=True)
        print(f"Batch: {len(input_files)} Datei(en). Output-Verzeichnis: {out_dir}")
        for src in input_files:
            if not src.exists():
                print(f"- Übersprungen (nicht gefunden): {src}")
                failures += 1
                continue
            dst = out_dir / f"{src.stem}_compressed.pptx"
            res = process_single_deck(src, dst, args.threads, args.quality, args.min_savings)
            if res.ok:
                successes += 1
                overall_before += res.size_before
                overall_after += res.size_after
            else:
                failures += 1
                print(f"  Fehler: {src.name} -> {res.error}")
    else:
        src = input_files[0]
        if args.output_dir:
            Path(args.output_dir).mkdir(parents=True, exist_ok=True)
            dst = Path(args.output_dir) / f"{src.stem}_compressed.pptx"
        else:
            dst = Path(args.output).resolve() if args.output else src.with_name(f"{src.stem}_compressed.pptx")
        res = process_single_deck(src, dst, args.threads, args.quality, args.min_savings)
        if res.ok:
            successes += 1
            overall_before += res.size_before
            overall_after += res.size_after
        else:
            failures += 1
            print(f"  Fehler: {src.name} -> {res.error}")

    if batch_mode:
            
        print(f"====== Gesamt-Summary ======")
        print(f"[SUCCESS] Dateien erfolgreich: {successes}")
        
        if failures > 0:
            print(f"[FAILED] Dateien fehlgeschlagen: {failures}")

        if overall_before > 0:
            pct = round(100.0 * (overall_before - overall_after) / overall_before, 2)
        else:
            pct = 0.0
        print(f"Gesamtgröße vorher:  {human_mb(overall_before)} MB")
        print(f"Gesamtgröße nachher: {human_mb(overall_after)} MB")
        print(f"Gesamt-Ersparnis:    {pct}%")




if __name__ == '__main__':
    main()