#!/usr/bin/env python3
"""Download the full set of 47 HDRI environment maps used by DeformX renders.

The minimal asset bundle ships only 4 HDRIs to keep the download small. The
DeformX paper randomizes the dome light over all 47 listed here. They are all
CC0 from Poly Haven (https://polyhaven.com), so this script just fetches them
directly rather than re-hosting them.

Usage:
    python scripts/fetch_full_backgrounds.py                  # into ../background
    python scripts/fetch_full_backgrounds.py --out /some/dir
    python scripts/fetch_full_backgrounds.py --resolution 2k  # smaller download
"""

from __future__ import annotations

import argparse
import sys
import urllib.error
import urllib.request
from pathlib import Path

# The 47 Poly Haven HDRIs used for background randomization.
HDRI_SLUGS = [
    "abandoned_factory_canteen_02",
    "abandoned_tiled_room",
    "bambanani_sunset",
    "bell_tower",
    "boiler_room",
    "burnt_warehouse",
    "cedar_bridge_2",
    "christmas_photo_studio_04",
    "church_stairway",
    "cobblestone_street_night",
    "creepy_bathroom",
    "decor_shop",
    "drachenfels_cellar",
    "empty_workshop",
    "ferndale_studio_01",
    "glasshouse_interior",
    "golden_bay",
    "hangar_interior",
    "industrial_pipe_and_valve_01",
    "industrial_wooden_attic",
    "industrial_workshop_foundry",
    "little_paris_eiffel_tower",
    "machine_shop_01",
    "machine_shop_02",
    "machine_shop_03",
    "metro_noord",
    "moon_lab",
    "newman_cafeteria",
    "outdoor_chapel",
    "palermo_sidewalk",
    "peppermint_powerplant",
    "rogland_clear_night",
    "shanghai_bund",
    "small_workshop",
    "street_lamp",
    "studio_small_09",
    "sundowner_deck",
    "sunflowers_puresky",
    "the_sky_is_on_fire",
    "university_workshop",
    "vintage_measuring_lab",
    "warm_bar",
    "warm_restaurant_night",
    "workshop",
    "wrestling_gym",
    "yaris_interior_garage",
    "zwartkops_start_morning",
]

URL_TEMPLATE = "https://dl.polyhaven.org/file/ph-assets/HDRIs/hdr/{res}/{slug}_{res}.hdr"


def parse_args() -> argparse.Namespace:
    p = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    p.add_argument(
        "--out",
        type=Path,
        default=Path(__file__).resolve().parents[1] / "background",
        help="Destination directory (default: <bundle>/background).",
    )
    p.add_argument(
        "--resolution",
        default="4k",
        choices=["1k", "2k", "4k", "8k"],
        help="HDRI resolution to fetch (default: 4k, matching the paper).",
    )
    p.add_argument("--force", action="store_true", help="Re-download files that already exist.")
    return p.parse_args()


def download(url: str, dest: Path) -> None:
    """Download to a temp file, then move into place, so interrupts don't leave partials."""
    tmp = dest.with_suffix(dest.suffix + ".part")
    with urllib.request.urlopen(url, timeout=120) as resp, tmp.open("wb") as fh:
        while chunk := resp.read(1 << 20):
            fh.write(chunk)
    tmp.replace(dest)


def main() -> int:
    args = parse_args()
    args.out.mkdir(parents=True, exist_ok=True)

    total = len(HDRI_SLUGS)
    fetched = skipped = 0
    failures: list[tuple[str, str]] = []

    for i, slug in enumerate(HDRI_SLUGS, 1):
        name = f"{slug}_{args.resolution}.hdr"
        dest = args.out / name

        if dest.exists() and not args.force:
            print(f"[{i:2d}/{total}] skip (exists)  {name}", flush=True)
            skipped += 1
            continue

        url = URL_TEMPLATE.format(res=args.resolution, slug=slug)
        print(f"[{i:2d}/{total}] downloading    {name}", flush=True)
        try:
            download(url, dest)
            fetched += 1
        except (urllib.error.URLError, OSError) as exc:
            print(f"    FAILED: {exc}", file=sys.stderr, flush=True)
            failures.append((name, str(exc)))

    print(f"\nDone: {fetched} downloaded, {skipped} already present, {len(failures)} failed -> {args.out}")
    if failures:
        print("\nFailed downloads:", file=sys.stderr)
        for name, exc in failures:
            print(f"  {name}: {exc}", file=sys.stderr)
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())