"""
Export ground-truth HTML from Hugging Face ``SALT-NLP/Design2Code-hf`` into
``data/gt_html/{id}.html``, aligned to ``data/ref_screenshots/{id}.png`` by
per-pixel MD5 (RGB).

Background:
  - Local ``design2code`` on disk may be image-only; this script re-fetches the
    HF split that includes the ``text`` column.
  - ``ref_screenshots/124.png`` is often truncated; when exactly one HF row is
    unmatched and stem ``124`` has no match, that row is treated as sample 124:
    optional PNG repair + ``gt_html/124.html``.

Usage:
  python scripts/export_design2code_gt_html.py
  python scripts/export_design2code_gt_html.py --output_dir data/gt_html --no-repair-124

Requires network; uses HF mirror by default (override with ``HF_ENDPOINT``).
"""

from __future__ import annotations

import argparse
import hashlib
import os
import shutil
import sys
from pathlib import Path

os.environ.setdefault("HF_ENDPOINT", "https://hf-mirror.com")
os.environ.setdefault("HF_HOME", os.environ.get("HF_HOME", "/root/rivermind-data/huggingface"))

from datasets import load_dataset
from PIL import Image

PROJECT_ROOT = Path(__file__).resolve().parent.parent


def _rgb_md5(pil: Image.Image) -> str:
    return hashlib.md5(pil.convert("RGB").tobytes()).hexdigest()


def _load_ref_hashes(ref_dir: Path) -> dict[str, str | None]:
    """stem -> md5 or None if unreadable."""
    out: dict[str, str | None] = {}
    for p in sorted(ref_dir.glob("*.png")):
        try:
            out[p.stem] = _rgb_md5(Image.open(p))
        except Exception:
            out[p.stem] = None
    return out


def main() -> int:
    parser = argparse.ArgumentParser(description="Export Design2Code GT HTML for ref_screenshots.")
    parser.add_argument("--ref_dir", type=Path, default=PROJECT_ROOT / "data" / "ref_screenshots")
    parser.add_argument("--output_dir", type=Path, default=PROJECT_ROOT / "data" / "gt_html")
    parser.add_argument("--hf_dataset", default="SALT-NLP/Design2Code-hf")
    parser.add_argument(
        "--repair-124",
        dest="repair_124",
        action="store_true",
        default=True,
        help="If one orphan HF row and stem 124 unmatched, save its image/HTML for 124 (default: on).",
    )
    parser.add_argument("--no-repair-124", dest="repair_124", action="store_false")
    args = parser.parse_args()

    ref_dir = args.ref_dir.resolve()
    out_dir = args.output_dir.resolve()
    if not ref_dir.is_dir():
        print(f"ref_dir not found: {ref_dir}", file=sys.stderr)
        return 1

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

    print(f"Loading {args.hf_dataset} (HF_ENDPOINT={os.environ.get('HF_ENDPOINT')})...")
    ds = load_dataset(args.hf_dataset, split="train")
    n = len(ds)
    print(f"  HF rows: {n}")

    stem_hash = _load_ref_hashes(ref_dir)
    hash_to_stem: dict[str, str] = {}
    for stem, h in stem_hash.items():
        if h is not None:
            hash_to_stem[h] = stem

    idx_to_stem: dict[int, str] = {}
    for i in range(n):
        h = _rgb_md5(ds[i]["image"])
        if h in hash_to_stem:
            idx_to_stem[i] = hash_to_stem[h]

    orphan_idx = [i for i in range(n) if i not in idx_to_stem]
    all_stems = set(stem_hash.keys())
    mapped_stems = set(idx_to_stem.values())
    stems_no_gt = sorted(all_stems - mapped_stems, key=lambda x: int(x))

    print(f"  Matched by image hash: {len(idx_to_stem)} / {n}")
    print(f"  HF rows without ref match: {orphan_idx}")
    print(f"  Ref stems without HF match: {stems_no_gt}")

    repair_pair: tuple[int, str] | None = None
    if (
        args.repair_124
        and len(orphan_idx) == 1
        and stems_no_gt == ["124", "484"]
        and stem_hash.get("124") is None
    ):
        repair_pair = (orphan_idx[0], "124")
        print(f"  Repair: assign HF row {repair_pair[0]} -> stem 124 (truncated PNG + GT).")
    elif args.repair_124 and len(orphan_idx) == 1 and "124" in stems_no_gt:
        # e.g. 484 already matched elsewhere
        only = [s for s in stems_no_gt if s != "484"]
        if len(only) == 1 and only[0] == "124" and stem_hash.get("124") is None:
            repair_pair = (orphan_idx[0], "124")
            print(f"  Repair: assign HF row {repair_pair[0]} -> stem 124.")

    written = 0
    for i in range(n):
        if repair_pair and i == repair_pair[0]:
            continue
        stem = idx_to_stem.get(i)
        if not stem:
            continue
        text = ds[i]["text"]
        if not isinstance(text, str) or not text.strip():
            print(f"  [skip] row {i} stem {stem}: empty text", file=sys.stderr)
            continue
        (out_dir / f"{stem}.html").write_text(text, encoding="utf-8")
        written += 1

    if repair_pair:
        i, stem = repair_pair
        text = ds[i]["text"]
        if not isinstance(text, str) or not text.strip():
            print(f"  [error] repair row {i} has empty text", file=sys.stderr)
            return 1
        png_path = ref_dir / f"{stem}.png"
        bak = ref_dir / f"{stem}.png.broken"
        if png_path.exists() and not bak.exists():
            shutil.copy2(png_path, bak)
            print(f"  Backed up broken PNG to {bak.name}")
        ds[i]["image"].convert("RGB").save(png_path, format="PNG")
        (out_dir / f"{stem}.html").write_text(text, encoding="utf-8")
        written += 1
        print(f"  Wrote repaired {png_path.name} and gt_html/{stem}.html")

    if "484" in stems_no_gt:
        print(
            "  Note: stem 484 has no row in Design2Code-hf (484 HF rows vs 485 local PNGs). "
            "No gt_html/484.html; drop or supply GT manually if needed.",
            file=sys.stderr,
        )

    print(f"Done. Wrote {written} HTML files under {out_dir}")
    return 0


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