#!/usr/bin/env python3

from __future__ import annotations

import argparse
import csv
import errno
import json
import os
import shutil
from pathlib import Path
from typing import Any, Dict, Iterable, List


DEFAULT_TARGET_COLUMNS = [
    "lcd",
    "pld",
    "void_fraction",
    "surface_area_m2g",
    "surface_area_m2cm3",
]


def parse_target_columns(raw: str) -> List[str]:
    cols = [c.strip() for c in raw.split(",") if c.strip()]
    if not cols:
        raise ValueError("Список target-колонок пуст.")
    return cols


def get_nested_value(data: Any, path: str) -> Any:
    current = data
    for part in path.split("."):
        if isinstance(current, dict):
            if part not in current:
                return None
            current = current[part]
            continue

        if isinstance(current, list) and part.isdigit():
            idx = int(part)
            if idx < 0 or idx >= len(current):
                return None
            current = current[idx]
            continue

        return None

    return current


def normalize_scalar(value: Any) -> Any:
    if value is None:
        return ""
    if isinstance(value, (str, int, float, bool)):
        return value
    return json.dumps(value, ensure_ascii=False)


def try_parse_float(value: Any) -> float | None:
    if isinstance(value, bool):
        return None
    if isinstance(value, (int, float)):
        return float(value)
    if isinstance(value, str):
        raw = value.strip()
        if not raw:
            return None
        try:
            return float(raw)
        except ValueError:
            return None
    return None


def all_targets_are_zero(row: Dict[str, Any], target_columns: List[str]) -> bool:
    for col in target_columns:
        num = try_parse_float(row.get(col))
        if num is None or num != 0.0:
            return False
    return True


def safe_link_or_copy(src: Path, dst: Path) -> bool:
    try:
        os.link(src, dst)
        return False
    except OSError as exc:
        if exc.errno not in {errno.EXDEV, errno.EPERM, errno.EOPNOTSUPP, errno.EACCES}:
            raise
        shutil.copy2(src, dst)
        return True


def place_cif_file(src: Path, dst: Path, file_op: str) -> bool:
    """
    Returns True if fallback to copy happened (only for hardlink mode), else False.
    """
    if file_op == "copy":
        shutil.copy2(src, dst)
        return False
    if file_op == "move":
        shutil.move(str(src), str(dst))
        return False
    if file_op == "symlink":
        os.symlink(src.resolve(), dst)
        return False
    if file_op == "hardlink":
        return safe_link_or_copy(src, dst)
    raise ValueError(f"Неизвестный file-op: {file_op}")


def iter_cif_files(hmof_dir: Path) -> Iterable[Path]:
    return sorted(p for p in hmof_dir.iterdir() if p.is_file() and p.suffix.lower() == ".cif")


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description=(
            "Создать структуру датасета для hMOF в стиле CoreMof/ASR: "
            "<out-dir>/raw/*.cif + <out-dir>/id_prop.csv"
        )
    )
    parser.add_argument(
        "--hmof-dir",
        type=Path,
        default=Path("hMOF"),
        help="Папка с исходными файлами *.cif и *.json (по умолчанию: hMOF)",
    )
    parser.add_argument(
        "--out-dir",
        type=Path,
        default=None,
        help="Куда собрать датасет (по умолчанию: <hmof-dir>/ASR)",
    )
    parser.add_argument(
        "--target-columns",
        default=",".join(DEFAULT_TARGET_COLUMNS),
        help=(
            "Target-колонки из JSON (через запятую). "
            "Поддерживаются и вложенные пути, например: adsorbent.id"
        ),
    )
    parser.add_argument(
        "--file-op",
        choices=["hardlink", "copy", "move", "symlink"],
        default="hardlink",
        help=(
            "Как поместить CIF в raw: hardlink/copy/move/symlink "
            "(по умолчанию: hardlink)"
        ),
    )
    parser.add_argument(
        "--overwrite-files",
        action="store_true",
        help="Перезаписывать уже существующие CIF в raw",
    )
    parser.add_argument(
        "--max-files",
        type=int,
        default=None,
        help="Ограничить количество обрабатываемых CIF (для теста)",
    )
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Проверка без записи файлов",
    )
    parser.add_argument(
        "--progress-every",
        type=int,
        default=5000,
        help="Как часто печатать прогресс (по умолчанию: 5000)",
    )
    return parser.parse_args()


def main() -> None:
    args = parse_args()

    hmof_dir = args.hmof_dir
    out_dir = args.out_dir or (hmof_dir / "ASR")
    raw_dir = out_dir / "raw"
    id_prop_path = out_dir / "id_prop.csv"
    target_columns = parse_target_columns(args.target_columns)

    if not hmof_dir.is_dir():
        raise FileNotFoundError(f"Папка не найдена: {hmof_dir}")

    cif_files = list(iter_cif_files(hmof_dir))
    if args.max_files is not None:
        cif_files = cif_files[: args.max_files]

    total = len(cif_files)
    if total == 0:
        raise RuntimeError(f"В {hmof_dir} не найдено ни одного .cif файла.")

    if not args.dry_run:
        raw_dir.mkdir(parents=True, exist_ok=True)
        out_dir.mkdir(parents=True, exist_ok=True)

    stats: Dict[str, int] = {
        "total_cif": total,
        "written_rows": 0,
        "missing_json": 0,
        "bad_json": 0,
        "skipped_all_zero_targets": 0,
        "removed_all_zero_from_raw": 0,
        "placed_files": 0,
        "already_present": 0,
        "hardlink_fallback_copy": 0,
    }
    missing_targets: Dict[str, int] = {col: 0 for col in target_columns}

    if args.dry_run:
        sink = open(os.devnull, "w", newline="", encoding="utf-8")
    else:
        sink = id_prop_path.open("w", newline="", encoding="utf-8")

    try:
        writer = csv.DictWriter(sink, fieldnames=["mof_id", *target_columns])
        writer.writeheader()

        for idx, cif_path in enumerate(cif_files, start=1):
            mof_id = cif_path.stem
            json_path = hmof_dir / f"{mof_id}.json"

            if not json_path.is_file():
                stats["missing_json"] += 1
                continue

            try:
                with json_path.open("r", encoding="utf-8") as f:
                    payload = json.load(f)
            except json.JSONDecodeError:
                stats["bad_json"] += 1
                continue

            row: Dict[str, Any] = {"mof_id": mof_id}
            for col in target_columns:
                value = get_nested_value(payload, col)
                if value is None:
                    missing_targets[col] += 1
                row[col] = normalize_scalar(value)

            raw_cif_path = raw_dir / cif_path.name

            # Пропускаем структуры, где все target-значения равны 0.0.
            if all_targets_are_zero(row, target_columns):
                if not args.dry_run and raw_cif_path.exists():
                    raw_cif_path.unlink()
                    stats["removed_all_zero_from_raw"] += 1
                stats["skipped_all_zero_targets"] += 1
                continue

            if not args.dry_run:
                if raw_cif_path.exists():
                    if args.overwrite_files:
                        raw_cif_path.unlink()
                        fallback_copy = place_cif_file(cif_path, raw_cif_path, args.file_op)
                        if fallback_copy:
                            stats["hardlink_fallback_copy"] += 1
                        stats["placed_files"] += 1
                    else:
                        stats["already_present"] += 1
                else:
                    fallback_copy = place_cif_file(cif_path, raw_cif_path, args.file_op)
                    if fallback_copy:
                        stats["hardlink_fallback_copy"] += 1
                    stats["placed_files"] += 1

            writer.writerow(row)
            stats["written_rows"] += 1

            if args.progress_every > 0 and idx % args.progress_every == 0:
                print(
                    f"[{idx}/{total}] rows={stats['written_rows']} "
                    f"missing_json={stats['missing_json']} bad_json={stats['bad_json']}"
                )
    finally:
        sink.close()

    print("=== hMOF preprocess done ===")
    print(f"hmof dir: {hmof_dir}")
    print(f"out dir: {out_dir}")
    print(f"raw dir: {raw_dir}")
    print(f"id_prop: {id_prop_path}")
    print(f"dry run: {args.dry_run}")
    print(f"file op: {args.file_op}")
    print(f"total cif: {stats['total_cif']}")
    print(f"id_prop rows written: {stats['written_rows']}")
    print(f"missing json: {stats['missing_json']}")
    print(f"bad json: {stats['bad_json']}")
    print(f"skipped all-zero targets: {stats['skipped_all_zero_targets']}")
    print(f"removed all-zero from raw: {stats['removed_all_zero_from_raw']}")
    print(f"placed cif files: {stats['placed_files']}")
    print(f"already present in raw: {stats['already_present']}")
    print(f"hardlink fallback copy: {stats['hardlink_fallback_copy']}")
    print(f"target columns: {', '.join(target_columns)}")

    for col in target_columns:
        print(f"missing target '{col}': {missing_targets[col]}")


if __name__ == "__main__":
    main()