#!/usr/bin/env python3
"""
Download VLM-Gym inference dataset from Hugging Face Hub.

Usage:
    # Download everything
    python load_from_hf.py --output_dir ./inference_dataset

    # Download only test sets (no large assets)
    python load_from_hf.py --output_dir ./inference_dataset --subset test_sets

    # Download specific difficulty
    python load_from_hf.py --output_dir ./inference_dataset --subset easy

Examples:
    from load_from_hf import download_dataset, get_dataset_path

    # Download and get path
    dataset_path = download_dataset()

    # Use in your code
    test_set_easy = dataset_path / "test_set_easy"
"""

import argparse
from pathlib import Path
from typing import Optional, List

from huggingface_hub import snapshot_download, hf_hub_download

REPO_ID = "VisGym/inference-dataset"

# Define subsets for selective downloading
SUBSETS = {
    "test_sets": ["test_set_easy", "test_set_hard"],
    "initial_states": ["initial_states_easy", "initial_states_hard"],
    "easy": ["test_set_easy", "initial_states_easy"],
    "hard": ["test_set_hard", "initial_states_hard"],
    "partial_datasets": ["partial_datasets"],
    "all": [
        "test_set_easy",
        "test_set_hard",
        "initial_states_easy",
        "initial_states_hard",
        "partial_datasets",
    ],
}


def download_dataset(
    output_dir: Optional[str] = None,
    subset: str = "all",
    repo_id: str = REPO_ID,
    token: Optional[str] = None,
) -> Path:
    """
    Download VLM-Gym inference dataset from Hugging Face Hub.

    Args:
        output_dir: Directory to download to. If None, uses HF cache.
        subset: Which subset to download. Options:
            - "all": Everything (default)
            - "test_sets": Only test_set_easy and test_set_hard
            - "initial_states": Only initial_states_easy and initial_states_hard
            - "easy": Only easy difficulty (test_set + initial_states)
            - "hard": Only hard difficulty (test_set + initial_states)
            - "partial_datasets": Only the large asset files
        repo_id: Hugging Face repository ID
        token: Optional HF token for private repos

    Returns:
        Path to the downloaded dataset directory
    """
    if subset not in SUBSETS:
        raise ValueError(f"Unknown subset: {subset}. Choose from: {list(SUBSETS.keys())}")

    folders = SUBSETS[subset]

    # Build allow_patterns for the folders we want
    allow_patterns = [f"{folder}/**" for folder in folders]

    print(f"Downloading subset '{subset}' from {repo_id}...")
    print(f"Folders: {folders}")

    local_dir = snapshot_download(
        repo_id=repo_id,
        repo_type="dataset",
        local_dir=output_dir,
        allow_patterns=allow_patterns,
        token=token,
    )

    print(f"Downloaded to: {local_dir}")
    return Path(local_dir)


def get_dataset_path(
    output_dir: Optional[str] = None,
    subset: str = "all",
    repo_id: str = REPO_ID,
    token: Optional[str] = None,
) -> Path:
    """
    Get path to dataset, downloading if necessary.

    This is a convenience wrapper that downloads the dataset if not present
    and returns the path.
    """
    return download_dataset(output_dir, subset, repo_id, token)


def list_available_subsets():
    """Print available subsets and their contents."""
    print("Available subsets:")
    for name, folders in SUBSETS.items():
        print(f"  {name}: {', '.join(folders)}")


def main():
    parser = argparse.ArgumentParser(
        description="Download VLM-Gym inference dataset from Hugging Face Hub"
    )
    parser.add_argument(
        "--output_dir",
        type=str,
        default=None,
        help="Output directory (default: HF cache)",
    )
    parser.add_argument(
        "--subset",
        type=str,
        default="all",
        choices=list(SUBSETS.keys()),
        help="Which subset to download",
    )
    parser.add_argument(
        "--repo_id",
        type=str,
        default=REPO_ID,
        help="Hugging Face repository ID",
    )
    parser.add_argument(
        "--token",
        type=str,
        default=None,
        help="Hugging Face token (for private repos)",
    )
    parser.add_argument(
        "--list-subsets",
        action="store_true",
        help="List available subsets and exit",
    )

    args = parser.parse_args()

    if args.list_subsets:
        list_available_subsets()
        return

    download_dataset(
        output_dir=args.output_dir,
        subset=args.subset,
        repo_id=args.repo_id,
        token=args.token,
    )


if __name__ == "__main__":
    main()