#!/usr/bin/env python3
"""
Download script for structured3d dataset chunks from Hugging Face
"""

import os
import sys
from pathlib import Path

try:
    from huggingface_hub import hf_hub_download, list_repo_files
except ImportError:
    print("Error: huggingface_hub not installed")
    print("Install with: pip install huggingface_hub")
    sys.exit(1)

DATASET_NAME = "structured3d"
DEFAULT_REPO_ID = f"your-username/{DATASET_NAME}-dataset"

def download_chunks(repo_id, token=None):
    """Download structured3d chunks from Hugging Face."""
    
    try:
        # List files in the repository
        files = list_repo_files(repo_id=repo_id, repo_type="dataset", token=token)
        
        # Filter chunk files
        chunk_files = [f for f in files if f.startswith(f"{DATASET_NAME}/{DATASET_NAME}_part_")]
        
        if not chunk_files:
            print(f"Error: No chunks found in {repo_id}")
            print(f"Expected files like {DATASET_NAME}/{DATASET_NAME}_part_000")
            return False
        
        print(f"Found {len(chunk_files)} chunks to download")
        print(f"Warning: This will download ~307GB of data. Ensure you have enough disk space!")
        
        response = input("Continue with download? (y/N): ")
        if response.lower() != 'y':
            print("Download cancelled.")
            return False
        
        # Create chunks directory
        chunks_dir = Path("chunks")
        chunks_dir.mkdir(exist_ok=True)
        
        # Download each chunk
        for i, file_path in enumerate(sorted(chunk_files)):
            chunk_name = Path(file_path).name
            local_path = chunks_dir / chunk_name
            
            print(f"Downloading {chunk_name} ({i+1}/{len(chunk_files)})...")
            
            try:
                hf_hub_download(
                    repo_id=repo_id,
                    repo_type="dataset",
                    filename=file_path,
                    local_dir=".",
                    token=token
                )
                
                # Move to chunks directory
                downloaded_path = Path(file_path)
                if downloaded_path.exists():
                    downloaded_path.rename(local_path)
                
            except Exception as e:
                print(f"  ✗ Error downloading {chunk_name}: {e}")
                continue
        
        # Download helper scripts
        helper_files = [f for f in files if f.startswith(f"{DATASET_NAME}/") and f.endswith(('.sh', '.py'))]
        for file_path in helper_files:
            script_name = Path(file_path).name
            if script_name != "download.py":  # Don't overwrite ourselves
                print(f"Downloading {script_name}...")
                try:
                    hf_hub_download(
                        repo_id=repo_id,
                        repo_type="dataset", 
                        filename=file_path,
                        local_dir=".",
                        token=token
                    )
                    
                    # Move to current directory and make executable
                    downloaded_path = Path(file_path)
                    if downloaded_path.exists():
                        downloaded_path.rename(script_name)
                        if script_name.endswith('.sh'):
                            os.chmod(script_name, 0o755)
                        
                except Exception as e:
                    print(f"  ✗ Error downloading {script_name}: {e}")
        
        # Clean up empty directories
        dataset_dir = Path(DATASET_NAME)
        if dataset_dir.exists() and not any(dataset_dir.iterdir()):
            dataset_dir.rmdir()
        
        print(f"\n✓ Download complete!")
        print(f"Downloaded {len(chunk_files)} chunks to chunks/ directory")
        print("\nNext steps:")
        print("1. Run ./merge.sh to reassemble the original file")
        print("2. Run ./extract.sh to extract contents")
        print("\nWarning: Extraction will require additional ~307GB of disk space!")
        
        return True
        
    except Exception as e:
        print(f"Error accessing repository {repo_id}: {e}")
        return False

def main():
    import argparse
    
    parser = argparse.ArgumentParser(description=f"Download {DATASET_NAME} chunks from Hugging Face")
    parser.add_argument("repo_id", nargs="?", default=DEFAULT_REPO_ID, help="Hugging Face repository ID")
    parser.add_argument("--token", help="Hugging Face token (or set HF_TOKEN env var)")
    
    args = parser.parse_args()
    
    # Get token (optional for public repos)
    token = args.token or os.getenv("HF_TOKEN")
    
    print(f"Downloading from: {args.repo_id}")
    
    success = download_chunks(
        repo_id=args.repo_id,
        token=token
    )
    
    if not success:
        sys.exit(1)

if __name__ == "__main__":
    main()