"""
Merge metadata from all GPUs after multi-GPU preprocessing.

Run this after all GPUs have completed processing.
"""

import json
from pathlib import Path
import argparse


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--output-dir', type=str, required=True, help='Output directory')
    parser.add_argument('--num-gpus', type=int, default=16, help='Total number of GPUs')
    args = parser.parse_args()

    output_dir = Path(args.output_dir)

    print("=" * 80)
    print("Merging Multi-GPU Metadata")
    print("=" * 80)

    all_metadata = []
    total_processed = 0
    total_skipped = 0
    total_previews = 0
    missing_gpus = []

    for gpu_id in range(args.num_gpus):
        metadata_path = output_dir / f'metadata_gpu{gpu_id:02d}.json'

        if not metadata_path.exists():
            print(f"⚠️  Missing: GPU {gpu_id} (file not found)")
            missing_gpus.append(gpu_id)
            continue

        with open(metadata_path, 'r') as f:
            metadata = json.load(f)
            all_metadata.append(metadata)
            total_processed += metadata['processed_episodes']
            total_skipped += metadata['skipped_episodes']
            total_previews += metadata['preview_videos']

        print(f"✓ GPU {gpu_id:2d}: {metadata['processed_episodes']:5d} processed, "
              f"{metadata['skipped_episodes']:4d} skipped, "
              f"{metadata['preview_videos']:2d} previews")

    print("\n" + "=" * 80)
    print("Summary")
    print("=" * 80)
    print(f"  GPUs completed: {len(all_metadata)}/{args.num_gpus}")
    print(f"  Total processed: {total_processed}")
    print(f"  Total skipped: {total_skipped}")
    print(f"  Total previews: {total_previews}")

    if missing_gpus:
        print(f"\n⚠️  Missing GPUs: {missing_gpus}")
        print("   Some GPUs may still be running. Check logs:")
        for gpu_id in missing_gpus:
            machine_id = gpu_id // 8
            local_gpu = gpu_id % 8
            log_file = output_dir / f'log_machine{machine_id}_gpu{local_gpu}.txt'
            if log_file.exists():
                print(f"     tail -f {log_file}")

    # Save merged metadata
    merged_metadata = {
        'num_gpus_completed': len(all_metadata),
        'num_gpus_total': args.num_gpus,
        'total_processed_episodes': total_processed,
        'total_skipped_episodes': total_skipped,
        'total_preview_videos': total_previews,
        'missing_gpus': missing_gpus,
        'gpu_metadata': all_metadata,
        'camera_params': all_metadata[0]['camera_params'] if all_metadata else {},
        'point_distribution': all_metadata[0]['point_distribution'] if all_metadata else {},
        'image_resolution': all_metadata[0]['image_resolution'] if all_metadata else [],
        'max_frames_per_episode': all_metadata[0]['max_frames_per_episode'] if all_metadata else 400,
        'cotracker_model': all_metadata[0]['cotracker_model'] if all_metadata else '',
        'cotracker_chunking': all_metadata[0]['cotracker_chunking'] if all_metadata else '',
    }

    merged_path = output_dir / 'metadata_merged.json'
    with open(merged_path, 'w') as f:
        json.dump(merged_metadata, f, indent=2)

    print(f"\n✓ Merged metadata saved: {merged_path}")
    print("=" * 80)

    # Count NPZ files
    data_dir = output_dir / 'data'
    if data_dir.exists():
        npz_files = list(data_dir.glob('episode_*.npz'))
        print(f"\nNPZ files in data/: {len(npz_files)}")

    # Count preview videos
    preview_dir = output_dir / 'preview_videos'
    if preview_dir.exists():
        video_files = list(preview_dir.glob('preview_episode_*.mp4'))
        print(f"Preview videos: {len(video_files)}")

    print("\nProcessing complete! ✓")


if __name__ == "__main__":
    main()