import os
import lmdb
import re
import multiprocessing
from tqdm import tqdm

def sort_key(filename):
    # Extract frame number and cow id from filenames like:
    # "pmfeed_4_3_16_frame_10000_cow_1.jpg"
    match = re.search(r'frame_(\d+)_cow_(\d+)', filename)
    if match:
        frame_number = int(match.group(1))
        cow_id = int(match.group(2))
        return (frame_number, cow_id)
    return (float('inf'), float('inf'))

def read_image(args):
    image_folder, image_name = args
    image_path = os.path.join(image_folder, image_name)
    try:
        with open(image_path, 'rb') as f:
            image_data = f.read()
        return (image_name, image_data)
    except Exception as e:
        print(f"Error reading {image_name}: {e}")
        return None

def main():
    # Define your pathscon
    image_folder = 'all_crops_pmfeed_4_3_16'
    lmdb_path = 'lmdb_all_crops_pmfeed_4_3_16'
    
    # Create LMDB directory if it doesn't exist
    if not os.path.exists(lmdb_path):
        os.makedirs(lmdb_path)
    
    # List and sort JPEG files
    image_files = [f for f in os.listdir(image_folder) if f.endswith('.jpg')]
    sorted_files = sorted(image_files, key=sort_key)
    
    # For sanity check, take the first 20 images
    sanity_files = sorted_files
    
    # Prepare arguments for multiprocessing
    args = [(image_folder, image_name) for image_name in sanity_files]
    
    # Use multiprocessing Pool to read images concurrently
    with multiprocessing.Pool(processes=multiprocessing.cpu_count()) as pool:
        results = list(tqdm(pool.imap(read_image, args), total=len(args), desc="Reading images"))
    
    # Filter out any failed reads
    results = [res for res in results if res is not None]
    
    # Open LMDB environment with an appropriate map size (e.g., 10GB)
    map_size = 10 * 1024 * 1024 * 1024  # 10GB in bytes
    env = lmdb.open(lmdb_path, map_size=map_size)
    
    # Write the results into LMDB using a single write transaction
    with env.begin(write=True) as txn:
        for key, value in tqdm(results, desc="Writing to LMDB"):
            txn.put(key.encode('utf-8'), value)
    
    print("LMDB database creation complete for all images!")

if __name__ == '__main__':
    main()