import hashlib
import random
import time

# Dummy lightweight LLM model function
def lightweight_llm(seed, difficulty_prefix):
    """
    Simulate the LLM finding a candidate hash starting with a given pattern.
    The seed is used to generate a random number and the difficulty_prefix is what we aim for.
    """
    random.seed(seed + time.time())
    candidate = f"{random.getrandbits(256):064x}"
    if candidate.startswith(difficulty_prefix):
        return candidate
    return None

def mine_block(block_data, difficulty_prefix='000'):
    """
    Simplified mining function using a lightweight LLM model.
    """
    seed = random.randint(0, 1 << 32)
    while True:
        candidate_hash = lightweight_llm(seed, difficulty_prefix)
        if candidate_hash:
            # Incorporate block data and candidate hash
            block_header = f"{block_data}{candidate_hash}"
            final_hash = hashlib.sha256(block_header.encode()).hexdigest()
            if final_hash.startswith(difficulty_prefix):
                print(f"Block mined with candidate hash: {candidate_hash}")
                return final_hash
        # Optionally update the seed to vary the input
        seed = random.randint(0, 1 << 32)

# Example block data and mining process
if __name__ == '__main__':
    block_data = "previous_hash:0000000000000000000, transactions: [...]"
    print("Starting mining process...")
    new_block_hash = mine_block(block_data, difficulty_prefix='0000')
    print(f"New block hash: {new_block_hash}")