import click

@click.command()
@click.option('-i', '--input', 'opt_fp_in', required=True,
  help='Input')
@click.option('-o', '--output', 'opt_fp_out', required=True,
  help='Output')
@click.option('-t', '--threads', 'opt_threads', default=4,
  help='Number of threads')
@click.pass_context
def cli(ctx, opt_fp_in, opt_fp_out, opt_threads):
  """Template for multithreading"""
  
  from functools import partial
  from multiprocessing.dummy import Pool as ThreadPool

  from tqdm import tqdm
  
  from app.utils.logger_utils import Logger

  log = Logger.getLogger()
  log.info('multithreaded template')

  # setup multithreading function
  def pool_process(item):
    # threaded function
    results = []
    try:
      # do something here with item
    except Exception as e:
      log.debug(f'Error: {e}')
    pbar.update(1)
    return results

  # setup multithreading data holds
  pool_items = []  # list of dicts to process
  pool_results = []
  num_items = len(pool_items)

  # run the multithreading with progress bar
  pbar = tqdm(total=num_items)
  pool_process = partial(pool_process)
  pool = ThreadPool(opt_threads) 
  with tqdm(total=num_items) as pbar:
    pool_results = pool.map(pool_process, pool_items)
  
  pbar.close()