import os
import gzip
import glob
import click

S2_DIR = '/media/blue/undisclosed/semantic-scholar/corpus-2018-05-03'
DATA_DIR = '/home/lens/undisclosed/megapixels_dev/datasets/s2/db_papers'

@click.command()
@click.option('--input', '-i', default='ids.json', help='List of IDs to extract from the big dataset.')
def fetch_entries(fn):
  ids = load_id_lookup(fn)
  for filename in glob.iglob('{}/*.gz'.format(S2_DIR)):
    search_dataset_shard('{}/{}'.format(S2_DIR, filename), ids)

def search_dataset_shard(fn, ids):
  with gzip.open(fn, 'r') as f:
    for line in f.readlines():
      process_paper(str(line)[2:-3])

def process_paper(line):
  paper_id = line.split('"id":"', 2)[1].split('"', 2)[0]
  if paper_id in ids:
    print(paper_id)
    del ids[paper_id]
    write_paper(paper_id, line)

def load_id_lookup(fn):
  lookup = {}
  ids = read_json(fn)
  for paper_id in ids:
    path = paper_path(paper_id)
    if not os.path.exists(path):
      lookup[paper_id] = True
  return lookup

def paper_path(paper_id):
  return '{}/{}/{}'.format(DATA_DIR, paper_id[0:3], paper_id)
  
def write_paper(paper_id, data):
  dir = paper_path(paper_id)
  fn = dir + '/paper.json'
  if os.path.exists(fn):
    return
  os.makedirs(dir, exist_ok=True)
  with open(fn, 'wb') as f:
    f.write(data)

if __name__ == '__main__':
  fetch_entries()