#!/bin/python3
import os
import sys
import logging
import requests
import json
import argparse

logging.basicConfig(format='%(levelname)s\t- %(message)s')
logger = logging.getLogger()
logger.setLevel(logging.INFO)

state = {}

# session file - username(optional)
def list_subjects(args):

    parser = argparse.ArgumentParser()

    parser.add_argument('session', nargs='?', default=None)
    parser.add_argument('username', nargs='?', default=None)

    args = parser.parse_args()

    # Check if session file is valid
    if (not os.path.isfile(args.session)):
        logger.error("File '" + args.session + "' not found.")
        sys.exit(-1)

    if args.username:
        try: 
            subjects = json.loads(requests.get(f'http://{state['REP_ADDRESS']}/subject/list', json=json.dumps({'username' : args.username})))
            subjects.raise_for_status() 

        except requests.exceptions.RequestException as errex: 
            logger.error("Failed to obtain response from server.")
            sys.exit(1)

    else:
        try: 
            subjects = json.loads(requests.get(f'http://{state['REP_ADDRESS']}/subject/list'))
            subjects.raise_for_status() 

        except requests.exceptions.RequestException as errex: 
            logger.error("Failed to obtain response from server.")
            sys.exit(1)

    for s in subjects:
        sys.stdout.write(s['id'] + " - " + s['username'])


if __name__ == '__main__':
    list_subjects(sys.argv[1:])