import ptvsd
import argparse
import os
import sys
import json

if __name__ == "__main__":
    # Parse arguments.
    parser = argparse.ArgumentParser()
    parser.add_argument('script')
    parser.add_argument('--host', default='0.0.0.0')
    parser.add_argument('--port', default=8899, type=int)
    parser.add_argument('--json_list_args', default='[]')
    parser.add_argument('--current_working_directory', default=None, type=str)
    args = parser.parse_args()

    # Wait for debug client.
    print('Waiting for debug client...')
    ptvsd.enable_attach(address=(args.host, args.port), redirect_output=True)
    ptvsd.wait_for_attach()

    # Prepare environment and run the script.
    print('Client connected. Debugging...')

    # Empty the command line arguments.
    sys.argv = [args.script]

    # Set the current working directory.
    if args.current_working_directory == None:
        os.chdir(os.path.realpath(os.path.dirname(args.script)))
    else:
        os.chdir(os.path.realpath(args.current_working_directory))

    # Append the script path to "sys.path".
    sys.path.insert(0, os.path.realpath(os.path.dirname(args.script)))

    # Append the custom script arguments.
    args_list = json.loads(args.json_list_args)
    for arg in args_list:
        sys.argv.append(arg)

    # Execute the script.
    execfile(args.script)