orbitx.py

#!/usr/bin/env python3

"""
main() for OrbitX. Can launch one of several OrbitX programs.

Look in the submodules of orbitx.programs for different programs.
"""

import argparse
import logging
import sys
import time
import warnings
from pathlib import Path

import vpython

from orbitx import logs
from orbitx import programs
from orbitx.graphics.flight import launcher

log = logging.getLogger('orbitx')


def log_git_info():
    """For ease in debugging, try to get some version information.
    This should never throw a fatal error, it's just nice-to-know stuff.
    But if I get a logfile from someone at spacesim, this will help to make
    sure they're on the latest version."""
    try:
        git_dir = Path('.git')
        head_file = git_dir / 'HEAD'
        with head_file.open() as f:
            head_contents = f.readline().strip()
            log.info(f'Contents of .git/HEAD: {head_contents}')
        if head_contents.split()[0] == 'ref:':
            hash_file = git_dir / head_contents.split()[1]
            with hash_file.open() as f:
                log.info(f'Current reference hash: {f.readline().strip()}')
    except FileNotFoundError:
        return


def vpython_error_message():
    """Lets the user know that something bad happened.
    Note, if there's no vpython canvas, this vpython code has no effect."""
    error_message = (
        "<p>&#9888; Sorry, spacesimmer! OrbitX has crashed for "
        "some reason.</p>"

        "<p>Any information that OrbitX has on the crash has "
        "been saved to a logfile. If you want to get this problem fixed,"
        " send the contents of the log file "
        "<blockquote>" +
        logs.logfile_name.replace('\\', '\\\\') +
        "</blockquote> "
        "to Patrick Melanson along with a description of what was "
        "happening in the program when it crashed.</p>"

        "<p>Again, thank you for using OrbitX!</p>"
    )
    vpython.canvas.get_selected().append_to_caption(f"""<script>
        if (document.querySelector('div.error') == null) {{
            error_div = document.createElement('div');
            error_div.className = 'error';
            error_div.innerHTML = "{error_message}";
            document.querySelector('body').prepend(error_div);
        }}
    </script>""")
    vpython.canvas.get_selected().append_to_caption("""<style>
        .error {
            color: #D8000C !important;
            background-color: #FFBABA;
            margin: 10px 0;
            padding: 10px;
            border-radius: 5px 5px 5px 5px;
            width: 700px;
        }
        span.code {
            color: #D8000C !important;
            font-family: monospace;
        }
        blockquote {
            font-family: monospace;
        }
    </style>""")

    time.sleep(0.1)  # Let vpython send out this update


def main():
    """Delegate work to one of the OrbitX programs."""

    log_git_info()

    parser = argparse.ArgumentParser()
    parser.add_argument('-v', '--verbose', action='store_true', default=False,
                        help='Logs everything to both logfile and output.')

    parser.add_argument('--flamegraph', action='store_true', default=False,
                        help='Generating profiling reports, for a flamegraph.')
    parser.add_argument('--profile', action='store_true', default=False,
                        help='Profile and print simple stats at exit.')

    # Use the argument parsers that each program defines
    subparsers = parser.add_subparsers(help='Which OrbitX program to run',
                                       dest='program')

    for program in programs.LISTING:
        subparser = subparsers.add_parser(
            program.argparser.prog,
            add_help=False, parents=[program.argparser])
        subparser.set_defaults(main_loop=program.main)

    args = parser.parse_args()

    if args.verbose:
        logs.enable_verbose_logging()

    try:
        if args.program is None:
            # No CLI args were specified, get the needed information from the
            # user using a graphical launcher interface.
            launch = launcher.Launcher()
            args = parser.parse_args(launch.get_args())

        logs.make_program_logfile(args.program)
        args.main_loop(args)
    except KeyboardInterrupt:
        # We're expecting ctrl-C will end the program, hide the exception from
        # the user.
        pass
    except Exception as e:
        log.exception('Unexpected exception, exiting...')
        print(f'OrbitX got an unexpected exception! Check {logs.logfile_name} for logs if you\'re an orbitx developer.')
        print('Or, send the logfile to Patrick.')

        vpython_error_message()

        # The usual errors that result from stale grpc/protobuf definitions are
        # attribute errors (like entity.x throwing an AttributeError), or
        # GRPC errors.
        if isinstance(e, (AttributeError, ValueError)) or \
                hasattr(e, '__module__') and (
                'grpc' in e.__module__ or 'google' in e.__module__):
            proto_file = Path('orbitx', 'orbitx.proto')
            generated_file = Path('orbitx', 'orbitx_pb2.py')
            if not generated_file.is_file():
                log.warning('================================================')
                log.warning(f'{proto_file} does not exist.')
            elif proto_file.stat().st_mtime > generated_file.stat().st_mtime:
                log.warning('================================================')
                log.warning(f'{proto_file} is newer than {generated_file}.')
            else:
                # We thought that generated protobuf definitions were out of
                # date, but it doesn't actually look like that's the case.
                sys.exit(1)

            log.warning('A likely fix for this fatal exception is to run the')
            log.warning('generate-protobuf script for your platform!')
            log.warning('You\'ll have to do this every time you change')
            log.warning(str(proto_file))
            log.warning('================================================')

        # We don't exit by allowing the exception to be uncaught, because then
        # it would be printed again unneccessarily.
        sys.exit(1)


if __name__ == '__main__':
    main()