import io
import importlib.machinery
import os
import sys
from optparse import OptionParser

from .profile import runctx


def main():

    usage = "profile.py [-o output_file_path] [-s sort] [-m module | scriptfile] [arg] ..."
    parser = OptionParser(usage=usage)
    parser.allow_interspersed_args = False
    parser.add_option('-o', '--outfile', dest="outfile",
        help="Save stats to <outfile>", default=None)
    parser.add_option('-m', dest="module", action="store_true",
        help="Profile a library module.", default=False)
    parser.add_option('-s', '--sort', dest="sort",
        help="Sort order when printing to stdout, based on pstats.Stats class",
        default=-1)

    if not sys.argv[1:]:
        parser.print_usage()
        sys.exit(2)

    (options, args) = parser.parse_args()
    sys.argv[:] = args

    # The script that we're profiling may chdir, so capture the absolute path
    # to the output file at startup.
    if options.outfile is not None:
        options.outfile = os.path.abspath(options.outfile)

    if len(args) > 0:
        if options.module:
            import runpy
            code = "run_module(modname, run_name='__main__')"
            globs = {
                'run_module': runpy.run_module,
                'modname': args[0]
            }
        else:
            progname = args[0]
            sys.path.insert(0, os.path.dirname(progname))
            with io.open_code(progname) as fp:
                code = compile(fp.read(), progname, 'exec')
            spec = importlib.machinery.ModuleSpec(name='__main__', loader=None,
                                                  origin=progname)
            globs = {
                '__spec__': spec,
                '__file__': spec.origin,
                '__name__': spec.name,
                '__package__': None,
                '__cached__': None,
            }
        try:
            runctx(code, globs, None, options.outfile, options.sort)
        except BrokenPipeError as exc:
            # Prevent "Exception ignored" during interpreter shutdown.
            sys.stdout = None
            sys.exit(exc.errno)
    else:
        parser.print_usage()
    return parser

# When invoked as main program, invoke the profiler on a script
if __name__ == '__main__':
    main()