#!/usr/bin/env python3

from __future__ import print_function
import sys
sys.path.append('/usr/share/botch')
from util import read_reduced_deps, read_weak_deps, read_fas


def checkfas(weak, droppable, fas, verbose=False):
    modsrc = 0
    fassize = 0
    notdroppable = 0

    result = list()
    for src, deps in fas:
        modsrc += 1
        for d in deps:
            fassize += 1
            if d not in droppable[src] and d not in weak:
                notdroppable += 1
                result.append((src, d))
    droppable = (fassize - notdroppable) / float(fassize)
    if verbose:
        print(modsrc, fassize, droppable, file=sys.stderr)
    return result


if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(
        description=("given any number of droppable dependencies and a " +
                     "feedback arc set, show which edges in the feedback " +
                     "arc set are not droppable"))
    parser.add_argument('--remove-weak', type=read_weak_deps,
                        help="A filename containing a list of weak build " +
                             "dependencies")
    parser.add_argument('--remove-reduced', type=read_reduced_deps,
                        help="One or more filename containing a list of " +
                             "droppable build dependencies, separated by " +
                             "commas.")
    parser.add_argument('fas', type=read_fas, help='A feedback arc set')
    parser.add_argument(
        '-v', '--verbose', action='store_true', help='be verbose')
    args = parser.parse_args()
    result = checkfas(args.remove_weak, args.droppable, args.fas, args.verbose)
    for r in result:
        print(r)