#!/usr/bin/env python3

# Simple graph query utility
# useful for getting answers from .dot files produced by bitbake -g
#
# Written by: Paul Eggleton <paul.eggleton@linux.intel.com>
#
# Copyright 2013 Intel Corporation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

import sys

def get_path_networkx(dotfile, fromnode, tonode):
    try:
        import networkx
    except ImportError:
        print('ERROR: Please install the networkx python module')
        sys.exit(1)

    graph = networkx.DiGraph(networkx.nx_pydot.read_dot(dotfile))
    def node_missing(node):
        import difflib
        close_matches = difflib.get_close_matches(node, graph.nodes(), cutoff=0.7)
        if close_matches:
            print('ERROR: no node "%s" in graph. Close matches:\n  %s' % (node, '\n  '.join(close_matches)))
        sys.exit(1)

    if not fromnode in graph:
        node_missing(fromnode)
    if not tonode in graph:
        node_missing(tonode)
    return networkx.all_simple_paths(graph, source=fromnode, target=tonode)


def find_paths(args, usage):
    if len(args) < 3:
        usage()
        sys.exit(1)

    fromnode = args[1]
    tonode = args[2]

    path = None
    for path in get_path_networkx(args[0], fromnode, tonode):
        print(" -> ".join(map(str, path)))
    if not path:
        print("ERROR: no path from %s to %s in graph" % (fromnode, tonode))
        sys.exit(1)

def main():
    import optparse
    parser = optparse.OptionParser(
        usage = '''%prog [options] <command> <arguments>

Available commands:
    find-paths <dotfile> <from> <to>
        Find all of the paths between two nodes in a dot graph''')

    #parser.add_option("-d", "--debug",
    #        help = "Report all SRCREV values, not just ones where AUTOREV has been used",
    #        action="store_true", dest="debug", default=False)

    options, args = parser.parse_args(sys.argv)
    args = args[1:]

    if len(args) < 1:
        parser.print_help()
        sys.exit(1)

    if args[0] == "find-paths":
        find_paths(args[1:], parser.print_help)
    else:
        parser.print_help()
        sys.exit(1)


if __name__ == "__main__":
    main()