#!/usr/bin/python3

import networkx as nx
import sys
from collections import Counter

def longest_path(G):
    dist = {} # stores [node, distance] pair
    for node in nx.topological_sort(G):
        # pairs of dist,node for all incoming edges
        pairs = [(dist[v][0]+1,v) for v in G.pred[node]]
        if pairs:
            dist[node] = max(pairs)
        else:
            dist[node] = (0, node)
    node,(length,_)  = max(list(dist.items()), key=lambda x:x[1])
    path = []
    while length > 0:
        path.append(node)
        length,node = dist[node]
    return list(reversed(path))


filename = sys.argv[1]


g = nx.DiGraph()

with open(filename,'r') as f:
    for line in f:
        g.add_edge(*(line.strip().split('->')))


print(nx.info(g))
degree_sequence=sorted(list(nx.degree(g).values()),reverse=True)
print(Counter(degree_sequence))

for i in range(15):
    for node in g.nodes():
        if g.in_degree(node) == 0:
            g.remove_node(node)

    print(nx.info(g))

#print nx.is_directed_acyclic_graph(g)
#print list(nx.simple_cycles(g))
degree_sequence=sorted(list(nx.degree(g).values()),reverse=True)
print(Counter(degree_sequence))

#print nx.diameter(g)

def rev(string):
    if string[-1] == '\'':
        return string[:-1]
    else:
        return string+'\''

#for edge in g.edges():
#    g.add_edge(rev(edge[1]), rev(edge[0]))
    #print edge
    #print rev(edge[1]), rev(edge[0])

print(nx.info(g))
print([len(item) for item in nx.weakly_connected_components(g)])


nx.write_graphml(g, filename.split('.')[0]+'.graphml')

with open(sys.argv[2],'w') as f:
    for edge in nx.dfs_edges(g):
        f.write('{} {}\n'.format(edge[0],edge[1]))

f.close()