#!/usr/bin/python

import argparse
import os.path
from cStringIO import StringIO
import subprocess
import sys

parser = argparse.ArgumentParser(description="Create a graphviz file of a makefile")
parser.add_argument("-C", "--directory", metavar="DIR", help="Change to directory DIR before reading the makefiles")
parser.add_argument("-f", "--file", help="Use FILE as makefile")
parser.add_argument("-o", "--output", default="makefile.gv", help="Output file")
parser.add_argument("-l", "--limit", type=int, help="Limit number of underscores in name")
parser.add_argument("target", nargs=argparse.REMAINDER, help="Make targets")

args = parser.parse_args()

makeargs = ["make", "-pn"]
if args.directory is not None:
  makeargs += ["-C", args.directory]
if args.file is not None:
  makeargs += ["-f", args.file]
makeargs += args.target

makeout = subprocess.check_output(makeargs)
makeoutfo = StringIO(makeout)

lastfiles = 0


for line in makeoutfo:
  if line == "# Files\n":
    lastfiles = makeoutfo.tell()

makeoutfo.seek(lastfiles)

with open(args.output, "wb") as outfile:
  outfile.write("digraph{splines=true;\n")
  for line in makeoutfo:
    linestrip = line.strip()
    if linestrip == "" or linestrip[0] == '#' or line[0] == '\t' or ":" not in line:
      continue
    target, depends = line.split(":", 1)
    target = target.strip()
    if target == "" or target[0] == ".":
      continue
    if args.limit is not None and target.count("_") >= args.limit:
      continue
    outfile.write("\"%s\" [label=\"%s\"];\n" % (target, os.path.basename(target)))
    deplist = [x.strip() for x in depends.split(" ") if x.strip() != ""]
    for dep in deplist:
      if dep[0] == ".":
        continue
      if args.limit is not None and dep.count("_") >= args.limit:
        continue
      outfile.write("\"%s\" [label=\"%s\"];\n" % (dep, os.path.basename(dep)))
      outfile.write("\"%s\" -> \"%s\";\n" % (target, dep))
  outfile.write("}\n")