#!/usr/bin/python
#
# Makefile generator by Unavowed (unavowed at vexillium org)
# This code is public domain.
#

import sys, os, stat

class Language:
  def __init__(self, suffixes):
    self.files = []
    self.suffixes = suffixes
    self.suffixes_present = {}
  
  def add_file(self, fname):
    for s in self.suffixes:
      if fname.endswith('.' + s):
        self.files.append(fname)
	self.suffixes_present[s] = True
	return True
    return False

  def is_present(self):
    return (len(self.files) > 0)

  def get_suffixes(self):
    return [s for s in self.suffixes_present.keys()]
  
  def get_files(self):
    return self.files

def print_list(lst, out):
  if len(lst) == 0:
    return
  out.write(lst[0])
  if len(lst) == 1:
    return
  for l in lst[1:]:
    out.write(' ' + l)

def print_files(lang, out):
  if not lang.is_present():
    return
  files = [f for f in lang.get_files()]
  files.sort()
  print_list(files, out)
    
lang_c = Language(['c'])
lang_cpp = Language(['cpp', 'cc'])

languages = {
  'C'   : lang_c,
  'C++' : lang_cpp
}

target = 'a.out'

if len(sys.argv) > 1:
  target = sys.argv[1]

for f in os.listdir('.'):
  st = os.stat(f)
  if not stat.S_ISREG(st.st_mode):
    continue
  for lang in languages.itervalues():
    if lang.add_file(f):
      break

is_c = lang_c.is_present()
is_cpp = lang_cpp.is_present()

if not (is_c or is_cpp):
  sys.exit(0)

suffixes = []

for lang in languages.itervalues():
  if lang.is_present():
    ls = lang.get_suffixes()
    if len(ls) > 1:
      sys.stderr.write(
        'No more than one suffix is permitted per language.\n')
      sys.stderr.write('Ensure there is only one of: ')
      print_list(ls, sys.stderr)
      sys.stderr.write('.\n')
      sys.exit(1)
    suffixes.append('.' + ls[0])

if is_c:
  c_suffix = lang_c.get_suffixes()[0]

if is_cpp:
  cpp_suffix = lang_cpp.get_suffixes()[0]
      
print 'CC = gcc'

if is_cpp:
  print 'CXX = g++'

if is_c:
  print 'CFLAGS ='

if is_cpp:
  print 'CXXFLAGS ='

print 'LDFLAGS ='

if is_cpp:
  print 'LIBS = -lstdc++'
else:
  print 'LIBS ='

print 'TARGET = ' + target
print

sys.stdout.write('.SUFFIXES: ')
suffixes.sort()
print_list(suffixes, sys.stdout)
print
print

if is_c and is_cpp:
  sys.stdout.write('CSRC = ')
  print_files(lang_c, sys.stdout)
  print
  sys.stdout.write('CXXSRC = ')
  print_files(lang_cpp, sys.stdout)
  print
else:
  sys.stdout.write('SRC = ')
  for lang in languages.itervalues():
    if lang.is_present():
      print_files(lang, sys.stdout)
      break
  print

print

sys.stdout.write('OBJ = ')

if is_c and is_cpp:
  print '$(CSRC:.%s=.o) $(CXXSRC:.%s=.o)' % (c_suffix, cpp_suffix)
elif is_c:
  print '$(SRC:.%s=.o)' % c_suffix
else:
  print '$(SRC:.%s=.o)' % cpp_suffix

print

print 'all: $(TARGET)'
print

print '$(TARGET): $(OBJ)'
print '\t$(CC) $(LDFLAGS) -o $(TARGET) $(OBJ) $(LIBS)'
print

if is_c:
  print '.%s.o:' % c_suffix
  print '\t$(CC) -c $(CFLAGS) -o $@ $<'
  print

if is_cpp:
  print '.%s.o:' % cpp_suffix
  print '\t$(CXX) -c $(CXXFLAGS) -o $@ $<'
  print

print 'clean:'
print '\trm -f $(OBJ) $(TARGET) core'