#!/usr/bin/env python

from sys import argv, stdout
from os import pathsep, listdir, environ, fdopen
from os.path import exists, isdir, realpath
from optparse import OptionParser, OptionValueError
from tempfile import mkstemp
from zipfile import is_zipfile

def StripPath(path):
    collected = []
    for p in path.split(pathsep):
        rp = realpath(p)
        # We keep the entry if it is a directory not empty or a zipfile
        try :
            if exists(rp) and ((isdir(rp) and listdir(rp)) 
                               or is_zipfile(rp)) and p not in collected:
                collected.append(p)
        except OSError :
            pass
    return pathsep.join(collected)

def CleanVariable(varname, shell, out):
    if environ.has_key(varname):
        pth = StripPath(environ[varname])
        if shell == "csh" or shell.find("csh") != -1 :
            out.write("setenv %s %s\n" % (varname, pth))
        elif shell == "sh" or shell.find("sh") != -1 :
            out.write("export %s=%s\n" % (varname, pth))
        elif shell == "bat" :
            out.write("set %s=%s\n" % (varname, pth))
    

def _check_output_options_cb(option, opt_str, value, parser):
    if opt_str == "--mktemp" :
        if parser.values.output != stdout :
            raise OptionValueError("--mktemp cannot be used at the same time as --output")
        else : 
            parser.values.mktemp = True
            fd, outname = mkstemp()
            parser.values.output = fdopen(fd, "w")
            print outname
    elif opt_str == "--output" or opt_str == "-o" :
        if parser.values.mktemp:
            raise OptionValueError("--mktemp cannot be used at the same time as --output")
        else :
            parser.values.output = open(value, "w")


if __name__ == '__main__':
    
    parser = OptionParser()

    parser.add_option("-e", "--env",
                      action="append",
                      dest="envlist",
                      metavar="PATHVAR",
                      help="add environment variable to be processed")
    parser.add_option("--shell", action="store", dest="shell", type="choice", metavar="SHELL",
                      choices = ['csh','sh','bat'],
                      help="select the type of shell to use")
    
    parser.set_defaults(output=stdout)
    parser.add_option("-o", "--output", action="callback", metavar="FILE",
                      type = "string", callback = _check_output_options_cb,
                      help="(internal) output the command to set up the environment ot the given file instead of stdout")
    parser.add_option("--mktemp", action="callback",
                      dest="mktemp",
                      callback = _check_output_options_cb,
                      help="(internal) send the output to a temporary file and print on stdout the file name (like mktemp)")
    
    options, args = parser.parse_args()

    if not options.shell and environ.has_key("SHELL"):
        options.shell = environ["SHELL"]
        

    if options.envlist:
        for v in options.envlist :
            CleanVariable(v, options.shell, options.output)

    for a in args:
        print StripPath(a)