#!/usr/bin/env python2.7
#
# Tool to find all pax flags from ebuilds.
#

__author__ = "Jens Kasten"
__copyright__ = "Copyright 2013, RSBAC"
__license__ = "GPL"
__version__ = "0.1"
__maintainer__ = "Jens Kasten"
__email__ = "igraltist@rsbac.org"
__status__ = "Testing"

import sys
import os
import re

# global list
PAX_MARKING = []
# exclude list for searching directories
EXCLUDE_DIRS = ["rsbac.dat", "metadata", "eclass", "distfiles"]
# search pattern for pax marking and pax flags and paths
PATTERN = re.compile(r'(?P<marker>paxctl|pax-mark) -(?P<flags>[pmsrx]+|[PMSRX]+) "\${.*}"(?P<path>.+)')

def _create_rsbac_pax(pax_file, pax_flags):
    """Add the created string to list."""
    temp = "attr_set_file_dir FILE %s pax_flags %s" % (pax_file, pax_flags)
    PAX_MARKING.append(temp)

def _multiple_files(files):
    """Split the bash shortcut into multiple full path names.
    e.g /usr/bin/wine{,-preloader}
    """
    file_list = []
    temp = files.replace("}", "").split("{")
    # add the base file to list
    file_list.append(temp[0])
    # split into list and append it to file_list
    for file_ in temp[1].split(","):
        # exclude empty string
        if len(file_) > 0:
            # concat and append to list
            file_list.append(temp[0] + file_)
    if len(file_list) == 0:
        raise Exception("wrong bash shortcut: %s" % files)
    return file_list
    
def _find_pax_marking(line):
    """Search for pattern in given line."""
    match = PATTERN.search(line)
    if match is not None:
        marker =  match.group("marker")
        pax_flags = match.group("flags")
        bin_path = match.group("path").split(" ")[0]
        
        print "*" * 80
        print line.strip()
        print "marker: %s; flags: %s; path: %s" % (marker, pax_flags, bin_path)
        
        # check for bash shortcuts
        if re.search("{", bin_path):
            for file_ in _multiple_files(bin_path):
                _create_rsbac_pax(file_, pax_flags)
        else:
            _create_rsbac_pax(bin_path, pax_flags)

def get_pax_marking(file_name):
    """Return pax marking flags as list or None."""
    try:
        with open(file_name) as fd:
            for line in fd.readlines():
                if len(line) > 0:
                    _find_pax_marking(line)                
        if len(PAX_MARKING) > 0:
            return PAX_MARKING
    except IOError, error:
        print error
    
def get_all_ebuilds():
    ebuild_list = []
    for apps in os.listdir("/usr/portage"):
        apps_dir = os.path.join("/usr/portage", apps)
        if apps in EXCLUDE_DIRS:
            continue
        if os.path.isfile(apps_dir):
           continue
        # iter over first sub directory e.g sys-apps
        for app in os.listdir(apps_dir):
            app_dir = os.path.join(apps_dir, app)
            if os.path.isdir(app_dir):
                for ebuild in os.listdir(app_dir):
                    ebuild_path = os.path.join(app_dir, ebuild)
                    if ebuild.endswith(".ebuild"):
                        ebuild_list.append(ebuild_path)
    return ebuild_list                    
 
if __name__ == "__main__":
    import argparse
    # parse commandline 
    parser = argparse.ArgumentParser()
    parser.add_argument("-f", "--FILE", type=str, 
        help="File to find pax marking flags.")
    args = parser.parse_args()
   
    # switch for single file
    if args.FILE is None:
        for ebuild in get_all_ebuilds():
            get_pax_marking(ebuild)
    else:
        get_pax_marking(args.FILE)

    #print PAX_MARKING