#!/usr/bin/python
#-*- encoding: utf-8 -*-
"""
    File name: convert_ks.py
    Python Version: 2.7.3
    Licensed under the terms of the GNU GPL License version 2
"""

import tempfile
import shutil
import argparse
from lxml import etree

def write_package(convert_ks, xmlfile, groups, extra_pkgs):
    """
    Arguments:
     - convert_ks: temporary file for converting
     - xmlfile: group.xml from 'package-groups'
     - groups: Group list from original ks file
     - extra_pkgs: ExtraPackages and RemovePackages from original ks file

    Function:
     - convert group name to rpm list and write to ks file
       getting from xmlfile has group information.

    Return value:
     - True: success
     - False: fail caused by KeyError
    """
    xmltree = etree.parse(xmlfile)
    root = xmltree.getroot()
    group_info = dict()

    for group in root:
        pkg_list = list()
        for pkgname in group.find('packagelist').findall('packagereq'):
            pkg_list.append(pkgname.text)
        group_info[group.find('name').text] = pkg_list

    for group in groups:
        try:
            convert_ks.write('# @ ' + group + '\n')
            for pkg in sorted(group_info[group]):
                convert_ks.write(pkg + '\n')
        except KeyError:
            print '\nin convert_ks.py: '
            print 'error: Could not find @ ' + group + ' in package-groups\n'
            return False

    convert_ks.write('# Others\n')
    for pkg in extra_pkgs:
        convert_ks.write(pkg + '\n')

    return True

def main(origin_file, group_file):
    """
    Arguments:
     - origin_file: *.ks file wrote by Groups name
     - group_file: group.xml from 'package-groups'

    Function:
     - Read origin ks file and write to temp file line by line.
       In pkg group session, call write_package() to convert
       group name to rpm file list.
    """
    origin_ks = file(origin_file, 'r')
    (file_flag, convert_file) = tempfile.mkstemp()
    convert_ks = file(convert_file, 'w') #temporary file for converting
    groups = list()
    extra_pkgs = list()

    pkg_session = False
    for line in origin_ks.readlines():
        line_plaintext = line.strip()
        if not pkg_session and line_plaintext == "%packages":
            convert_ks.write(line + '\n')
            pkg_session = True
        elif pkg_session and line_plaintext == "%end":
            # write_package writes packages' list when pkg_session ends
            if not write_package(convert_ks, group_file, groups, extra_pkgs):
                # KeyError in write_package: close files and exit with error
                origin_ks.close()
                convert_ks.close()
                exit(1)
            convert_ks.write('\n')
            pkg_session = False

        if pkg_session:
            if line_plaintext.startswith('@'): # Read Group
                groups.append(line_plaintext[1:])
            elif not line_plaintext.startswith('%'): # Read Extra/RemovePackage
                extra_pkgs.append(line_plaintext)
        else:
            convert_ks.write(line)

    origin_ks.close()
    convert_ks.close()

    shutil.move(convert_file, origin_file)

if __name__ == '__main__':
    parser = argparse.ArgumentParser(
            description='''
                    Replace group names with list of packages they contain.
                   ''',
                    )
    parser.add_argument('ksfilename', type=str, help='ks file to modify')
    parser.add_argument('pkggroup', type=str,
                   help='group.xml file from package-groups package')
    args = parser.parse_args()

    main(args.ksfilename, args.pkggroup)