#!/usr/bin/python

import rpm
import glob
import os.path
import cpio
import lzma
import re

_ts = rpm.ts()
_ts.setVSFlags(0x7FFFFFFF)

tags = {}
for name in dir(rpm):
    if name.startswith("RPMTAG_"):
        tags[getattr(rpm, name)] = name[7:]

def read_menu_entry(filename, content):
    print filename
    m = re.search("Categories=(.+);\n", content)
    if m:
        categories = m.group(1).split(";")
        print categories

def write_desktop_file(directory, hdr, cpioarchive):
    path = os.path.join(directory, hdr["name"])
    if not os.path.exists(path):
        os.makedirs(path)
    f = open(os.path.join(path, os.path.basename(cpioarchive.filename)), "w")
    f.write(cpioarchive.read())
    f.close()


class LZMA:

    def __init__(self, f):
        self._f = f
        self.decomp = lzma.LZMADecompressor()
        self.leftover = ""

    def read(self, size):
        # highly inefficient
        while not size < len(self.leftover):
            c = self._f.read(size)
            if not c:
                break
            d = self.decomp.decompress(c)
            self.leftover += d
        result = self.leftover[:size]
        self.leftover = self.leftover[size:]
        return result

def read_package(path, targetpath):
    fd = os.open(path, os.O_RDONLY)
    hdr = _ts.hdrFromFdno(fd)

    fi = hdr.fiFromHeader()
    apps = []
    for (fname, size, mode, mtime, flags, dev, inode,
         nlink, state, vflags, user, group, digest) in fi:
        if fname.endswith(".desktop"):
            apps.append(fname)

    if not apps: 
        os.close(fd)
        return

    f = os.fdopen(fd)

    lf = LZMA(f)
    cpioarchive = cpio.CpioArchive(lf)

    for filename in cpioarchive:
        if filename.endswith(".desktop"):
            write_desktop_file(targetpath, hdr, cpioarchive)

    f.close()
    

def check_dir(rpmpath, targetpath):
    for f in glob.glob(os.path.join(rpmpath, "*.rpm")):
        read_package(f, targetpath)


check_dir("testrpms/", "desktopfiles/")