import _winreg

import re

from os import listdir

import ctypes



wallDir = 'c:\\wallpaper\\';

wallPaperLocation = ('Control Panel\\Desktop')

key = _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, wallPaperLocation, 0, _winreg.KEY_ALL_ACCESS)

files = []

for file in listdir(wallDir):

    g = re.match("^.+\.jpg$", file, re.IGNORECASE)

    if g:

        files.append(file) 



v = _winreg.QueryValueEx(key, 'WallPaper')

print v[0]

g = re.match("^.+\\\(.+)$", v[0])

oldname = ""

if g:

    oldname =  g.group(1)

else:

    print "No Match"

    sys.exit(1)



print oldname

print files



if len(files) > 0:



    #find idx of old name

    oidx = -1

    n = 0

    for file in files:

        if file == oldname:

            oidx = n

            break

        else:

            n += 1



    idx = 0

    if oidx >= 0:

        idx = (oidx + 1) % len(files)



    

    print "Setting"



    ctypes.windll.user32.SystemParametersInfoA(20, 0, wallDir + files[idx], 0)



    _winreg.SetValueEx(key, 'WallPaper', 0, _winreg.REG_SZ, wallDir + files[idx])

    _winreg.FlushKey(key)

    _winreg.CloseKey(key)