"""
Access windows credentials
"""

import ctypes as CT
import ctypes.wintypes as WT

CRED_TYPE_GENERIC = 0x01

LPBYTE = CT.POINTER(WT.BYTE)
LPTSTR = WT.LPSTR
LPCTSTR = WT.LPSTR
class CREDENTIAL_ATTRIBUTE(CT.Structure):
    _fields_ = [
        ('Keyword', LPTSTR),
        ('Flags', WT.DWORD),
        ('ValueSize', WT.DWORD),
        ('Value', LPBYTE)]
PCREDENTIAL_ATTRIBUTE = CT.POINTER(CREDENTIAL_ATTRIBUTE)
class CREDENTIAL(CT.Structure):
    _fields_ = [
        ('Flags', WT.DWORD),
        ('Type', WT.DWORD),
        ('TargetName', LPTSTR),
        ('Comment', LPTSTR),
        ('LastWritten', WT.FILETIME),
        ('CredentialBlobSize', WT.DWORD),
        ('CredentialBlob', LPBYTE),
        ('Persist', WT.DWORD),
        ('AttributeCount', WT.DWORD),
        ('Attributes', PCREDENTIAL_ATTRIBUTE),
        ('TargetAlias', LPTSTR),
        ('UserName', LPTSTR)]
PCREDENTIAL = CT.POINTER(CREDENTIAL)

advapi32 = CT.WinDLL('Advapi32.dll')
advapi32.CredReadA.restype = WT.BOOL
advapi32.CredReadA.argtypes = [LPCTSTR, WT.DWORD, WT.DWORD, CT.POINTER(PCREDENTIAL)]


def GetPassword(url):
    credPtr = PCREDENTIAL()
    if advapi32.CredReadA(url, CRED_TYPE_GENERIC, 0, CT.byref(credPtr)):
        username = credPtr.contents.UserName
        passwordSize = credPtr.contents.CredentialBlobSize
        unicodePassword = credPtr.contents.CredentialBlob[:passwordSize:2]
        password = ''.join(map(chr, unicodePassword))
        advapi32.CredFree(credPtr)
        return username, password
    else:
        raise IOError("Failure reading credential")