# vi:ts=4:sw=4:et

import ctypes
from ctypes.com import STDMETHOD
from ctypes.com.storage import IStream

_rapi = ctypes.windll.rapi


###########################################################
#
# Internal helpers
#

_DWORD = ctypes.c_ulong
_WCHAR = ctypes.c_wchar
_BOOL = ctypes.c_int

def _SUCCEEDED(hr):
    return hr >= 0

def _FAILED(hr):
    return hr < 0


###########################################################
#
# Error handling
#

CeRapiGetError = _rapi.CeRapiGetError
CeRapiGetError.argtypes = []
CeRapiGetError.restype = _DWORD # really a HRESULT

CeGetLastError = _rapi.CeGetLastError
CeGetLastError.argtypes = []
CeGetLastError.restype = _DWORD

class RapiError(Exception):
    """This error is raised by some functions in this module when an error occurs"""

    def __init__(self, message):
        self.rapi_errno = CeRapiGetError()
        self.ce_errno = CeGetLastError()
        if self.rapi_errno == 0:
            if self.ce_errno == 0:
                msg = message + " (No error code)"
            else:
                msg = "%s (CeGetLastError: %d)" % (message, self.ce_errno)
        else:
            msg = "%s (CeRapiGetError: %d)" % (message, self.rapi_errno)
        Exception.__init__(self, msg)


###########################################################
#
# Initialisation
#

class RAPIINIT(ctypes.Structure):
    _fields_ = [
        ("cbSize", _DWORD),
        ("heRapiInit", _DWORD),
        ("hrRapiInit", ctypes.HRESULT),
        ]

    def __init__(self):
        self.cbSize = ctypes.sizeof(self)


CeRapiInitEx = _rapi.CeRapiInitEx
CeRapiInitEx.argtypes = [ ctypes.POINTER(RAPIINIT) ]
CeRapiInitEx.restype = ctypes.HRESULT

CeRapiUninit = _rapi.CeRapiUninit
CeRapiUninit.argtypes = []
CeRapiUninit.restype = ctypes.HRESULT

def CeRapiInitTimeout(timeout_ms = 5000):
    """Initialises the RAPI connection, failing if it does not succeed within the specified timeout (milliseconds).
    Implemented by calling CeRapiInitEx, then waiting on the returned event handle with a timeout.
    Raises RapiError on failure.
    """
    ri = RAPIINIT()
    CeRapiInitEx(ctypes.byref(ri))
    # FIXME: how do you get the address of a ctypes.Structure field?
    hEvent = _DWORD(ri.heRapiInit)
    WAIT_OBJECT_0 = 0
    rwait = ctypes.windll.user32.MsgWaitForMultipleObjects(1, ctypes.byref(hEvent), 0, timeout_ms, 0)
    if rwait == WAIT_OBJECT_0:
        if _FAILED(ri.hrRapiInit):
            raise RapiError("CeRapiInitEx failed: " + str(ri.hrRapiInit))
        # else success
    else:
        # The wait timed out or failed
        ex = RapiError("Timeout waiting for CeRapiInitEx")
        CeRapiUninit()
        raise ex


###########################################################
#
# File I/O
#

INVALID_HANDLE_VALUE = 0xffffffff   # HANDLE is an unsigned long
ERROR_NO_MORE_FILES = 18
MAX_PATH = 260

class HANDLE(ctypes.c_ulong):
    def _check_HANDLE(handle):
        if handle == INVALID_HANDLE_VALUE:
            raise RapiError("RAPI call returned invalid handle")
        return handle

    _check_retval_ = staticmethod(_check_HANDLE)

class BOOLRESULT(ctypes.c_int):
    def _check_BOOLRESULT(value):
        if not value:
            raise RapiError("RAPI call returned FALSE")
        return value

    _check_retval_ = staticmethod(_check_BOOLRESULT)

class FILETIME(ctypes.Structure):
    _fields_ = [
        ("dwLowDateTime", _DWORD),
        ("dwHighDateTime", _DWORD),
        ]

class CE_FIND_DATA(ctypes.Structure):
    _fields_ = [
        ("dwFileAttributes", _DWORD),
        ("ftCreationTime", FILETIME),
        ("ftLastAccessTime", FILETIME),
        ("ftLastWriteTime", FILETIME),
        ("nFileSizeHigh", _DWORD),
        ("nFileSizeLow", _DWORD),
        ("dwOID", _DWORD),
        ("cFileName", _WCHAR * MAX_PATH),
        ]

    _as_parameter_ = property(ctypes.byref) # always passed by reference

CeFindFirstFile = _rapi.CeFindFirstFile
CeFindFirstFile.argtypes = [ ctypes.c_wchar_p, CE_FIND_DATA ]
CeFindFirstFile.restype = HANDLE

CeFindNextFile = _rapi.CeFindNextFile
CeFindNextFile.argtypes = [ HANDLE, CE_FIND_DATA ]

CeFindClose = _rapi.CeFindClose # TODO: check for errors?
CeFindClose.argtypes = [ HANDLE ]

CeCopyFile = _rapi.CeCopyFile
CeCopyFile.argtypes = [ ctypes.c_wchar_p, ctypes.c_wchar_p, _BOOL ]

CeDeleteFile = _rapi.CeDeleteFile
CeDeleteFile.argtypes = [ ctypes.c_wchar_p ]
CeDeleteFile.restype = BOOLRESULT

def listdir(path):
    """This function is meant to emulate os.listdir but lists files on the WinCE device"""
    pattern = unicode(path)
    if pattern[-1:] != u'\\':
        pattern += u'\\'
    pattern += u'*'
    lst = []
    data = CE_FIND_DATA()
    try:
        hFind = CeFindFirstFile(pattern, data)
    except RapiError, ex:
        # A "no files" error is perfectly normal
        if ex.ce_errno == ERROR_NO_MORE_FILES:
            return lst
        raise
    try:
        lst.append(data.cFileName)
        while CeFindNextFile(hFind, data):
            lst.append(data.cFileName)
    finally:
        CeFindClose(hFind)
    return lst


###########################################################
#
# Miscellaneous
#

CeCloseHandle = _rapi.CeCloseHandle # TODO: check for errors?
CeCloseHandle.argtypes = [ HANDLE ]

RAPISTREAMFLAG = ctypes.c_int   # enum
STREAM_TIMEOUT_READ = 0

class IRAPIStream(IStream):
    #_iid_ = ?
    _methods_ = IStream._methods_ + [
        STDMETHOD(ctypes.HRESULT, "SetRapiStat", RAPISTREAMFLAG, _DWORD),
        STDMETHOD(ctypes.HRESULT, "GetRapiStat", RAPISTREAMFLAG, ctypes.POINTER(_DWORD)),
    ]

CeRapiInvoke = _rapi.CeRapiInvoke
CeRapiInvoke.argtypes = [ ctypes.c_wchar_p, ctypes.c_wchar_p,
    _DWORD, ctypes.c_void_p, ctypes.POINTER(_DWORD), ctypes.POINTER(ctypes.c_void_p),
    ctypes.POINTER(ctypes.POINTER(IRAPIStream)), _DWORD ]
CeRapiInvoke.restype = ctypes.HRESULT

LocalFree = ctypes.windll.kernel32.LocalFree
LocalFree.argtypes = [ ctypes.c_void_p ]

class PROCESS_INFORMATION(ctypes.Structure):
    _fields_ = [
        ("hProcess", HANDLE),
        ("hThread", HANDLE),
        ("dwProcessId", _DWORD),
        ("dwThreadId", _DWORD),
        ]

    _as_parameter_ = property(ctypes.byref) # always passed by reference

CeCreateProcess = _rapi.CeCreateProcess
CeCreateProcess.argtypes = [ ctypes.c_wchar_p, ctypes.c_wchar_p, ctypes.c_void_p,
    ctypes.c_void_p, _BOOL, _DWORD, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p,
    PROCESS_INFORMATION ]
CeCreateProcess.restype = BOOLRESULT

def RunProcess(program, command_line, flags=0):
    if command_line:
        command_line = unicode(command_line)
    else:
        command_line = None
    pi = PROCESS_INFORMATION()
    CeCreateProcess(unicode(program), command_line,
            None, None, 0, 0, None, None, None, pi)
    CeCloseHandle(pi.hProcess)
    CeCloseHandle(pi.hThread)
    return pi.dwProcessId


###########################################################
#
# Testing
#

def test():
    ri = RAPIINIT()
    print "Calling CeRapiInitEx"
    CeRapiInitEx(ctypes.byref(ri))
    print "CeRapiInitEx started..."
    # FIXME: how do you get the address of a ctypes.Structure field?
    hEvent = _DWORD(ri.heRapiInit)
    WAIT_OBJECT_0 = 0
    rwait = ctypes.windll.user32.MsgWaitForMultipleObjects(1, ctypes.byref(hEvent), 0, 5000, 0)
    if rwait == WAIT_OBJECT_0:
        if _SUCCEEDED(ri.hrRapiInit):
            print "CeRapiInitEx finished successfully"
        else:
            print "CeRapiInitEx failed: ", ri.hrRapiInit
            return
    else:
        print "CeRapiInitEx timed out: calling CeRapiUninit"
        CeRapiUninit()
        return
    # Init success
    # Clean up
    print "Calling CeRapiUninit"
    CeRapiUninit()

if __name__ == '__main__':
    test()