# Copyright (C) 2006, 2007 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Win32-specific helper functions

Only one dependency: ctypes should be installed.
"""

import os
import struct
import sys


# Windows version
if sys.platform == 'win32':
    _major,_minor,_build,_platform,_text = sys.getwindowsversion()
    # from MSDN:
    # dwPlatformId
    #   The operating system platform.
    #   This member can be one of the following values.
    #   ==========================  ======================================
    #   Value                       Meaning
    #   --------------------------  --------------------------------------
    #   VER_PLATFORM_WIN32_NT       The operating system is Windows Vista,
    #   2                           Windows Server "Longhorn",
    #                               Windows Server 2003, Windows XP,
    #                               Windows 2000, or Windows NT.
    #
    #   VER_PLATFORM_WIN32_WINDOWS  The operating system is Windows Me,
    #   1                           Windows 98, or Windows 95.
    #   ==========================  ======================================
    if _platform == 2:
        winver = 'Windows NT'
    else:
        # don't care about real Windows name, just to force safe operations
        winver = 'Windows 98'
else:
    winver = None


# We can cope without it; use a separate variable to help pyflakes
try:
    import ctypes
    has_ctypes = True
except ImportError:
    has_ctypes = False
else:
    if winver == 'Windows 98':
        create_buffer = ctypes.create_string_buffer
        suffix = 'A'
    else:
        create_buffer = ctypes.create_unicode_buffer
        suffix = 'W'
try:
    import win32file
    has_win32file = True
except ImportError:
    has_win32file = False
try:
    import win32api
    has_win32api = True
except ImportError:
    has_win32api = False

# pulling in win32com.shell is a bit of overhead, and normally we don't need
# it as ctypes is preferred and common.  lazy_imports and "optional"
# modules don't work well, so we do our own lazy thing...
has_win32com_shell = None # Set to True or False once we know for sure...

# Special Win32 API constants
# Handles of std streams
WIN32_STDIN_HANDLE = -10
WIN32_STDOUT_HANDLE = -11
WIN32_STDERR_HANDLE = -12

# CSIDL constants (from MSDN 2003)
CSIDL_APPDATA = 0x001A      # Application Data folder
CSIDL_LOCAL_APPDATA = 0x001c# <user name>\Local Settings\Application Data (non roaming)
CSIDL_PERSONAL = 0x0005     # My Documents folder

# from winapi C headers
MAX_PATH = 260
UNLEN = 256
MAX_COMPUTERNAME_LENGTH = 31


def debug_memory_win32api(message='', short=True):
    """Use trace.note() to dump the running memory info."""
    from bzrlib import trace
    if has_ctypes:
        class PROCESS_MEMORY_COUNTERS_EX(ctypes.Structure):
            """Used by GetProcessMemoryInfo"""
            _fields_ = [('cb', ctypes.c_ulong),
                        ('PageFaultCount', ctypes.c_ulong),
                        ('PeakWorkingSetSize', ctypes.c_size_t),
                        ('WorkingSetSize', ctypes.c_size_t),
                        ('QuotaPeakPagedPoolUsage', ctypes.c_size_t),
                        ('QuotaPagedPoolUsage', ctypes.c_size_t),
                        ('QuotaPeakNonPagedPoolUsage', ctypes.c_size_t),
                        ('QuotaNonPagedPoolUsage', ctypes.c_size_t),
                        ('PagefileUsage', ctypes.c_size_t),
                        ('PeakPagefileUsage', ctypes.c_size_t),
                        ('PrivateUsage', ctypes.c_size_t),
                       ]
        cur_process = ctypes.windll.kernel32.GetCurrentProcess()
        mem_struct = PROCESS_MEMORY_COUNTERS_EX()
        ret = ctypes.windll.psapi.GetProcessMemoryInfo(cur_process,
            ctypes.byref(mem_struct),
            ctypes.sizeof(mem_struct))
        if not ret:
            trace.note('Failed to GetProcessMemoryInfo()')
            return
        info = {'PageFaultCount': mem_struct.PageFaultCount,
                'PeakWorkingSetSize': mem_struct.PeakWorkingSetSize,
                'WorkingSetSize': mem_struct.WorkingSetSize,
                'QuotaPeakPagedPoolUsage': mem_struct.QuotaPeakPagedPoolUsage,
                'QuotaPagedPoolUsage': mem_struct.QuotaPagedPoolUsage,
                'QuotaPeakNonPagedPoolUsage': mem_struct.QuotaPeakNonPagedPoolUsage,
                'QuotaNonPagedPoolUsage': mem_struct.QuotaNonPagedPoolUsage,
                'PagefileUsage': mem_struct.PagefileUsage,
                'PeakPagefileUsage': mem_struct.PeakPagefileUsage,
                'PrivateUsage': mem_struct.PrivateUsage,
               }
    elif has_win32api:
        import win32process
        # win32process does not return PrivateUsage, because it doesn't use
        # PROCESS_MEMORY_COUNTERS_EX (it uses the one without _EX).
        proc = win32process.GetCurrentProcess()
        info = win32process.GetProcessMemoryInfo(proc)
    else:
        trace.note('Cannot debug memory on win32 without ctypes'
                   ' or win32process')
        return
    trace.note('WorkingSize       %8d kB', info['WorkingSetSize'] / 1024)
    trace.note('PeakWorking       %8d kB', info['PeakWorkingSetSize'] / 1024)
    if short:
        return
    trace.note('PagefileUsage     %8d kB', info.get('PagefileUsage', 0) / 1024)
    trace.note('PeakPagefileUsage %8d kB', info.get('PeakPagefileUsage', 0) / 1024)
    trace.note('PrivateUsage      %8d kB', info.get('PrivateUsage', 0) / 1024)
    trace.note('PageFaultCount    %8d', info.get('PageFaultCount', 0))


def get_console_size(defaultx=80, defaulty=25):
    """Return size of current console.

    This function try to determine actual size of current working
    console window and return tuple (sizex, sizey) if success,
    or default size (defaultx, defaulty) otherwise.
    """
    if not has_ctypes:
        # no ctypes is found
        return (defaultx, defaulty)

    # To avoid problem with redirecting output via pipe
    # need to use stderr instead of stdout
    h = ctypes.windll.kernel32.GetStdHandle(WIN32_STDERR_HANDLE)
    csbi = ctypes.create_string_buffer(22)
    res = ctypes.windll.kernel32.GetConsoleScreenBufferInfo(h, csbi)

    if res:
        (bufx, bufy, curx, cury, wattr,
        left, top, right, bottom, maxx, maxy) = struct.unpack("hhhhHhhhhhh", csbi.raw)
        sizex = right - left + 1
        sizey = bottom - top + 1
        return (sizex, sizey)
    else:
        return (defaultx, defaulty)


def _get_sh_special_folder_path(csidl):
    """Call SHGetSpecialFolderPathW if available, or return None.

    Result is always unicode (or None).
    """
    if has_ctypes:
        try:
            SHGetSpecialFolderPath = \
                ctypes.windll.shell32.SHGetSpecialFolderPathW
        except AttributeError:
            pass
        else:
            buf = ctypes.create_unicode_buffer(MAX_PATH)
            if SHGetSpecialFolderPath(None,buf,csidl,0):
                return buf.value

    global has_win32com_shell
    if has_win32com_shell is None:
        try:
            from win32com.shell import shell
            has_win32com_shell = True
        except ImportError:
            has_win32com_shell = False
    if has_win32com_shell:
        # still need to bind the name locally, but this is fast.
        from win32com.shell import shell
        try:
            return shell.SHGetSpecialFolderPath(0, csidl, 0)
        except shell.error:
            # possibly E_NOTIMPL meaning we can't load the function pointer,
            # or E_FAIL meaning the function failed - regardless, just ignore it
            pass
    return None


def get_appdata_location():
    """Return Application Data location.
    Return None if we cannot obtain location.

    Windows defines two 'Application Data' folders per user - a 'roaming'
    one that moves with the user as they logon to different machines, and
    a 'local' one that stays local to the machine.  This returns the 'roaming'
    directory, and thus is suitable for storing user-preferences, etc.

    Returned value can be unicode or plain string.
    To convert plain string to unicode use
    s.decode(osutils.get_user_encoding())
    (XXX - but see bug 262874, which asserts the correct encoding is 'mbcs')
    """
    appdata = _get_sh_special_folder_path(CSIDL_APPDATA)
    if appdata:
        return appdata
    # from env variable
    appdata = os.environ.get('APPDATA')
    if appdata:
        return appdata
    # if we fall to this point we on win98
    # at least try C:/WINDOWS/Application Data
    windir = os.environ.get('windir')
    if windir:
        appdata = os.path.join(windir, 'Application Data')
        if os.path.isdir(appdata):
            return appdata
    # did not find anything
    return None


def get_local_appdata_location():
    """Return Local Application Data location.
    Return the same as get_appdata_location() if we cannot obtain location.

    Windows defines two 'Application Data' folders per user - a 'roaming'
    one that moves with the user as they logon to different machines, and
    a 'local' one that stays local to the machine.  This returns the 'local'
    directory, and thus is suitable for caches, temp files and other things
    which don't need to move with the user.

    Returned value can be unicode or plain string.
    To convert plain string to unicode use
    s.decode(bzrlib.user_encoding)
    (XXX - but see bug 262874, which asserts the correct encoding is 'mbcs')
    """
    local = _get_sh_special_folder_path(CSIDL_LOCAL_APPDATA)
    if local:
        return local
    # Vista supplies LOCALAPPDATA, but XP and earlier do not.
    local = os.environ.get('LOCALAPPDATA')
    if local:
        return local
    return get_appdata_location()


def get_home_location():
    """Return user's home location.
    Assume on win32 it's the <My Documents> folder.
    If location cannot be obtained return system drive root,
    i.e. C:\

    Returned value can be unicode or plain sring.
    To convert plain string to unicode use
    s.decode(osutils.get_user_encoding())
    """
    home = _get_sh_special_folder_path(CSIDL_PERSONAL)
    if home:
        return home
    # try for HOME env variable
    home = os.path.expanduser('~')
    if home != '~':
        return home
    # at least return windows root directory
    windir = os.environ.get('windir')
    if windir:
        return os.path.splitdrive(windir)[0] + '/'
    # otherwise C:\ is good enough for 98% users
    return 'C:/'


def get_user_name():
    """Return user name as login name.
    If name cannot be obtained return None.

    Returned value can be unicode or plain sring.
    To convert plain string to unicode use
    s.decode(osutils.get_user_encoding())
    """
    if has_ctypes:
        try:
            advapi32 = ctypes.windll.advapi32
            GetUserName = getattr(advapi32, 'GetUserName'+suffix)
        except AttributeError:
            pass
        else:
            buf = create_buffer(UNLEN+1)
            n = ctypes.c_int(UNLEN+1)
            if GetUserName(buf, ctypes.byref(n)):
                return buf.value
    # otherwise try env variables
    return os.environ.get('USERNAME', None)


# 1 == ComputerNameDnsHostname, which returns "The DNS host name of the local
# computer or the cluster associated with the local computer."
_WIN32_ComputerNameDnsHostname = 1

def get_host_name():
    """Return host machine name.
    If name cannot be obtained return None.

    :return: A unicode string representing the host name. On win98, this may be
        a plain string as win32 api doesn't support unicode.
    """
    if has_win32api:
        try:
            return win32api.GetComputerNameEx(_WIN32_ComputerNameDnsHostname)
        except (NotImplementedError, win32api.error):
            # NotImplemented will happen on win9x...
            pass
    if has_ctypes:
        try:
            kernel32 = ctypes.windll.kernel32
        except AttributeError:
            pass # Missing the module we need
        else:
            buf = create_buffer(MAX_COMPUTERNAME_LENGTH+1)
            n = ctypes.c_int(MAX_COMPUTERNAME_LENGTH+1)

            # Try GetComputerNameEx which gives a proper Unicode hostname
            GetComputerNameEx = getattr(kernel32, 'GetComputerNameEx'+suffix,
                                        None)
            if (GetComputerNameEx is not None
                and GetComputerNameEx(_WIN32_ComputerNameDnsHostname,
                                      buf, ctypes.byref(n))):
                return buf.value

            # Try GetComputerName in case GetComputerNameEx wasn't found
            # It returns the NETBIOS name, which isn't as good, but still ok.
            # The first GetComputerNameEx might have changed 'n', so reset it
            n = ctypes.c_int(MAX_COMPUTERNAME_LENGTH+1)
            GetComputerName = getattr(kernel32, 'GetComputerName'+suffix,
                                      None)
            if (GetComputerName is not None
                and GetComputerName(buf, ctypes.byref(n))):
                return buf.value
    # otherwise try env variables, which will be 'mbcs' encoded
    # on Windows (Python doesn't expose the native win32 unicode environment)
    # According to this:
    # http://msdn.microsoft.com/en-us/library/aa246807.aspx
    # environment variables should always be encoded in 'mbcs'.
    try:
        return os.environ['COMPUTERNAME'].decode("mbcs")
    except KeyError:
        return None


def _ensure_unicode(s):
    from bzrlib import osutils
    if s and type(s) != unicode:
        from bzrlib import osutils
        s = s.decode(osutils.get_user_encoding())
    return s


def get_appdata_location_unicode():
    return _ensure_unicode(get_appdata_location())

def get_home_location_unicode():
    return _ensure_unicode(get_home_location())

def get_user_name_unicode():
    return _ensure_unicode(get_user_name())

def get_host_name_unicode():
    return _ensure_unicode(get_host_name())


def _ensure_with_dir(path):
    if not os.path.split(path)[0] or path.startswith(u'*') or path.startswith(u'?'):
        return u'./' + path, True
    else:
        return path, False

def _undo_ensure_with_dir(path, corrected):
    if corrected:
        return path[2:]
    else:
        return path



def glob_expand(file_list):
    """Replacement for glob expansion by the shell.

    Win32's cmd.exe does not do glob expansion (eg ``*.py``), so we do our own
    here.

    :param file_list: A list of filenames which may include shell globs.
    :return: An expanded list of filenames.

    Introduced in bzrlib 0.18.
    """
    if not file_list:
        return []
    import glob
    expanded_file_list = []
    for possible_glob in file_list:

        # work around bugs in glob.glob()
        # - Python bug #1001604 ("glob doesn't return unicode with ...")
        # - failing expansion for */* with non-iso-8859-* chars
        possible_glob, corrected = _ensure_with_dir(possible_glob)
        glob_files = glob.glob(possible_glob)

        if glob_files == []:
            # special case to let the normal code path handle
            # files that do not exists
            expanded_file_list.append(
                _undo_ensure_with_dir(possible_glob, corrected))
        else:
            glob_files = [_undo_ensure_with_dir(elem, corrected) for elem in glob_files]
            expanded_file_list += glob_files

    return [elem.replace(u'\\', u'/') for elem in expanded_file_list]


def get_app_path(appname):
    """Look up in Windows registry for full path to application executable.
    Typicaly, applications create subkey with their basename
    in HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\

    :param  appname:    name of application (if no filename extension
                        is specified, .exe used)
    :return:    full path to aplication executable from registry,
                or appname itself if nothing found.
    """
    import _winreg
    try:
        hkey = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,
                               r'SOFTWARE\Microsoft\Windows'
                               r'\CurrentVersion\App Paths')
    except EnvironmentError:
        return appname

    basename = appname
    if not os.path.splitext(basename)[1]:
        basename = appname + '.exe'
    try:
        try:
            fullpath = _winreg.QueryValue(hkey, basename)
        except WindowsError:
            fullpath = appname
    finally:
        _winreg.CloseKey(hkey)

    return fullpath


def set_file_attr_hidden(path):
    """Set file attributes to hidden if possible"""
    if has_win32file:
        win32file.SetFileAttributes(path, win32file.FILE_ATTRIBUTE_HIDDEN)
