Initial IFileOperation for Windows

- Try using IFileOperation instead of SHFileOperation
  - Use pywin32 to accomplish this
  - Implement fallback when pywin32 not available
- Handles paths like `C:\` just fine bu the `\\?\` paths in the test
  cause issue
- Add batching for IFileOperation version (performance)
- Minor formatting applied by editor

send2trash/plat_win.py

@@ -5,23 +5,91 @@
 # http://www.hardcoded.net/licenses/bsd_license
 
 from __future__ import unicode_literals
-
-from ctypes import (windll, Structure, byref, c_uint,
-                    create_unicode_buffer, addressof,
-                    GetLastError, FormatError)
-from ctypes.wintypes import HWND, UINT, LPCWSTR, BOOL
 import os.path as op
-
 from .compat import text_type
 
-kernel32 = windll.kernel32
-GetShortPathNameW = kernel32.GetShortPathNameW
+try:
+    # Attempt to use pywin32 to use IFileOperation
+    import pythoncom
+    import pywintypes
+    from win32com.shell import shell, shellcon
+    from platform import version
 
-shell32 = windll.shell32
-SHFileOperationW = shell32.SHFileOperationW
+    def send2trash(path):
+        if not isinstance(path, list):
+            path = [path]
+        # convert data type
+        path = [
+            text_type(item, "mbcs") if not isinstance(item, text_type) else item
+            for item in path
+        ]
+        # convert to full paths
+        path = [op.abspath(item) if not op.isabs(item) else item for item in path]
+        # create instance of file operation object
+        fileop = pythoncom.CoCreateInstance(
+            shell.CLSID_FileOperation,
+            None,
+            pythoncom.CLSCTX_ALL,
+            shell.IID_IFileOperation,
+        )
+        # default flags to use
+        flags = (
+            shellcon.FOF_NOCONFIRMATION
+            | shellcon.FOF_NOERRORUI
+            | shellcon.FOF_SILENT
+            | shellcon.FOFX_EARLYFAILURE
+        )
+        # determine rest of the flags based on OS version
+        # use newer recommended flags if available
+        if int(version().split(".", 1)[0]) >= 8 and False:
+            flags |= (
+                0x20000000  # FOFX_ADDUNDORECORD win 8+
+                | 0x00080000  # FOFX_RECYCLEONDELETE win 8+
+            )
+        else:
+            flags |= shellcon.FOF_ALLOWUNDO
+        # set the flags
+        fileop.SetOperationFlags(flags)
+        # actually try to perform the operation, this section may throw a
+        # pywintypes.com_error which does not seem to create as nice of an
+        # error as OSError so wrapping with try to convert
+        try:
+            for itemPath in path:
+                item = shell.SHCreateItemFromParsingName(
+                    itemPath, None, shell.IID_IShellItem
+                )
+                fileop.DeleteItem(item)
+            result = fileop.PerformOperations()
+            aborted = fileop.GetAnyOperationsAborted()
+            # if non-zero result or aborted throw an exception
+            if result or aborted:
+                raise OSError(None, None, path, result)
+        except pywintypes.com_error as error:
+            # convert to standard OS error, allows other code to get a
+            # normal errno
+            raise OSError(None, error.strerror, path, error.hresult)
 
 
-class SHFILEOPSTRUCTW(Structure):
+except ImportError:
+    from ctypes import (
+        windll,
+        Structure,
+        byref,
+        c_uint,
+        create_unicode_buffer,
+        addressof,
+        GetLastError,
+        FormatError,
+    )
+    from ctypes.wintypes import HWND, UINT, LPCWSTR, BOOL
+
+    kernel32 = windll.kernel32
+    GetShortPathNameW = kernel32.GetShortPathNameW
+
+    shell32 = windll.shell32
+    SHFileOperationW = shell32.SHFileOperationW
+
+    class SHFILEOPSTRUCTW(Structure):
         _fields_ = [
             ("hwnd", HWND),
             ("wFunc", UINT),
@@ -33,22 +101,20 @@ class SHFILEOPSTRUCTW(Structure):
             ("lpszProgressTitle", LPCWSTR),
         ]
 
+    FO_MOVE = 1
+    FO_COPY = 2
+    FO_DELETE = 3
+    FO_RENAME = 4
 
-FO_MOVE = 1
-FO_COPY = 2
-FO_DELETE = 3
-FO_RENAME = 4
+    FOF_MULTIDESTFILES = 1
+    FOF_SILENT = 4
+    FOF_NOCONFIRMATION = 16
+    FOF_ALLOWUNDO = 64
+    FOF_NOERRORUI = 1024
 
-FOF_MULTIDESTFILES = 1
-FOF_SILENT = 4
-FOF_NOCONFIRMATION = 16
-FOF_ALLOWUNDO = 64
-FOF_NOERRORUI = 1024
-
-
-def get_short_path_name(long_name):
-    if not long_name.startswith('\\\\?\\'):
-        long_name = '\\\\?\\' + long_name
+    def get_short_path_name(long_name):
+        if not long_name.startswith("\\\\?\\"):
+            long_name = "\\\\?\\" + long_name
         buf_size = GetShortPathNameW(long_name, None, 0)
         # FIX: https://github.com/hsoft/send2trash/issues/31
         # If buffer size is zero, an error has occurred.
@@ -59,10 +125,9 @@ def get_short_path_name(long_name):
         GetShortPathNameW(long_name, output, buf_size)
         return output.value[4:]  # Remove '\\?\' for SHFileOperationW
 
-
-def send2trash(path):
+    def send2trash(path):
         if not isinstance(path, text_type):
-        path = text_type(path, 'mbcs')
+            path = text_type(path, "mbcs")
         if not op.isabs(path):
             path = op.abspath(path)
         path = get_short_path_name(path)
@@ -80,7 +145,7 @@ def send2trash(path):
         # NOTE: based on how python allocates memory for these types they should
         # always be zero, if this is ever not true we can go back to explicitly
         # setting the last two characters to null using buffer[index] = '\0'.
-    buffer = create_unicode_buffer(path, len(path)+2)
+        buffer = create_unicode_buffer(path, len(path) + 2)
         fileop.pFrom = LPCWSTR(addressof(buffer))
         fileop.pTo = None
         fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT