Add support for ANSI colors on Windows

Windows Terminal is the Default in Windows 11, so there is no reason to
not support ANSI colors on Windows.

Explicitly disable ANSI colors on WASI, since ANSI escape characters are
disabled for security reasons.

codespell_lib/_codespell.py

@@ -18,11 +18,13 @@
 
 import argparse
 import configparser
+import ctypes
 import fnmatch
 import os
 import re
 import sys
 import textwrap
+from ctypes import wintypes
 from typing import Any, Dict, List, Match, Optional, Pattern, Sequence, Set, Tuple
 
 # autogenerated by setuptools_scm
@@ -120,6 +122,10 @@
 EX_DATAERR = 65
 EX_CONFIG = 78
 
+# Windows specific constants
+ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004
+STD_OUTPUT_HANDLE = wintypes.HANDLE(-11)
+
 # OPTIONS:
 #
 # ARGUMENTS:
@@ -308,21 +314,52 @@ def _toml_to_parseconfig(toml_dict: Dict[str, Any]) -> Dict[str, Any]:
     return {k: "" if v is True else v for k, v in toml_dict.items() if v is not False}
 
 
+def _supports_ansi_colors() -> bool:
+    if sys.platform == "win32":
+        # Windows Terminal enables ANSI escape codes by default. In other cases
+        # it is disabled.
+        # See https://ss64.com/nt/syntax-ansi.html for more information.
+        kernel32 = ctypes.WinDLL("kernel32")
+
+        # fmt: off
+        kernel32.GetConsoleMode.argtypes = (
+            wintypes.HANDLE,   # _In_  hConsoleHandle
+            wintypes.LPDWORD,  # _Out_ lpMode
+        )
+        # fmt: on
+        kernel32.GetConsoleMode.restype = wintypes.BOOL
+
+        mode = wintypes.DWORD()
+        handle = kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
+        if not kernel32.GetConsoleMode(handle, ctypes.byref(mode)):
+            # TODO: print a warning with the error message on stderr?
+            return False
+
+        return (mode.value & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0
+    elif sys.platform == "wasi":
+        # WASI disables ANSI escape codes for security reasons.
+        # See https://github.com/WebAssembly/WASI/issues/162.
+        return False
+    elif sys.stdout.isatty():
+        return True
+
+    return False
+
+
 def parse_options(
     args: Sequence[str],
 ) -> Tuple[argparse.Namespace, argparse.ArgumentParser, List[str]]:
     parser = argparse.ArgumentParser(formatter_class=NewlineHelpFormatter)
 
-    parser.set_defaults(colors=sys.stdout.isatty())
+    parser.set_defaults(colors=_supports_ansi_colors())
     parser.add_argument("--version", action="version", version=VERSION)
 
     parser.add_argument(
         "-d",
         "--disable-colors",
         action="store_false",
         dest="colors",
-        help="disable colors, even when printing to terminal "
-        "(always set for Windows)",
+        help="disable colors, even when printing to terminal",
     )
     parser.add_argument(
         "-c",
@@ -1130,7 +1167,7 @@ def main(*args: str) -> int:
     for dictionary in use_dictionaries:
         build_dict(dictionary, misspellings, ignore_words)
     colors = TermColors()
-    if not options.colors or sys.platform == "win32":
+    if not options.colors:
         colors.disable()
 
     if options.summary: