[cli/utils] Open CMD when exe is double-clicked (#436)

This opens up CMD if
- the exe file was double-clicked
- no arguments are provided
- we're on Windows

legendary/cli.py

@@ -28,6 +28,7 @@ from legendary.utils.env import is_windows_mac_or_pyi
 from legendary.utils.eos import add_registry_entries, query_registry_entries, remove_registry_entries
 from legendary.utils.lfs import validate_files, clean_filename
 from legendary.utils.selective_dl import get_sdl_appname
+from legendary.utils.windows_helpers import double_clicked
 from legendary.utils.wine_helpers import read_registry, get_shell_folders
 
 # todo custom formatter for cli logger (clean info, highlighted error/warning)
@@ -2903,6 +2904,10 @@ def main():
                     continue
                 print(f'\nCommand: {choice}')
                 print(subparser.format_help())
+        elif os.name == 'nt' and double_clicked():
+            print('Please note that this is not the intended way to run Legendary.')
+            print('Follow https://github.com/derrod/legendary/wiki/Setup-Instructions to set it up properly')
+            subprocess.Popen(['cmd', '/K', 'echo>nul'])
         return
 
     cli = LegendaryCLI(override_config=args.config_file, api_timeout=args.api_timeout)

legendary/utils/windows_helpers.py

@@ -1,5 +1,6 @@
 import logging
 import winreg
+import ctypes
 
 _logger = logging.getLogger('WindowsHelpers')
 
@@ -80,3 +81,16 @@ def set_registry_value(hive, key, value, data, reg_type=winreg.REG_SZ, use_32bit
         except Exception as e:
             _logger.debug(f'Setting "{key}":"{value}" to "{data}" failed with {repr(e)}')
         winreg.CloseKey(k)
+
+
+def double_clicked() -> bool:
+    # Thanks https://stackoverflow.com/a/55476145
+
+    # Load kernel32.dll
+    kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)
+    # Create an array to store the processes in.  This doesn't actually need to
+    # be large enough to store the whole process list since GetConsoleProcessList()
+    # just returns the number of processes if the array is too small.
+    process_array = (ctypes.c_uint * 1)()
+    num_processes = kernel32.GetConsoleProcessList(process_array, 1)
+    return num_processes < 3