From 20096a88c8d120a1915831d38af063b147112319 Mon Sep 17 00:00:00 2001
From: Joe R <joeraz5@verizon.net>
Date: Wed, 15 Feb 2023 19:29:40 -0500
Subject: [PATCH] Documentation on plugins, and code to support multiple
 versions of plugin import module.

---
 html-src/gen-html.py           |  1 +
 html-src/index.html            |  1 +
 html-src/plugins.html          | 14 ++++++++++++++
 html-src/solitaire_wizard.html |  6 ++++--
 pysollib/gamedb.py             | 21 +++++++++++++++++----
 5 files changed, 37 insertions(+), 6 deletions(-)
 create mode 100644 html-src/plugins.html

diff --git a/html-src/gen-html.py b/html-src/gen-html.py
index ea965f4a..c979321f 100755
--- a/html-src/gen-html.py
+++ b/html-src/gen-html.py
@@ -64,6 +64,7 @@ files = [
     ('assist_options.html', 'PySol - Assist Options'),
     ('solitaire_wizard.html', 'PySol - Solitaire Wizard'),
     ('cardset_customization.html', 'PySol - Cardset Customization'),
+    ('plugins.html', 'PySol - Plugins'),
     ]
 
 rules_files = [
diff --git a/html-src/index.html b/html-src/index.html
index 8b0ce34c..c8909c92 100644
--- a/html-src/index.html
+++ b/html-src/index.html
@@ -16,6 +16,7 @@
 <li> <a href="assist_options.html">Assist Options</a>
 <li> <a href="solitaire_wizard.html">Solitaire Wizard</a>
 <li> <a href="cardset_customization.html">Cardset Customization</a>
+<li> <a href="plugins.html">Plugins</a>
 </ul>
 <h2>Misc</h2>
 <ul>
diff --git a/html-src/plugins.html b/html-src/plugins.html
new file mode 100644
index 00000000..45ad8277
--- /dev/null
+++ b/html-src/plugins.html
@@ -0,0 +1,14 @@
+<h1>Plugins</h1>
+<p>
+PySolFC can support adding additional games, or making other modifications
+by writing Python scripts that work as plugins.  These scripts can be added
+to the plugins folder of your user folder or the PySolFC installation directory.
+Plugins can be used to create and add games that are too complex for the
+<a href='solitaire_wizard.html'>Solitaire Wizard</a> options.
+<p>
+A couple sample plugins are available for download on the PySolFC website
+<a href='https://sourceforge.net/projects/pysolfc/files/Sample%20Plugins/'>here</a>.
+These plugins recreate a couple of PySol's more complex games, including
+<a href='rules/demonsandthieves.html'>Demons and Thieves</a> and
+<a href='rules/crossword.html'>Crossword</a> and can be used as a guide to
+help write your own plugins.
diff --git a/html-src/solitaire_wizard.html b/html-src/solitaire_wizard.html
index 97548055..7e527e6e 100644
--- a/html-src/solitaire_wizard.html
+++ b/html-src/solitaire_wizard.html
@@ -1,11 +1,13 @@
 <h1>Solitaire Wizard</h1>
 <p>
 The Solitaire Wizard is a feature in PySol that allows you to create and play
-custom solitaire games.
+custom solitaire games.  The Solitaire Wizard is an easy way to create custom
+games, though its options are a bit limited.  More complex games can be created
+with <a href='plugins.html'>plugins</a>.
 <p>
 Also note that the Solitaire Wizard may not be enabled in mobile versions of
 PySol.
-
+<p>
 Below are the different options you can set when using the Solitaire Wizard:
 
 <h2>General</h2>
diff --git a/pysollib/gamedb.py b/pysollib/gamedb.py
index e702973f..82ebb0ac 100644
--- a/pysollib/gamedb.py
+++ b/pysollib/gamedb.py
@@ -21,9 +21,6 @@
 #
 # ---------------------------------------------------------------------------##
 
-
-import imp
-
 import pysollib.settings
 from pysollib.mfxutil import Struct, print_err
 from pysollib.mygettext import _, n_
@@ -31,6 +28,16 @@ from pysollib.resource import CSI
 
 import six
 
+# Handle import of import library - different libraries are needed
+# for different Python versions.
+imp = None
+util = None
+try:
+    from importlib import util
+except ImportError:
+    util = None
+    import imp
+
 # ************************************************************************
 # * constants
 # ************************************************************************
@@ -862,6 +869,12 @@ def loadGame(modname, filename, check_game=False):
     # print "load game", modname, filename
     GAME_DB.check_game = check_game
     GAME_DB.current_filename = filename
-    imp.load_source(modname, filename)
+    if util is not None:
+        spec = util.spec_from_file_location(modname, filename)
+        module = util.module_from_spec(spec)
+        spec.loader.exec_module(module)
+    else:
+        imp.load_source(modname, filename)
+
     # execfile(filename, globals(), globals())
     GAME_DB.current_filename = None