Rigify: refactor feature sets to avoid modifying global path.

Instead of adding the feature set installation directory
to the global path, and thus inserting the modules into
the top level namespace, add an empty rigify.feature_sets
package and use __path__ to redirect the module loader
to read its sub-modules from the feature set directory.

Now feature set modules are effectively installed into
that package and loaded as 'rigify.feature_sets.foo'.

As an aside, clean up loading code to avoid weird path
manipulations, add more safety checks when installing sets,
and add a way for sets to expose a user-friendly name.

1 files changed, 233 insertions, 0 deletions

diff --git a/rigify/feature_set_list.py b/rigify/feature_set_list.py
new file mode 100644
index 00000000..fb7075eb
--- /dev/null
+++ b/rigify/feature_set_list.py
@@ -0,0 +1,233 @@
+#====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#======================= END GPL LICENSE BLOCK ========================
+
+import bpy
+from bpy.props import StringProperty
+import os
+import re
+import importlib
+from zipfile import ZipFile
+from shutil import rmtree
+
+from . import feature_sets
+
+
+DEFAULT_NAME = 'rigify'
+
+INSTALL_PATH = feature_sets._install_path()
+NAME_PREFIX = feature_sets.__name__.split('.')
+
+
+def get_install_path(*, create=False):
+    if not os.path.exists(INSTALL_PATH):
+        if create:
+            os.makedirs(INSTALL_PATH, exist_ok=True)
+        else:
+            return None
+
+    return INSTALL_PATH
+
+
+def get_installed_list():
+    features_path = get_install_path()
+    if not features_path:
+        return []
+
+    sets = []
+
+    for fs in os.listdir(features_path):
+        if fs and fs[0] != '.' and fs != DEFAULT_NAME:
+            fs_path = os.path.join(features_path, fs)
+            if os.path.isdir(fs_path):
+                sets.append(fs)
+
+    return sets
+
+
+def get_module(feature_set):
+    return importlib.import_module('.'.join([*NAME_PREFIX, feature_set]))
+
+
+def get_module_safe(feature_set):
+    try:
+        return get_module(feature_set)
+    except:
+        return None
+
+
+def get_dir_path(feature_set, *extra_items):
+    base_dir = os.path.join(INSTALL_PATH, feature_set, *extra_items)
+    base_path = [*NAME_PREFIX, feature_set, *extra_items]
+    return base_dir, base_path
+
+
+def get_info_dict(feature_set):
+    module = get_module_safe(feature_set)
+
+    if module and hasattr(module, 'rigify_info'):
+        data = module.rigify_info
+        if isinstance(data, dict):
+            return data
+
+    return {}
+
+
+def get_ui_name(feature_set):
+    # Try to get user-defined name
+    info = get_info_dict(feature_set)
+    if 'name' in info:
+        return info['name']
+
+    # Default name based on directory
+    name = re.sub(r'[_.-]', ' ', feature_set)
+    name = re.sub(r'(?<=\d) (?=\d)', '.', name)
+    return name.title()
+
+
+def feature_set_items(scene, context):
+    """Get items for the Feature Set EnumProperty"""
+    items = [('all',)*3, ('rigify',)*3, ]
+
+    for fs in get_installed_list():
+        items.append((fs,)*3)
+
+    return items
+
+
+def verify_feature_set_archive(zipfile):
+    """Verify that the zip file contains one root directory, and some required files."""
+    dirname = None
+    init_found = False
+    data_found = False
+
+    for name in zipfile.namelist():
+        parts = re.split(r'[/\\]', name)
+
+        if dirname is None:
+            dirname = parts[0]
+        elif dirname != parts[0]:
+            dirname = None
+            break
+
+        if len(parts) == 2 and parts[1] == '__init__.py':
+            init_found = True
+
+        if len(parts) > 2 and parts[1] in {'rigs', 'metarigs'} and parts[-1] == '__init__.py':
+            data_found = True
+
+    return dirname, init_found, data_found
+
+
+class DATA_OT_rigify_add_feature_set(bpy.types.Operator):
+    bl_idname = "wm.rigify_add_feature_set"
+    bl_label = "Add External Feature Set"
+    bl_description = "Add external feature set (rigs, metarigs, ui templates)"
+    bl_options = {"REGISTER", "UNDO", "INTERNAL"}
+
+    filter_glob: StringProperty(default="*.zip", options={'HIDDEN'})
+    filepath: StringProperty(maxlen=1024, subtype='FILE_PATH', options={'HIDDEN', 'SKIP_SAVE'})
+
+    @classmethod
+    def poll(cls, context):
+        return True
+
+    def invoke(self, context, event):
+        context.window_manager.fileselect_add(self)
+        return {'RUNNING_MODAL'}
+
+    def execute(self, context):
+        addon_prefs = context.preferences.addons[__package__].preferences
+
+        rigify_config_path = get_install_path(create=True)
+
+        with ZipFile(bpy.path.abspath(self.filepath), 'r') as zip_archive:
+            base_dirname, init_found, data_found = verify_feature_set_archive(zip_archive)
+
+            if not base_dirname:
+                self.report({'ERROR'}, "The feature set archive must contain one base directory.")
+                return {'CANCELLED'}
+
+            # Patch up some invalid characters to allow using 'Download ZIP' on GitHub.
+            fixed_dirname = re.sub(r'[.-]', '_', base_dirname)
+
+            if not re.fullmatch(r'[a-zA-Z][a-zA-Z_0-9]*', fixed_dirname):
+                self.report({'ERROR'}, "The feature set archive base directory name is not a valid identifier: '%s'." % (base_dirname))
+                return {'CANCELLED'}
+
+            if fixed_dirname == DEFAULT_NAME:
+                self.report({'ERROR'}, "The '%s' name is not allowed for feature sets." % (DEFAULT_NAME))
+                return {'CANCELLED'}
+
+            if not init_found or not data_found:
+                self.report({'ERROR'}, "The feature set archive has no rigs or metarigs, or is missing __init__.py.")
+                return {'CANCELLED'}
+
+            base_dir = os.path.join(rigify_config_path, base_dirname)
+            fixed_dir = os.path.join(rigify_config_path, fixed_dirname)
+
+            for path, name in [(base_dir, base_dirname), (fixed_dir, fixed_dirname)]:
+                if os.path.exists(path):
+                    self.report({'ERROR'}, "Feature set directory already exists: '%s'." % (name))
+                    return {'CANCELLED'}
+
+            # Unpack the validated archive and fix the directory name if necessary
+            zip_archive.extractall(rigify_config_path)
+
+            if base_dir != fixed_dir:
+                os.rename(base_dir, fixed_dir)
+
+        addon_prefs.machin = bpy.props.EnumProperty(items=(('a',)*3, ('b',)*3, ('c',)*3),)
+
+        addon_prefs.update_external_rigs()
+        return {'FINISHED'}
+
+
+class DATA_OT_rigify_remove_feature_set(bpy.types.Operator):
+    bl_idname = "wm.rigify_remove_feature_set"
+    bl_label = "Remove External Feature Set"
+    bl_description = "Remove external feature set (rigs, metarigs, ui templates)"
+    bl_options = {"REGISTER", "UNDO", "INTERNAL"}
+
+    featureset: StringProperty(maxlen=1024, options={'HIDDEN', 'SKIP_SAVE'})
+
+    @classmethod
+    def poll(cls, context):
+        return True
+
+    def invoke(self, context, event):
+        return context.window_manager.invoke_confirm(self, event)
+
+    def execute(self, context):
+        addon_prefs = context.preferences.addons[__package__].preferences
+
+        rigify_config_path = get_install_path()
+        if rigify_config_path:
+            set_path = os.path.join(rigify_config_path, self.featureset)
+            if os.path.exists(set_path):
+                rmtree(set_path)
+
+        addon_prefs.update_external_rigs()
+        return {'FINISHED'}
+
+def register():
+    bpy.utils.register_class(DATA_OT_rigify_add_feature_set)
+    bpy.utils.register_class(DATA_OT_rigify_remove_feature_set)
+
+def unregister():
+    bpy.utils.unregister_class(DATA_OT_rigify_add_feature_set)
+    bpy.utils.unregister_class(DATA_OT_rigify_remove_feature_set)