[automation] Add provider script extension

bundles/org.openhab.core.automation.module.script.rulesupport/src/main/java/org/openhab/core/automation/module/script/rulesupport/internal/ProviderScriptExtension.java

@@ -0,0 +1,99 @@
+/**
+ * Copyright (c) 2010-2024 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.module.script.rulesupport.internal;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.core.automation.module.script.ScriptExtensionProvider;
+import org.openhab.core.automation.module.script.rulesupport.shared.ScriptedItemProvider;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.ServiceRegistration;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+
+/**
+ * The {@link ProviderScriptExtension} provides types to support providing openHAB entities like items through scripts.
+ * It handles the registration and un-registration of the {@link org.openhab.core.common.registry.Provider} services.
+ *
+ * @author Florian Hotze - Initial contribution
+ */
+@Component(immediate = true)
+@NonNullByDefault
+public class ProviderScriptExtension implements ScriptExtensionProvider {
+    static final String PRESET_NAME = "provider";
+    static final String ITEM_PROVIDER_NAME = "itemProvider";
+
+    private final Map<String, ItemProviderContainer> itemProviders = new ConcurrentHashMap<>();
+    private final BundleContext bundleContext;
+
+    @Activate
+    public ProviderScriptExtension(BundleContext bundleContext) {
+        this.bundleContext = bundleContext;
+    }
+
+    @Override
+    public Collection<String> getDefaultPresets() {
+        return Set.of();
+    }
+
+    @Override
+    public Collection<String> getPresets() {
+        return Set.of(PRESET_NAME);
+    }
+
+    @Override
+    public Collection<String> getTypes() {
+        return Set.of(ITEM_PROVIDER_NAME);
+    }
+
+    @Override
+    public @Nullable Object get(String scriptIdentifier, String type) throws IllegalArgumentException {
+        if (ITEM_PROVIDER_NAME.equals(type)) {
+            return itemProviders.computeIfAbsent(scriptIdentifier, key -> {
+                ScriptedItemProvider itemProvider = new ScriptedItemProvider();
+                ServiceRegistration<ScriptedItemProvider> registration = bundleContext
+                        .registerService(ScriptedItemProvider.class, itemProvider, null);
+                return new ItemProviderContainer(itemProvider, registration);
+            }).itemProvider();
+        }
+
+        return null;
+    }
+
+    @Override
+    public Map<String, Object> importPreset(String scriptIdentifier, String preset) {
+        if (PRESET_NAME.equals(preset)) {
+            return Map.of(ITEM_PROVIDER_NAME, Objects.requireNonNull(get(scriptIdentifier, ITEM_PROVIDER_NAME)));
+        }
+
+        return Map.of();
+    }
+
+    @Override
+    public void unload(String scriptIdentifier) {
+        ItemProviderContainer itemProviderContainer = itemProviders.remove(scriptIdentifier);
+        if (itemProviderContainer != null) {
+            itemProviderContainer.registration().unregister();
+        }
+    }
+
+    private record ItemProviderContainer(ScriptedItemProvider itemProvider,
+            ServiceRegistration<ScriptedItemProvider> registration) {
+    }
+}

bundles/org.openhab.core.automation.module.script.rulesupport/src/main/java/org/openhab/core/automation/module/script/rulesupport/shared/ScriptedItemProvider.java

@@ -0,0 +1,73 @@
+/**
+ * Copyright (c) 2010-2024 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.module.script.rulesupport.shared;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.core.common.registry.AbstractProvider;
+import org.openhab.core.common.registry.ManagedProvider;
+import org.openhab.core.items.Item;
+import org.openhab.core.items.ItemProvider;
+
+/**
+ * This {@link ItemProvider} is used for a single ScriptEngine instance.
+ * It allows a script to provide items during its lifetime.
+ * This ensures that Items are not kept on reboot, but have to be provided by the script again.
+ *
+ * @author Florian Hotze - Initial contribution
+ */
+@NonNullByDefault
+public class ScriptedItemProvider extends AbstractProvider<Item>
+        implements ItemProvider, ManagedProvider<Item, String> {
+    private final Map<String, Item> items = new HashMap<>();
+
+    @Override
+    public Collection<Item> getAll() {
+        return items.values();
+    }
+
+    @Override
+    public @Nullable Item get(String itemName) {
+        return items.get(itemName);
+    }
+
+    @Override
+    public void add(Item item) {
+        items.put(item.getName(), item);
+
+        notifyListenersAboutAddedElement(item);
+    }
+
+    @Override
+    public @Nullable Item update(Item item) {
+        Item oldItem = items.get(item.getName());
+        if (oldItem != null) {
+            items.put(item.getName(), item);
+            notifyListenersAboutUpdatedElement(oldItem, item);
+        }
+        return oldItem;
+    }
+
+    @Override
+    public @Nullable Item remove(String itemName) {
+        Item item = items.remove(itemName);
+        if (item != null) {
+            notifyListenersAboutRemovedElement(item);
+        }
+        return item;
+    }
+}