uid: jag_rules:scene_modification
label: Scene Modification
description: Respond to Scene Control Widget events and modify scene information accordingly
configDescriptions:
  - name: sceneModifier
    type: TEXT
    context: item
    label: Scene Widget Item
    required: true
    description: Name of the proxy item used by the scene contol widget
triggers:
  - id: "1"
    configuration:
      itemName: "{{sceneModifier}}"
    type: core.ItemStateChangeTrigger
conditions:
  - inputs: {}
    id: "3"
    configuration:
      itemName: "{{sceneModifier}}"
      state: None
      operator: "!="
    type: core.ItemStateCondition
actions:
  - inputs: {}
    id: "2"
    configuration:
      type: application/javascript
      script: >-
        /*

        This rule enacts changes to scene settings for the scene control system.

        */

        //Nashorn and JSscripting compatibility
        
        if(typeof(require) === "function") Object.assign(this, require('@runtime'));
        

        //Set Logger

        var logger = Java.type('org.slf4j.LoggerFactory').getLogger('org.openhab.rule.ModifyScene');


        //Access MetadataRegistry

        var FrameworkUtil = Java.type("org.osgi.framework.FrameworkUtil");

        this.ScriptHandler = Java.type("org.openhab.core.automation.module.script.rulesupport.shared.ScriptedHandler");

        var _bundle = FrameworkUtil.getBundle(ScriptHandler.class);
        
        var bundle_context = _bundle.getBundleContext()

        var classname = "org.openhab.core.items.MetadataRegistry"

        var MetadataRegistry_Ref = bundle_context.getServiceReference(classname);

        var MetadataRegistry = bundle_context.getService(MetadataRegistry_Ref);

        var Metadata = Java.type("org.openhab.core.items.Metadata");

        var MetadataKey = Java.type("org.openhab.core.items.MetadataKey");


        //Combine metadata configurations function

        _merge_configuration = function(metadata_configuration, new_configuration) {
        	var merged_configuration = {};
        	for (var property in metadata_configuration) {
        		merged_configuration[property] = metadata_configuration[property];
        	}

        	for (var property in new_configuration) {
        		merged_configuration[property] = new_configuration[property];
        	}
        	return merged_configuration;
        }


        //Collect all info from scene modify item state and existing metadata

        var modifyInfo = items[event.itemName].toString().split(',')

        var controllerName = modifyInfo[0];

        var targetName = modifyInfo[1];

        var modification = modifyInfo[2];

        var metadata = MetadataRegistry.get(new MetadataKey("ActiveItems",controllerName));


        //Take metadata write/delete action based on modification

        if (modification == 'ADD' || modification == 'REFRESH') {
          //Format metadata to write
          var targetState = items[targetName].toString();
          var targetData={};
          targetData[targetName]=targetState;

          //Write metadata
          if (metadata === null) {
            MetadataRegistry.add(new Metadata(new MetadataKey('ActiveItems', controllerName), null, targetData));
          } else {
            value = metadata.value;
            var new_configuration = _merge_configuration(metadata.configuration, targetData);
            MetadataRegistry.update(new Metadata(new MetadataKey('ActiveItems', controllerName), value, new_configuration));
          }

        } else { 
          //Remove metadata
          var new_configuration = _merge_configuration(metadata.configuration, {});
          delete new_configuration[targetName];
          MetadataRegistry.remove(new MetadataKey('ActiveItems', controllerName));
          MetadataRegistry.add(new Metadata(new MetadataKey('ActiveItems', controllerName), metadata.value, new_configuration));
        }


        //Cleanup

        logger.info([modification,targetName,'in',controllerName].join(' '));

        events.postUpdate(event.itemName,'None');
    type: script.ScriptAction