/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.plugins.scanners;

import org.elasticsearch.plugins.PluginBundle;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * A registry of classes declared by plugins as named components.
 * Named components are classes annotated with @NamedComponent(name) and can be referred later by a name given in this annotation.
 * Named components implement/extend Extensibles (classes/interfaces marked with @Extensible)
 */
public class StablePluginsRegistry {

    /*
    A map of an interface/class name marked (effectively) with @Extensible to NameToPluginInfo map
    effectively means that an interface which extends another interface marked with @Extensible is also extensible
    NameToPluginInfo map is a map of Name to PluginInfo
    i.e.
    org.elasticsearch.plugin.analysis.TokenFilterFactory ->
        {"nori" -> {nori, org.elasticserach.plugin.analysis.new_nori.NoriReadingFormFilterFactory, classloaderInstance}
     */
    private final Map<String /*Extensible */, NameToPluginInfo> namedComponents;
    private final NamedComponentReader namedComponentReader;

    public StablePluginsRegistry() {
        this(new NamedComponentReader(), new HashMap<>());
    }

    // for testing
    public StablePluginsRegistry(NamedComponentReader namedComponentReader, Map<String /*Extensible */, NameToPluginInfo> namedComponents) {
        this.namedComponentReader = namedComponentReader;
        this.namedComponents = namedComponents;
    }

    public void scanBundleForStablePlugins(PluginBundle bundle, ClassLoader pluginClassLoader) {
        Map<String, NameToPluginInfo> namedComponentsFromPlugin = namedComponentReader.findNamedComponents(bundle, pluginClassLoader);
        for (Map.Entry<String, NameToPluginInfo> entry : namedComponentsFromPlugin.entrySet()) {
            namedComponents.compute(entry.getKey(), (k, v) -> v != null ? v.put(entry.getValue()) : entry.getValue());
        }
    }

    public Collection<PluginInfo> getPluginInfosForExtensible(String extensibleClassName) {
        NameToPluginInfo nameToPluginInfo = namedComponents.get(extensibleClassName);
        if (nameToPluginInfo != null) {
            return nameToPluginInfo.nameToPluginInfoMap().values();
        }
        return Collections.emptyList();
    }

}