/*
 * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.controller.cluster.datastore;

import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;
import com.typesafe.config.ConfigObject;

import java.util.ArrayList;
import java.util.List;

public class ConfigurationImpl implements Configuration {
    private final List<ModuleShard> moduleShards = new ArrayList<>();
    private final List<Module> modules = new ArrayList<>();


    public ConfigurationImpl(String moduleShardsConfigPath,
        String modulesConfigPath){
        Config moduleShardsConfig = ConfigFactory.load(moduleShardsConfigPath);
        Config modulesConfig = ConfigFactory.load(modulesConfigPath);

        readModuleShards(moduleShardsConfig);

        readModules(modulesConfig);
    }

    public List<String> getMemberShardNames(String memberName){

        List<String> shards = new ArrayList();
        for(ModuleShard ms : moduleShards){
            for(Shard s : ms.getShards()){
                for(String m : s.getReplicas()){
                    if(memberName.equals(m)){
                        shards.add(s.getName());
                    }
                }
            }
        }
        return shards;

    }


    private void readModules(Config modulesConfig) {
        List<? extends ConfigObject> modulesConfigObjectList =
            modulesConfig.getObjectList("modules");

        for(ConfigObject o : modulesConfigObjectList){
            ConfigObjectWrapper w = new ConfigObjectWrapper(o);
            modules.add(new Module(w.stringValue("name"), w.stringValue(
                "namespace"), w.stringValue("sharding-strategy")));
        }
    }

    private void readModuleShards(Config moduleShardsConfig) {
        List<? extends ConfigObject> moduleShardsConfigObjectList =
            moduleShardsConfig.getObjectList("module-shards");

        for(ConfigObject moduleShardConfigObject : moduleShardsConfigObjectList){

            String moduleName = moduleShardConfigObject.get("name").unwrapped().toString();

            List<? extends ConfigObject> shardsConfigObjectList =
                moduleShardConfigObject.toConfig().getObjectList("shards");

            List<Shard> shards = new ArrayList<>();

            for(ConfigObject shard : shardsConfigObjectList){
                String shardName = shard.get("name").unwrapped().toString();
                List<String> replicas = shard.toConfig().getStringList("replicas");
                shards.add(new Shard(shardName, replicas));
            }

            this.moduleShards.add(new ModuleShard(moduleName, shards));
        }
    }


    public static class ModuleShard {
        private final String moduleName;
        private final List<Shard> shards;

        public ModuleShard(String moduleName, List<Shard> shards) {
            this.moduleName = moduleName;
            this.shards = shards;
        }

        public String getModuleName() {
            return moduleName;
        }

        public List<Shard> getShards() {
            return shards;
        }
    }

    public static class Shard {
        private final String name;
        private final List<String> replicas;

        Shard(String name, List<String> replicas) {
            this.name = name;
            this.replicas = replicas;
        }

        public String getName() {
            return name;
        }

        public List<String> getReplicas() {
            return replicas;
        }
    }

    public static class Module {

        private final String name;
        private final String nameSpace;
        private final String shardingStrategy;

        Module(String name, String nameSpace, String shardingStrategy) {
            this.name = name;
            this.nameSpace = nameSpace;
            this.shardingStrategy = shardingStrategy;
        }

        public String getName() {
            return name;
        }

        public String getNameSpace() {
            return nameSpace;
        }

        public String getShardingStrategy() {
            return shardingStrategy;
        }
    }


    private static class ConfigObjectWrapper{

        private final ConfigObject configObject;

        ConfigObjectWrapper(ConfigObject configObject){
            this.configObject = configObject;
        }

        public String stringValue(String name){
            return configObject.get(name).unwrapped().toString();
        }
    }
}