/**
 * Copyright © 2016-2018 The Thingsboard Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.thingsboard.rule.engine.filter;

import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import lombok.extern.slf4j.Slf4j;
import org.thingsboard.rule.engine.api.RuleNode;
import org.thingsboard.rule.engine.api.TbContext;
import org.thingsboard.rule.engine.api.TbNode;
import org.thingsboard.rule.engine.api.TbNodeConfiguration;
import org.thingsboard.rule.engine.api.TbNodeException;
import org.thingsboard.rule.engine.api.util.TbNodeUtils;
import org.thingsboard.server.common.data.id.EntityId;
import org.thingsboard.server.common.data.id.EntityIdFactory;
import org.thingsboard.server.common.data.plugin.ComponentType;
import org.thingsboard.server.common.data.relation.EntityRelation;
import org.thingsboard.server.common.data.relation.EntitySearchDirection;
import org.thingsboard.server.common.data.relation.RelationTypeGroup;
import org.thingsboard.server.common.msg.TbMsg;

import java.util.List;

import static org.thingsboard.rule.engine.api.util.DonAsynchron.withCallback;

/**
 * Created by ashvayka on 19.01.18.
 */
@Slf4j
@RuleNode(
        type = ComponentType.FILTER,
        name = "check relation",
        configClazz = TbCheckRelationNodeConfiguration.class,
        relationTypes = {"True", "False"},
        nodeDescription = "Checks the relation from the selected entity to the originator of the message by type and direction" +
                " if 'Check for single entity' is set to true, otherwise rule node will check if exist" +
                " any relation to the originator of the message by type and direction.",
        nodeDetails = "If at least one relation exists - send Message via <b>True</b> chain, otherwise <b>False</b> chain is used.",
        uiResources = {"static/rulenode/rulenode-core-config.js"},
        configDirective = "tbFilterNodeCheckRelationConfig")
public class TbCheckRelationNode implements TbNode {

    private TbCheckRelationNodeConfiguration config;

    @Override
    public void init(TbContext ctx, TbNodeConfiguration configuration) throws TbNodeException {
        this.config = TbNodeUtils.convert(configuration, TbCheckRelationNodeConfiguration.class);
    }

    @Override
    public void onMsg(TbContext ctx, TbMsg msg) throws TbNodeException {
        ListenableFuture<Boolean> checkRelationFuture;
        if (config.isCheckForSingleEntity()) {
            checkRelationFuture = processSingle(ctx, msg);
        } else {
            checkRelationFuture = processList(ctx, msg);
        }
        withCallback(checkRelationFuture, filterResult -> ctx.tellNext(msg, filterResult ? "True" : "False"), t -> ctx.tellFailure(msg, t), ctx.getDbCallbackExecutor());
    }

    private ListenableFuture<Boolean> processSingle(TbContext ctx, TbMsg msg) {
        EntityId from;
        EntityId to;
        if (EntitySearchDirection.FROM.name().equals(config.getDirection())) {
            from = EntityIdFactory.getByTypeAndId(config.getEntityType(), config.getEntityId());
            to = msg.getOriginator();
        } else {
            to = EntityIdFactory.getByTypeAndId(config.getEntityType(), config.getEntityId());
            from = msg.getOriginator();
        }
        return ctx.getRelationService().checkRelation(ctx.getTenantId(), from, to, config.getRelationType(), RelationTypeGroup.COMMON);
    }

    private ListenableFuture<Boolean> processList(TbContext ctx, TbMsg msg) {
        if (EntitySearchDirection.FROM.name().equals(config.getDirection())) {
            return Futures.transformAsync(ctx.getRelationService()
                    .findByToAndTypeAsync(ctx.getTenantId(), msg.getOriginator(), config.getRelationType(), RelationTypeGroup.COMMON), this::isEmptyList);
        } else {
            return Futures.transformAsync(ctx.getRelationService()
                    .findByFromAndTypeAsync(ctx.getTenantId(), msg.getOriginator(), config.getRelationType(), RelationTypeGroup.COMMON), this::isEmptyList);
        }
    }

    private ListenableFuture<Boolean> isEmptyList(List<EntityRelation> entityRelations) {
        if (entityRelations.isEmpty()) {
            return Futures.immediateFuture(false);
        } else {
            return Futures.immediateFuture(true);
        }
    }

    @Override
    public void destroy() {

    }
}
