/**
 * 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.server.dao.audit.sink;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.entity.ContentType;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.nio.entity.NStringEntity;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.ResponseListener;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.http.HttpMethod;
import org.springframework.stereotype.Component;
import org.thingsboard.server.common.data.audit.AuditLog;
import org.thingsboard.server.common.data.id.TenantId;

import javax.annotation.PostConstruct;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Collections;

@Component
@ConditionalOnProperty(prefix = "audit_log.sink", value = "type", havingValue = "elasticsearch")
@Slf4j
public class ElasticsearchAuditLogSink implements AuditLogSink {

    private static final String TENANT_PLACEHOLDER = "@{TENANT}";
    private static final String DATE_PLACEHOLDER = "@{DATE}";
    private static final String INDEX_TYPE = "audit_log";

    private final ObjectMapper mapper = new ObjectMapper();

    @Value("${audit_log.sink.index_pattern}")
    private String indexPattern;
    @Value("${audit_log.sink.scheme_name}")
    private String schemeName;
    @Value("${audit_log.sink.host}")
    private String host;
    @Value("${audit_log.sink.port}")
    private int port;
    @Value("${audit_log.sink.user_name}")
    private String userName;
    @Value("${audit_log.sink.password}")
    private String password;
    @Value("${audit_log.sink.date_format}")
    private String dateFormat;

    private RestClient restClient;

    @PostConstruct
    public void init() {
        try {
            log.trace("Adding elastic rest endpoint... host [{}], port [{}], scheme name [{}]",
                    host, port, schemeName);
            RestClientBuilder builder = RestClient.builder(
                    new HttpHost(host, port, schemeName));

            if (StringUtils.isNotEmpty(userName) &&
                    StringUtils.isNotEmpty(password)) {
                log.trace("...using username [{}] and password ***", userName);
                final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
                credentialsProvider.setCredentials(AuthScope.ANY,
                        new UsernamePasswordCredentials(userName, password));
                builder.setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
            }

            this.restClient = builder.build();
        } catch (Exception e) {
            log.error("Sink init failed!", e);
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    @Override
    public void logAction(AuditLog auditLogEntry) {
        String jsonContent = createElasticJsonRecord(auditLogEntry);

        HttpEntity entity = new NStringEntity(
                jsonContent,
                ContentType.APPLICATION_JSON);

        restClient.performRequestAsync(
                HttpMethod.POST.name(),
                String.format("/%s/%s", getIndexName(auditLogEntry.getTenantId()), INDEX_TYPE),
                Collections.emptyMap(),
                entity,
                responseListener);
    }

    private String createElasticJsonRecord(AuditLog auditLog) {
        ObjectNode auditLogNode = mapper.createObjectNode();
        auditLogNode.put("postDate", LocalDateTime.now().toString());
        auditLogNode.put("id", auditLog.getId().getId().toString());
        auditLogNode.put("entityName", auditLog.getEntityName());
        auditLogNode.put("tenantId", auditLog.getTenantId().getId().toString());
        if (auditLog.getCustomerId() != null) {
            auditLogNode.put("customerId", auditLog.getCustomerId().getId().toString());
        }
        auditLogNode.put("entityId", auditLog.getEntityId().getId().toString());
        auditLogNode.put("entityType", auditLog.getEntityId().getEntityType().name());
        auditLogNode.put("userId", auditLog.getUserId().getId().toString());
        auditLogNode.put("userName", auditLog.getUserName());
        auditLogNode.put("actionType", auditLog.getActionType().name());
        if (auditLog.getActionData() != null) {
            auditLogNode.put("actionData", auditLog.getActionData().toString());
        }
        auditLogNode.put("actionStatus", auditLog.getActionStatus().name());
        auditLogNode.put("actionFailureDetails", auditLog.getActionFailureDetails());
        return auditLogNode.toString();
    }

    private ResponseListener responseListener = new ResponseListener() {
        @Override
        public void onSuccess(Response response) {
            log.trace("Elasticsearch sink log action method succeeded. Response result [{}]!", response);
        }

        @Override
        public void onFailure(Exception exception) {
            log.warn("Elasticsearch sink log action method failed!", exception);
        }
    };

    private String getIndexName(TenantId tenantId) {
        String indexName = indexPattern;
        if (indexName.contains(TENANT_PLACEHOLDER) && tenantId != null) {
            indexName = indexName.replace(TENANT_PLACEHOLDER, tenantId.getId().toString());
        }
        if (indexName.contains(DATE_PLACEHOLDER)) {
            LocalDateTime now = LocalDateTime.now();
            DateTimeFormatter formatter = DateTimeFormatter.ofPattern(dateFormat);
            indexName = indexName.replace(DATE_PLACEHOLDER, now.format(formatter));
        }
        return indexName.toLowerCase();
    }
}
