search.js

const fs = require( "fs" );
const client = require( "./esConfig" );
const data = JSON.parse( fs.readFileSync( "./city_list.json" ) );

const index = "weather";
const type = "cities";

async function writeToEs( index, data ){
    const bulkArray = [];
    for( let i = 0;i <= data.length;i++ ){
        bulkArray.push( {
            index:{
                _index:index, _type:type, _id:i
            }
        } );
        if( typeof data[i] !== "undefined" ){
            bulkArray.push( {id:data[i]["city"]["id"]["$numberLong"],
                            name:data[i]["city"]["name"],
                            findName:data[i]["city"]["findName"],
                            country:data[i]["city"]["country"]} );
        }
    }
    client.bulk( {body:bulkArray} )
    .then( response=>response )
    .catch( e=>{
        console.error( e );  //eslint-disable-line no-console
    } );

}

async function createMapping( index ){
    const cityScehema = {
        "name":"String",
        "findName":"String",
        "country":"String",
        "id":"long"
    }
    return client.indices.putMapping( {index:index, body:{properties:cityScehema}} );
}

module.exports = {

    async search( param, callback ){
        const resultArray = [];
        const {body} = await client.search( {
            index:index,
            body:{
                query:{
                    wildcard:{
                        name:`*${param.toLowerCase()}*`
                    }
                }
            }
        } ).catch( err=>console.error( err ) ); //eslint-disable-line no-console
        for( let j = 0;j < body.hits.hits.length;j++ ){
            resultArray.push( body.hits.hits[j]["_source"] );
        }
        callback( resultArray );
    },

    async cityListIndexing(){
        if( client.indices.exists( {index:index} ) ){
            client.indices.delete( {index: index} );
        }
        await client.indices.create( {index} );
        createMapping( client, index );
        writeToEs( index, data );
    }
}