module.exports = client => {
    const constant = require('./constant'),
        schedule = require('node-schedule'),
        size = 500,
        deleteDup = async () => {
            const count = { deleted: 0, total: 0 }
            let lastsort = undefined, result = undefined, last = undefined
            do {
                result = await client.search({
                    index: constant.index,
                    size: size,
                    body: {
                        query: {
                            match_all: {}
                        },
                        sort: [{
                            "instance": {
                                "order": "asc"
                            },
                            "last": {
                                "order": "desc",
                                "numeric_type": "date_nanos",
                                "format": "strict_date_optional_time_nanos"
                            }
                        }],
                        search_after: lastsort
                    }
                })
                for (const instance of result.hits.hits) {
                    if (last && instance._source && last.instance === instance._source.instance) {
                        await client.delete({ index: index, id: instance._id })
                        count.deleted++
                        console.log('deleted ' + instance._id + ': ' + instance._source.instance)
                    }
                    else {
                        last = instance._source
                    }
                    if (instance._id === result.hits.hits[result.hits.hits.length - 1]._id) {
                        lastsort = instance.sort
                    }
                }
                count.total += result.hits.hits.length
                if (result.hits.hits.length !== size) {
                    break
                }
            } while (result.hits && result.hits.hits && result.hits.hits.length > 0)
            return console.log('Index: ' + constant.index + ' - Total: ' + count.total + ' - Deleted: ' + count.deleted)
        },
        job = schedule.scheduleJob('0 ' + constant.taskdeletedup + ' * * *', async () => {
            await deleteDup()
        })
}