import_month_to_date.js

'use strict'

/*******************************************************************************
Import month-to-date DBRs, overwriting the existing month-to-date.
*******************************************************************************/

var util = require('util')

var log = require('loglevel')
var rollbar = require('rollbar')
var moment = require('moment')

var BaseParser = require('./lib/baseparser.js')
var DBR = require('./lib/dbr.js')
var Redshift = require('./lib/redshift.js')
var cliUtils = require('./lib/cliutils.js')

rollbar.init(process.env.ROLLBAR_TOKEN, {environment: process.env.ROLLBAR_ENVIRONMENT})
rollbar.handleUncaughtExceptions(process.env.ROLLBAR_TOKEN,
                                 {exitOnUncaughtException: true})

var parser = new BaseParser({
  version: '0.0.1',
  addHelp: true,
  description: 'Imports month-to-date detailed billing reports'
})

parser.addArgument(
  ['--no-stage'], {
    action: 'storeConst',
    dest: 'no_stage',
    help: 'Use an existing staged month-to-date DBR.',
    constant: true
  }
)

var args = parser.parseArgs()

if (args.debug) {
  log.setLevel('debug')
  log.debug('Debugging output enabled.')
} else {
  log.setLevel('info')
}
log.debug(`Resolved invocation arguments were:\n${util.inspect(args)}`)

// Instantiate a DBR object to work with.
var dbrClientOptions = {
  accessKeyId: args.source_key,
  secretAccessKey: args.source_secret
}

var stagingClientOptions = {
  accessKeyId: args.staging_key,
  secretAccessKey: args.staging_secret
}

var dbr = new DBR(dbrClientOptions, stagingClientOptions,
                  args.source_bucket, args.staging_bucket)

// Instantiate a Redshift object to work with.
var redshift = new Redshift(args.redshift_uri, {
      key: args.staging_key,
      secret: args.staging_secret
})

let startTime = moment.utc()

dbr.getMonthToDateDBR()
  .then(stageDBRCheck)
  .then(importDBR)
  .then(vacuum)
  .then(function () {
    cliUtils.runCompleteHandler(startTime, 0)
  })
  .catch(cliUtils.rejectHandler)

// Determine whether to stage the latest month-to-date DBR or reuse existing
function stageDBRCheck (monthToDateDBR) {
  log.info(`Found month-to-date for ${monthToDateDBR.Month.format('MMMM YYYY')}...`)
  if (args.no_stage) {
    let s3uri = dbr.composeStagedURI(monthToDateDBR)
    log.info(`--no-stage specified, Attempting to use existing staged month-to-date DBR`)
    return s3uri
  } else {
    log.info(`Staging DBR file for ${monthToDateDBR.Month.format('MMMM YYYY')}.`)
    return dbr.stageDBR(monthToDateDBR.Month)
  }
}

// Import the staged month-to-date DBR
// TODO if we just chain like .then(redshift.importMonthToDate), it fails
// because 'this' inside importMonthToDate will be undefined. Why?
function importDBR (s3uri) {
  log.info(`Importing ${s3uri} into month_to_date...`)
  return redshift.importMonthToDate(s3uri)
}

// Run VACUUM on the month_to_date table
function vacuum () {
  if (!args.no_vacuum) {
    log.info('Running VACUUM on line_items...')
    return redshift.vacuum('month_to_date')
  } else {
    log.info('--no-vacuum specified, skiping vacuum.')
    return
  }
}