var AWS = require('aws-sdk');
AWS.config.region = 'us-east-1'
var service = new AWS.CloudWatchLogs();

function getLogs(params) {
  params = Object.assign({}, params, { endTime: new Date().getTime() - 30000 })

  service.getLogEvents(p, function(err, data) {
    if (err) { console.log(err) }
    if (data && data.events && data.events.length !== 0) {
      data.events.forEach(function(event) {
        console.log(new Date(event.timestamp) + ' : ' + event.message)
      })
    }

    let nextParams = Object.assign({}, p, {
      startTime: undefined,
      nextToken: data.nextForwardToken
    })
    setTimeout(getLogs, 1000, nextParams)
  })
}

let logGroupName = process.argv[2]
let logStreamName = process.argv[3]

if (!logGroupName || !logStreamName) {
  return console.error('Usage: node cloudtail.js LogGroupName LogStreamName')
}

getLogs({
  logGroupName: logGroupName,
  logStreamName: logStreamName,
  startFromHead: false
})