'use strict'

let cli = require('heroku-cli-util')
let co = require('co')
let releases = require('../../releases')
let output = require('../../output')

function * run (context, heroku) {
  let release
  if (context.args.release) {
    let id = context.args.release.toLowerCase()
    id = id.startsWith('v') ? id.slice(1) : id
    release = yield heroku.get(`/apps/${context.app}/releases/${id}`)
  } else {
    release = yield releases.FindRelease(heroku, context.app, (releases) => releases.filter((r) => r.status === 'succeeded')[1])
  }

  let latest
  yield cli.action(`Rolling back ${cli.color.app(context.app)} to ${cli.color.green('v' + release.version)}`, { success: false }, co(function * () {
    latest = yield heroku.post(`/apps/${context.app}/releases`, { body: { release: release.id } })

    cli.action.done(`done, ${cli.color.green('v' + latest.version)}`)
    cli.warn(`Rollback affects code and config vars; it doesn't add or remove addons.
To undo, run: ${cli.color.cmd('heroku rollback v' + (latest.version - 1))}`)
  }))

  if (latest.output_stream_url) {
    cli.log('Running release command...')
    yield output.Stream(latest.output_stream_url)
      .catch(err => {
        if (err.statusCode === 404) {
          cli.warn('Release command starting. Use `heroku releases:output` to view the log.')
          return
        }
        throw err
      })
  }
}

let cmd = {
  description: 'rollback to a previous release',
  help: 'If RELEASE is not specified, it will rollback one release',
  needsApp: true,
  needsAuth: true,
  args: [{ name: 'release', optional: true }],
  run: cli.command({ preauth: true }, co.wrap(run))
}

module.exports = [
  Object.assign({ topic: 'releases', command: 'rollback' }, cmd),
  Object.assign({ hidden: true, topic: 'rollback' }, cmd)
]