'use strict'

const ora = require('ora')('Initializing...').start()
const Promise = require('bluebird')
const exec = require('child_process').exec
const fs = Promise.promisifyAll(require('fs-extra'))
const https = require('follow-redirects').https
const path = require('path')
const pm2 = Promise.promisifyAll(require('pm2'))
const tar = require('tar')
const zlib = require('zlib')
const _ = require('lodash')

let installDir = path.resolve(__dirname, '../..')

/**
 * Fetch version from npm package
 */
fs.readJsonAsync('package.json').then((packageObj) => {
  let remoteURL = _.replace('https://github.com/Requarks/wiki/releases/download/v{0}/wiki-js.tar.gz', '{0}', packageObj.version)

  return new Promise((resolve, reject) => {
    /**
     * Fetch tarball
     */
    ora.text = 'Looking for latest release...'
    https.get(remoteURL, resp => {
      if (resp.statusCode !== 200) {
        return reject(new Error('Remote file not found'))
      }
      ora.text = 'Install tarball found. Downloading...'

      /**
       * Extract tarball
       */
      resp.pipe(zlib.createGunzip())
      .pipe(tar.Extract({ path: installDir }))
      .on('error', err => reject(err))
      .on('end', () => {
        ora.text = 'Tarball extracted successfully.'
        resolve(true)
      })
    })
  })
}).then(() => {
  return new Promise((resolve, reject) => {
    ora.text = 'Installing Wiki.js npm dependencies...'
    let npmInstallProc = exec('npm install --only=production', {
      cwd: installDir
    })
    npmInstallProc.stdout.pipe(process.stdout)
    npmInstallProc.on('error', err => {
      reject(err)
    })
    .on('exit', () => {
      ora.text = 'Wiki.js npm dependencies installed successfully.'
      resolve(true)
    })
  })
}).then(() => {
  fs.accessAsync(path.join(installDir, 'config.yml')).then(() => {
    /**
     * Upgrade mode
     */
    ora.text = 'Upgrade succeeded. Reloading Wiki.js...'
    return pm2.connectAsync().then(() => {
      return pm2.restartAsync('wiki').catch(err => { // eslint-disable-line handle-callback-err
        return new Error('Unable to restart Wiki.js via pm2... Do a manual restart!')
      }).then(() => {
        ora.succeed('Wiki.js has restarted. Upgrade completed.')
      })
    }).catch(err => {
      ora.fail(err)
    }).finally(() => {
      pm2.disconnect()
    })
  }).catch(err => {
    /**
     * Install mode
     */
    if (err.code === 'ENOENT') {
      ora.text = 'First-time install, creating a new config.yml...'
      return fs.copyAsync(path.join(installDir, 'config.sample.yml'), path.join(installDir, 'config.yml')).then(() => {
        ora.succeed('Installation succeeded. You can now continue with the configuration steps. Check out https://docs.wiki.requarks.io/install for more info.')
      })
    } else {
      return err
    }
  })
}).catch(err => {
  ora.fail(err)
})