demo-store.js

const {flags} = require('@oclif/command')
const Command = require('../base')
const chalk = require('chalk')
const unzipper = require('unzipper')
const ora = require('ora')
const got = require('got')
const fs = require('fs')
const inquirer = require('inquirer')
const {sep} = require('path')
const spawner = require('../helpers/spawner')
const Auth = require('../helpers/auth')
const {makeConfig} = require('../helpers/config')
const envWriter = require('../helpers/env-writer')
const globalFlags = require('../helpers/global-flags')
const streamWriter = require('../helpers/stream-writer')

class DemoStoreCommand extends Command {
  requiresAuth() {
    const {flags: {'no-login': noLogin}} = this.parse(DemoStoreCommand)
    return !noLogin
  }

  async run() {
    this.cache = makeConfig('.checcache')
    let {args: {store}} = this.parse(DemoStoreCommand)

    // Check that the user provided a store and if it's something that's known before going and updating our cache
    if (!store || !this.getStoreFromCache(store)) {
      await this.retrieveStores()
    }

    // If the user didn't specify a store, ask them
    if (!store) {
      store = await this.askForStore()
    }

    // Get the "manifest" that defines the store
    const manifest = this.getStoreFromCache(store)

    // No manifest means that they probably gave a store name that doesn't exist
    if (!manifest) {
      this.log(`Could not find store matching "${store}". Try ${chalk.dim('chec demo-store')} for a list of options`)
      return
    }

    // Download the example and pool all the data together
    const data = {
      instructions: '',
      npm: false,
      buildScripts: [],
      ...manifest,
      ...await this.downloadExample(manifest),
    }

    // Display some sort of completion message and then run the example
    this.displayCompletion(data)
    try {
      await this.runExample(data)
    } catch (error) {
      this.error(error.message)
    }
  }

  /**
   * Retreive all the stores that can be shown by getting the master list from the example-stores repo
   *
   * @return {Promise<Array>} A promise that resolves to the list of stores fetched freshly from GitHub
   */
  async retrieveStores() {
    if (this.stores) {
      return this.stores
    }

    const spinner = ora({
      text: 'Loading example stores...',
      stream: process.stdout,
    }).start()

    const manifest = await got('https://raw.githubusercontent.com/chec/example-stores/master/manifest.json').then(
      response => JSON.parse(response.body)
    )

    spinner.stop()

    this.cache.set({storeManifest: manifest})
    this.stores = manifest

    return this.stores
  }

  /**
   * Ask the user to specify a store from those that are available
   *
   * @return {Promise<string>} A promise that resolves to the slug for the chosen store
   */
  async askForStore() {
    // Grab the stores and _clone_ the array
    const stores = (await this.retrieveStores()).slice(0)

    // Return the only store if there's one
    if (stores.length === 1) {
      return stores.pop().slug
    }

    // Prep a closure to shorten the demo store description
    const wrapString = string => {
      const singleLine = string.replace(/[\n\r]+/g, ' ')
      if (singleLine.length > 40) {
        return `${singleLine.substring(0, 37)}...`
      }
      return singleLine
    }

    const {slug} = await inquirer.prompt([{
      type: 'list',
      name: 'slug',
      message: 'Please choose a demo store to install:',
      choices: stores.map(store => ({
        name: `${chalk.bold(store.name)} ${chalk.dim(`(${store.slug})`)}: ${wrapString(store.description || '')}`,
        value: store.slug,
      })),
    }])

    return slug
  }

  /**
   * Get the destination directory where the example project should be downloaded to. This will cause the command to
   * exit if the calculated destination direction already exists and is not empty
   *
   * @param {object} manifest The "manifest" for the store that is being downloaded
   * @return {string} The directory that the example should be downloaded to
   */
  getDestinationDirectory(manifest) {
    // Run this only once
    if (this.destinationDirectory) {
      return this.destinationDirectory
    }

    // Allow specifying a target directory before defaulting to the stores slug
    const {args: {targetDirectory}} = this.parse(DemoStoreCommand)

    this.destinationDirectory = targetDirectory && targetDirectory.startsWith(sep) ?
      targetDirectory : `${process.cwd()}${sep}${targetDirectory || manifest.slug}`

    // Check if the folder exists
    try {
      fs.accessSync(this.destinationDirectory)
    } catch (error) {
      if (error.code === 'ENOENT') {
        // Folder doesn't exist which is fine
        return this.destinationDirectory
      }
      throw error
    }

    // Check that if the directory exists, it's empty
    if (fs.readdirSync(this.destinationDirectory).length > 0) {
      this.log(chalk.yellow(`The destination directory (${chalk.white.dim(
        this.destinationDirectory
      )}) already exists and is not empty`))
      this.exit(1)
    }

    return this.destinationDirectory
  }

  /**
   * Download the given store (defined by its manifest)
   *
   * @param {object} manifest The "manifest" for the store that is being downloaded
   * @return {Promise<object>} A promise that resolves into further config provided by the downloaded store
   */
  downloadExample(manifest) {
    // Pull just the repo name as the downloaded archive from GitHub uses this
    const [, repoName] = manifest.githubSlug.split('/', 2)
    const branch = manifest.branch || 'master'
    // We want to strip this useless directory out of our downloaded content
    const ignoreDirectory = `${repoName}-${branch}${sep}`
    // Prep the destination directory
    const destinationDirectory = this.getDestinationDirectory(manifest)

    // Form the URL for the zip bundle
    const url = `https://github.com/${manifest.githubSlug}/archive/${
      branch.replace(/[^a-z0-9._-]+/gi, '-')
    }.zip`
    this.log(`Downloading from ${chalk.dim(url)}`)

    // Start streaming the example
    const spinner = ora({
      text: 'Downloading example...',
      stream: process.stdout,
    }).start()

    // Assume the project won't define additional config
    let configResolver = Promise.resolve({})

    return new Promise((resolve, reject) => {
      const zipStream = got.stream(url).on('error', error => {
        reject(new Error(`Unexpected error occurred fetching ${chalk.dim(url)}. (${error.statusCode || error.message})`))
      })

      // Pipe the zip into an unzip parser
      return zipStream
      .pipe(unzipper.Parse()) // eslint-disable-line new-cap
      // Define custom logic when processing individual paths
      .on('entry', entry => {
        // Ignore (specficially) the useless directory or anything that's not within that directory
        if (entry.type === 'Directory' || entry.path.indexOf(ignoreDirectory) !== 0) {
          entry.autodrain()
          return
        }

        // Write the file to the destination directory minus the useless folder path
        const writer = streamWriter.create({path: `${destinationDirectory}${sep}${entry.path.substring(ignoreDirectory.length)}`})
        entry.pipe(writer)

        // If there's additional config within the root, resolve that and create a promise to resolve
        if (entry.path === `${ignoreDirectory}.chec.json`) {
          configResolver = new Promise(resolve => {
            const chunks = []

            entry.on('data', chunk => chunks.push(chunk))
            entry.on('end', () => resolve(JSON.parse(Buffer.concat(chunks).toString())))
          })
        }
      })
      .on('finish', resolve)
    })
    .then(() => {
      // Stop the spinner and resolve this promise with additional config instead
      spinner.succeed(chalk.green(`Downloaded ${chalk.white(manifest.slug)} to ${chalk.white(destinationDirectory)}`))
      return configResolver
    })
    .catch(error => {
      spinner.fail(error.message)
      this.exit(1)
    })
  }

  /**
   * Display a formatted message indicating the given store has been downloaded properly
   *
   * @param {object} manifest The "manifest" for the store that is being downloaded
   */
  displayCompletion(manifest) {
    this.log(`${chalk.bold(manifest.name)}

${chalk.dim(manifest.description)}`)
  }

  /**
   * Attempt to run the example store that was downloaded by installing dependencies with NPM or Yarn and running
   * any additional configued commands
   *
   * @param {object} manifest The "manifest" for the store that is being downloaded
   * @return {Promise} Resolves when NPM installation (if applicable) is complete and further commands have finished
   */
  async runExample(manifest) {
    const {npm, buildScripts} = manifest

    await this.writeEnv(manifest)

    // Don't continue if there's no NPM configuration
    if (!npm) {
      return
    }

    // Allow "yarn" to be used
    const command = npm === 'yarn' ? 'yarn' : 'npm'
    // Run the commands in the destination directory
    const cwd = this.getDestinationDirectory()
    // Prep the args that will be added to the run command
    const baseArgs = npm === 'yarn' ? ['--cwd', cwd] : ['--prefix', cwd]

    // Spawn a subprocess for dependency installation
    await spawner
    .create(command, [...baseArgs, 'install'], {env: {
      FORCE_COLOR: true,
      npm_config_color: 'always', // eslint-disable-line camelcase
      npm_config_progress: true, // eslint-disable-line camelcase
      ...process.env,
    }})
    .withSpinner('Installing NPM dependencies...')
    .streamOutput(true, true)
    .run()

    // Handle opting out of seeding
    let {flags: {'no-seed': noSeed}} = this.parse(DemoStoreCommand)
    if (noSeed) {
      this.log(chalk.yellow('Skipping seeding sample data.'))
      const seedIndex = buildScripts.indexOf('seed')
      if (seedIndex > -1) {
        buildScripts.splice(seedIndex, 1)
      }
    }

    this.log(chalk.dim('Running additional build/seed scripts...'))
    for (const script of buildScripts) {
      // eslint-disable-next-line no-await-in-loop
      await spawner.create(command, [...baseArgs, 'run', script], {stdio: 'inherit'}).run()
    }
  }

  /**
   * Attempts to write an env file to the destination directory of the installed store, using "dotenv" configuration
   * from the "manifest" and also `--env` flag configration
   *
   * @param {Object} manifest The store "manifest"
   */
  async writeEnv(manifest) {
    const {flags: {env}} = this.parse(DemoStoreCommand)

    const options = manifest.dotenv ? manifest.dotenv : {}

    // Check and parse the `--env` configuration
    if (Array.isArray(env)) {
      env.forEach(envDefinition => {
        const matches = envDefinition.match(/^([\w\d_]+)=(.+)$/i)
        if (!matches) {
          this.log(chalk.red(`Could not parse env definition: ${envDefinition}. Please provide env settings as key=value. Eg. --env key=value`))
          return
        }

        options[matches[1]] = matches[2]
      })
    }

    if (Object.entries(options).length === 0) {
      return
    }

    // Check for "dotenv" settings and update/write a .env file
    const writer = await envWriter.create(`${this.getDestinationDirectory(manifest)}${sep}.env`)
    let failed = false

    Object.entries(options).forEach(([key, value]) => {
      try {
        return writer.set(key, this.substituteEnvVars(value, key))
      } catch (error) {
        this.log(error.message)
        failed = true
      }
    })

    if (failed) {
      throw new Error('Could not write the required .env file')
    }

    return writer.writeFile()
  }

  /**
   * Takes a value (defined by "dotenv" configuration) and attempts to substitute known placeholders into their intended values
   *
   * @param {string} value The initial value set in the "dotenv" configuration
   * @param {string} key The key of this value in the "dotenv" configuration
   * @returns {string} The parsed value
   */
  substituteEnvVars(value, key) {
    const {flags: {domain}} = this.parse(DemoStoreCommand)

    const matchers = [
      {
        regex: /^%chec_([ps])key%$/,
        getter: matches => {
          if (!Auth.isLoggedIn()) {
            throw new Error(`${chalk.red('Could not set keys in an env file as you are not logged in!')} This store requires a .env file with your Chec public key provided as "${key}"`)
          }

          return Auth.getApiKey(true, matches[1] === 'p' ? 'public' : 'secret').key
        },
      },
      {
        regex: /^%chec_api_url%$/,
        getter: () => domain === 'chec.local' ? `http://api.${domain}` : `https://api.${domain}`,
      },
    ]

    return matchers.reduce((acc, {regex, getter}) => {
      if (typeof acc !== 'string') {
        return acc
      }

      const matches = acc.match(regex)

      if (!matches) {
        return acc
      }

      return getter(matches)
    }, value)
  }

  /**
   * Attempt to load a manifest from the cache for the given slug that refers to a store. A null result here might
   * indicate that the cached store list is just out of date
   *
   * @param {string} store The "slug" that refers to a store
   * @return {object|null} The cached manifest for the store or null if the cache doesn't have a manifest for the given slug
   */
  getStoreFromCache(store) {
    return (this.cache.get('storeManifest') || []).find(candidate => candidate.slug === store)
  }
}

DemoStoreCommand.args = [
  {
    name: 'store',
    description: 'The store that you want your example based off of',
  },
  {
    name: 'targetDirectory',
    description: 'The destination directory name to download the example to. The defaults to the store name',
    default: null,
  },
]

DemoStoreCommand.flags = {
  env: flags.string({
    description: 'Extra env variables to set for a .env file in the installed project',
    multiple: true,
  }),
  'no-login': flags.boolean({
    description: 'Optionally skip the login requirement. This is likely to be incompatible with example stores that are available for download',
    default: false,
  }),
  'no-seed': flags.boolean({
    description: 'Optionally skip seeding sample data into your Chec account',
    default: false,
  }),
  ...globalFlags,
}

DemoStoreCommand.description = `Create a demo store using Chec and Commerce.js
This command will download an example project from GitHub and initialise it on your machine. You will be free to edit the downloaded code and play around with Commerce.js in client code
`
module.exports = DemoStoreCommand