mkungla/atom-aframe

'use babel'

import { File, CompositeDisposable } from 'atom'
import semver from 'semver'

class PJW {
  /**
   * Use pathwatcher to check single file.
   * Since pathwatcher can not handle rename well use onDidChangeFiles
   */
  constructor () {
    this.clear()
    this.pkgj = new File(atom.project.resolvePath('./package.json'))
  }

  /**
   * clear values
   */
  clear () {
    this.semver = null
    this.version = null
    this.dependencies = false
    this.devDependencies = false
  }

  /**
   * @return {Boolean} indicating does project have A-Frame dependency
   */
  hasDependency () {
    return this.dependencies || this.devDependencies
  }

  /**
   * check package.json and try to read dependencies || devDependencies
   *
   * @return {Promise} resolves only on dependencies || devDependencies : reject
   */
  check () {
    this.clear()
    return new Promise((resolve, reject) => {
      let c
      if (this.pkgj.existsSync()) {
        this.pkgj.read(false).then(f => {
          try {
            c = JSON.parse(f)
            if (
              c.dependencies &&
              Object.prototype.hasOwnProperty.call(c.dependencies, 'aframe')
            ) {
              this.semver = c.dependencies.aframe
              this.dependencies = true
            } else if (
              c.devDependencies &&
              Object.prototype.hasOwnProperty.call(c.devDependencies, 'aframe')
            ) {
              this.semver = c.devDependencies.aframe
              this.devDependencies = true
            }
            if (this.semver) {
              this.version = semver.valid(this.semver) ? this.semver : null
              resolve()
            } else {
              reject(
                Error(
                  'Project package.json does not have aframe as dependencies or devDependencies'
                )
              )
            }
          } catch (e) {
            reject(e)
          }
        })
      } else {
        reject(Error('Project has no package.json file'))
      }
    })
  }

  /**
   * listen package.json
   */
  listen (cp) {
    if (!this.subscriptions) {
      this.subscriptions = new CompositeDisposable()
    } else {
      this.subscriptions.dispose()
      this.subscriptions = null
    }
    // TODO: file.onDidRename
    // https://github.com/atom/atom/pull/16124
    if (this.pkgj.existsSync()) {
      // listen changes
      this.subscriptions.add(
        this.pkgj.onDidChange(() => {
          this.listenCallback(cp)
        })
      )

      // listen delete
      this.subscriptions.add(
        this.pkgj.onDidDelete(() => {
          // reload observers
          this.stop()
          this.listen(cp)
        })
      )
      // listen rename away
      this.subscriptions.add(
        atom.project.onDidChangeFiles(ev => {
          for (const e of ev) {
            if (e.action === 'renamed' && e.oldPath === this.pkgj.path) {
              this.stop()
              this.listen(cp)
              break
            }
          }
        })
      )
    } else {
      // listen create rename to
      this.subscriptions.add(
        atom.project.onDidChangeFiles(ev => {
          for (const e of ev) {
            if (
              (e.action === 'renamed' || e.action === 'created') &&
              e.path === this.pkgj.path
            ) {
              this.stop()
              this.listen(cp)
            }
          }
        })
      )
    }
    // initial
    this.listenCallback(cp)
  }

  /**
   * listenCallback should replaced and called just with this.semver
   */
  listenCallback (cp) {
    this.check()
      .then(() => {
        if (this.hasDependency()) {
          cp(this.version, this.semver)
        }
      })
      .catch(e => {
        cp(null, this.semver)
      })
  }

  /**
   * stop current observers/listeners
   */
  stop () {
    if (this.subscriptions) {
      this.subscriptions.dispose()
      this.subscriptions = null
    }
    this.clear()
  }

  /**
   * dispose description
   *
   * @return {[type]} [description]
   */
  dispose () {
    this.stop()
  }
}
export { PJW }