import * as plugins from './smartchok.plugins'
import { Stringmap } from 'lik'

export type TSmartchokStatus = 'idle' | 'starting' | 'watching'
export type TFsEvent = 'add' | 'addDir' | 'change' | 'error' | 'unlink' | 'unlinkDir' | 'ready' | 'raw'

/**
 * Smartchok allows easy wathcing of files
 */
export class Smartchok {
  watchStringmap = new Stringmap()
  chokidarOptions: plugins.chokidar.WatchOptions
  status: TSmartchokStatus = 'idle'
  private watcher
  private watchingDeferred = plugins.q.defer<void>() // used to run things when watcher is initialized
  private eventObservablemap = new plugins.lik.Observablemap() // register one observable per event

  /**
   * constructor of class smartchok
   */
  constructor(watchArrayArg: string[], optionsArg: plugins.chokidar.WatchOptions = {}) {
    this.watchStringmap.addStringArray(watchArrayArg)
    this.chokidarOptions = optionsArg
  }

  /**
   * adds files to the list of watched files
   */
  add(pathArrayArg: string[]) {
    this.watchStringmap.addStringArray(pathArrayArg)
    if (this.status !== 'idle') {
      this.watchingDeferred.promise.then(() => {
        this.watcher.add(pathArrayArg)
      })
    }

  }

  /**
   * removes files from the list of watched files
   */
  remove(pathArg: string) {
    this.watchStringmap.removeString('') // TODO
    this.watchingDeferred.promise.then(() => {
      this.watcher.unwatch(pathArg)
    })
  }

  /**
   * gets an observable for a certain event
   */
  getObservableFor(fsEvent: TFsEvent): plugins.q.Promise<plugins.rx.Observable<any>> {
    let done = plugins.q.defer<plugins.rx.Observable<any>>()
    this.watchingDeferred.promise.then(() => {
      let eventObservable = this.eventObservablemap.getObservableForEmitterEvent(this.watcher, fsEvent)
      done.resolve(eventObservable)
    })
    return done.promise
  }

  /**
   * starts the watcher
   * @returns Promise<void>
   */
  start(): plugins.q.Promise<void> {
    let done = plugins.q.defer<void>()
    this.status = 'starting'
    this.watcher = plugins.chokidar.watch(this.watchStringmap.getStringArray(), this.chokidarOptions)
    this.watcher.on('ready', () => {
      this.status = 'watching'
      this.watchingDeferred.resolve()
      done.resolve()
    })
    return done.promise
  }

  /**
   * stop the watcher process if watching
   */
  stop() {
    let closeWatcher = () => {
      this.watcher.close()
    }
    if (this.status === 'watching') {
      console.log('closing while watching')
      closeWatcher()
    } else if (this.status === 'starting') {
      this.watchingDeferred.promise.then(() => { closeWatcher() })
    }
  }
}