import * as smartq from 'smartq'
import { Subject } from 'rxjs'

import * as plugins from './smartcli.plugins'

// import classes
import { Objectmap } from 'lik'

// interfaces
export interface ICommandPromiseObject {
  commandName: string,
  promise: Promise<void>
}

export interface ITriggerObservableObject {
  triggerName: string
  subject: Subject<any>
}

export class Smartcli {
  argv: any
  questionsDone
  parseStarted: smartq.Deferred<any>
  commands
  questions
  version: string

  /**
   * map of all Command/Promise objects to keep track
   */
  allCommandPromisesMap = new Objectmap<ICommandPromiseObject>()

  /**
   * map of all Trigger/Observable objects to keep track
   */
  allTriggerObservablesMap = new Objectmap<ITriggerObservableObject>()

  constructor() {
    this.argv = plugins.yargs
    this.questionsDone = smartq.defer()
    this.parseStarted = smartq.defer()
  }

  /**
   * adds an alias, meaning one equals the other in terms of command execution.
   */
  addCommandAlias(keyArg, aliasArg): void {
    this.argv = this.argv.alias(keyArg, aliasArg)
    return
  }

  /**
   * adds a Command by returning a Promise that reacts to the specific commandString given.
   * Note: in e.g. "npm install something" the "install" is considered the command.
   */
  addCommand(commandNameArg: string): Promise<any> {
    let done = smartq.defer<any>()
    this.allCommandPromisesMap.add({
      commandName: commandNameArg,
      promise: done.promise
    })
    this.parseStarted.promise
      .then(() => {
        if (this.argv._.indexOf(commandNameArg) === 0) {
          done.resolve(this.argv)
        } else {
          done.reject(this.argv)
        }
      })
    return done.promise
  }

  /**
   * gets a Promise for a command word
   */
  getCommandPromiseByName(commandNameArg: string): Promise<void> {
    return this.allCommandPromisesMap.find(commandDeferredObjectArg => {
      return commandDeferredObjectArg.commandName === commandNameArg
    }).promise
  }

  /**
   * adds a Trigger. Like addCommand(), but returns an subscribable observable 
   */
  addTrigger(triggerNameArg: string) {
    let triggerSubject = new Subject<any>()
    this.allTriggerObservablesMap.add({
      triggerName: triggerNameArg,
      subject: triggerSubject
    })
    this.addCommand(triggerNameArg).then(() => {
      triggerSubject.next(this.argv)
    })
    return triggerSubject
  }

  /**
   * execute trigger by name
   * @param commandNameArg - the name of the command to trigger
   */
  trigger(triggerName: string) {
    let triggerSubject = this.allTriggerObservablesMap.find(triggerObservableObjectArg => {
      return triggerObservableObjectArg.triggerName === triggerName
    }).subject
    triggerSubject.next(this.argv)
    return triggerSubject
  }

  /**
   * allows to specify help text to be printed above the rest of the help text
   */
  addHelp(optionsArg: {
    helpText: string
  }) {
    this.addCommand('help').then(argvArg => {
      plugins.beautylog.log(optionsArg.helpText)
    })
  }

  /**
   * specify version to be printed for -v --version
   */
  addVersion(versionArg: string) {
    this.version = versionArg
    this.addCommandAlias('v', 'version')
    this.parseStarted.promise
      .then(() => {
        if (this.argv.v) {
          console.log(this.version)
        }
      })
  }

  /**
   * returns promise that is resolved when no commands are specified
   */
  standardTask(): Promise<any> {
    let done = smartq.defer<any>()
    this.allCommandPromisesMap.add({
      commandName: 'standard',
      promise: done.promise
    })
    this.parseStarted.promise
      .then(() => {
        if (this.argv._.length === 0 && !this.argv.v) {
          done.resolve(this.argv)
        } else {
          done.reject(this.argv)
        }
      })
    return done.promise
  }

  /**
   * start the process of evaluating commands
   */
  startParse(): void {
    this.argv = this.argv.argv
    this.parseStarted.resolve()
    return
  }

}