// import RxClass from '@uci-utils/rx-class'
import path from 'path'
import { path as root } from 'app-root-path'
import json from 'jsonfile'
import to from 'await-to-js'

const internal = Symbol('token for Notifier Instance')
let inst

class Notifier {
  constructor(token,opts={}){
    if(token !== internal) {
      throw new Error('\'new Notifer\' not supported. Use the \'await Notifier.create()\' async static method')
    }
    // super(opts)
    this._services = {}
    this._disabled = []
    this.services = opts.services || {}
  }  // end constructor

  static async create(opts){
    inst = new Notifier(internal,opts)
    console.log('notifcation service registrations:',
      await Promise.all(
        Object.entries(inst.services).map(async service => {
          return await inst.registerService.call(inst,service[0],service[1])
        }
        )
      )
    )
    return inst
  }

  async registerService(name,opts) {
    let mod; let file
    let dir = `${root}/node_modules/${opts.module || name}`
    let [err,pkg] = await to(json.readFile(dir+'/package.json'))
    if (!err) {
      file = (dir + '/' + (pkg.main ? pkg.main : 'index.js'))
      // eslint-disable-next-line
      let [err,res] = await to(import(file))
      if (err) return `${name} failed - no file at ${file}`
      mod = res
    } else {
      // try in service directory for baked in plugins
      console.log(opts.module||name, ': no plugin found in node_modules, looking for internal module')
      let file = (`${path.dirname(__dirname)}/services/${name}.js`)
      // eslint-disable-next-line
      let [err,res] = await to(import(file))
      if (err) return `${name} failed - no file at ${file}`
      mod = res
    }

    // delete opts.module

    const Service = mod.Service || mod.default
    if (!Service.prototype.constructor) {
      console.log('no default or "Service" class was exported from plugin')
      return `${name} failed`
    }
    else this._services[name] = new Service(opts)
    return `${name} registered`
  }

  disableService(name) {
    this._disabled.push(name)
  }

  enableService(name) {
    this._disabled= this._disabled.filter(service=>service!==name)
  }

  async send (msg,service,opts={}) {
    if (service!==null || service==='!email') {
      if (this._services[service]) return await this._services[service].send(msg,opts)
    }
    let response = {}
    let services = Object.entries(this._services)
    if (service==='!email') services = services.filter(service => service[0]!=='email')
    // console.log('services for message send', services.map(service=>service[0]))
    await Promise.all(
      services.map(async service => {
        let res = this._disabled.includes(service[0]) ? 'disabled' : await service[1].send(msg,opts[service[0]])
        if (res.error) response.error ? response.error[service[0]] =  res.error : response = { error:{[service[0]]:res.error}}
        response[service[0]]=res
      }
      )
    )
    return response
  }

  getServicesList() { return Object.keys(this._services) }

  getService(name) {
    if (name==null) return this._services
    return this._services[name]
  }

} // end Notifier class


export default Notifier
export { Notifier }