// local imports
import Rsync from './rsync'
// native imports
import { EventEmitter as Emitter } from 'events'
import { dirname } from 'path'
// third party elements
import merge from 'aggregation/es6'
import { readFile } from 'fs-read-data'
import Conf from 'conf'
import debounce from 'debounce-fn'
import pathExists from 'path-exists'
import to from 'await-to-js'
// uci imports
import logger from '@uci-utils/logger'
import Watcher from '@uci-utils/watcher'
let log = {} // declare module wide log to be set during construction

class Sync extends merge(Rsync, Emitter) {
  constructor(opts = {}) {
    super()
    log = logger({ package:'@uci/sync'})
    this.opts = opts
    this._debounce = opts.debounce || null
    this.syncHandler = opts.syncHandler || (()=>{})
    // TODO if opts include source and destination then call loadJob with them
    this.config = new Conf({projectName:'sync'})
    this.jobsDir = process.env.SYNC_JOBS_DIR  || opts.jobsDir || this.config.get('jobsDir') || dirname(this.config.path)
    this.sshDir = opts.sshDir || this.config.get('sshDir') || `${this.jobsDir}/ssh`
    this.optionsDir = opts.optionsDir || this.config.get('optionsDir') || `${this.jobsDir}/options`
    log.debug({jobsDir:this.jobsDir, sshDir:this.sshDir, optionsDir:this.optionsDir, msg:'configuration file directories'})
    this._watcher = new Watcher()
  }
  // getters and setters
  get watching() {return this._watcher.watching } // watcher active?
  get watcher() { return this._watcher}  // in case one need set a listerner for other purposes

  get defaultJobsDir() { return this.config.get('jobsDir', this.jobsDir) }
  set defaultJobsDir(jobsDir) {
    if (jobsDir==null) this.config.delete('jobsDir')
    else this.config.set('jobsDir', jobsDir)
  }

  setConfig(name,val) { this.config.set(name,val)}
  getConfig(name) { return this.config.get(name)}

  async setJobsDir(dir='',save) {
    let res = await pathExists(dir)
    if(res){
      this.jobsDir=dir
      if(save) this.setDefaultJobsDir()
      return res
    }
    else {
      log.warn(`${dir} path does not exist  - Jobs Directory remains ${this.jobsDir}`)
      return res
    }
  }

  // job and options processing

  async runJob(options) {
    await this.loadJob(options)
    this.live()
    this.execute(options)
  }

  async loadJob (options) {
    if (typeof options ==='string') options = await this.readOptionsFile(options,'job')
    if (!options.error) {
      for (const option in options) {
        if(option === 'optionsFile') {
          let opts = await this.readOptionsFile(options.optionsFile,'options')
          if (!opts.error) {
            Object.keys(opts).forEach( async opt => {
              await this.processOption(opt,opts[opt])
            })
          }
        }
        else {
          await this.processOption(option,options[option])
        }
      } // end loop
      this.dry()  // dry run by default must .live() .unset('n')
    }
  }


  // async listJobFiles(dir) {
  //   return await getFiles(['**','*.yaml','*.yml'],{ onlyfiles:true, cwd:dir || this.jobsDir})
  // }

  async readOptionsFile(filePath,type='job') {
    let dir = {job:this.jobsDir,options:this.optionsDir,ssh:this.sshDir}
    let [err,res] = await to(readFile(`${dir[type]}/${filePath}`))
    if (err) {
      [err,res] = await to(readFile(filePath))
      if (err) {
        err = {filePath:filePath, error:err, type:type, dir:dir[type], msg:`unable to read ${filePath} options file`}
        log.warn(err)
        return err
      }
    }
    return res
  }

  // executes a method on the instance (might be in prototype chain) which may take a value(s)
  async processOption (method, value)  {
    log.debug({method:method, value:value, msg:`processing option ${method} with value ${value}`})
    if (typeof(this[method]) === 'function') {
      await this[method](value)
    }
  }

  // methods ====================

  live() {
    this.unset('n')
  }

  set (option=[],value) {
    if (typeof option === 'string') super.set(option,value)  // pass through
    else {
      option.forEach( opt => {
        typeof opt==='string' ? super.set(opt) : super.set(...Object.entries(opt).flat())
      })
    }
    return this
  }

  async watch(cmd) {
    // TODO make into switch ?
    log.debug(`watch command ${cmd}`)

    if (isPlainObject(cmd) || cmd==null || (typeof cmd==='boolean' && cmd) || cmd==='init'  || cmd==='add') {
      if (cmd.wait) this.debounce(cmd)
      let opts = {source:this._sources, excludeFrom:this._excludeFiles, ignored:this._exclude }
      await this._watcher.init(opts)
      this.syncHandler = syncHandler.call(this,log)

      return
    }

    if (cmd==='remove') {
      this._watcher.removeListener('changed', this.syncHandler )
      this._watcher.remove()
      return
    }

    if (cmd ==='on'|| cmd==='start') {
      this._watcher.on('changed', this.syncHandler)
      this._watcher.start()
      return
    }

    if (cmd==='off' || cmd==='stop' ) {
      this._watcher.removeListener('changed', this.syncHandler)
      this._watcher.stop()
      return
    }

    if (cmd==='pause' ) {
      this._watcher.removeListener('changed', this.syncHandler)
      return
    }

    if (cmd==='resume') {
      this._watcher.on('changed', this.syncHandler)
      return
    }

    // 'changed' event handler with optional debounce wrapper
    function syncHandler(log) {
      function sync (change) {
        log.info({file:change.file, type:change.type, msg:`file ${change.file} was ${change.type}`})
        this.execute()
      }
      log.debug(`in sync make Handler, ${this._debounce}, ${sync}`)
      if (this._debounce==null) return sync.bind(this)
      return debounce(sync.bind(this),{wait:this.opts.debounce})
    }
  }

  debounce(opts) {
    if (opts==null) this._debounce=null
    this._debounce = opts
  }

  sshu (file) {
    if (file && (typeof options==='string')) {
      this.shell(`sshu -c ${file}`)
    }
  }

  async ssh (options) {
    if (!this.destination()) {
      log.warn({ssh:options, msg:'aborting ssh options - destination must be set before processing ssh option'})
      return this
    }
    if (typeof options==='string') {  // options is a filepath for ssh options
      let options = await this.readOptionsFile(options,'ssh')
      if (options.error) return this
    }

    if (options.host)
    {
      let username = options.username ? options.username+'@' : ''
      this.destination(`${username}${options.host}:${this.destination()}`)
    }
    else {
      log.warn({ssh:options, msg:'aborting ssh options, missing host value is required '})
      return this
    }
    let cmd = []
    // TODO allow all openssh client options
    if (options.privateKeyPath)  cmd.push(`-i ${options.privateKeyPath}`)
    if (options.port)  cmd.push(`-p ${options.port}`)
    if (options.configFile)  cmd.push(`-F ${options.privateKeyPath}`)
    if (cmd) this.shell(cmd.join(' '))

    return this
  }

  async execute(opts={}) {
    // log.info({cmd:this.command(), msg:'running rsync command'})
    const superexecute = super.execute.bind(this)
    return new Promise((resolve, reject) => {
      let status
      let errors
      this.rsyncpid = superexecute(
        function(err, code, cmd) {
          if (err) {
            log.fatal({error:err, code:code, cmd:cmd, msg:'error during sync'})
            reject ({error:err, code:code, cmd:cmd, msg:'error during sync'})
          }
          if (errors) log.warn({errors: errors, cmd:cmd, msg:'sync ran but with with errors'})
          log.debug({cmd:cmd, status:status, msg:'sync run'})
          resolve({cmd:cmd, errors:errors, status:status, msg:'sync run'})
        }, function(data) {
          status += data.toString()
          if (opts.cli) process.stdout.write(data.toString())
        },
        function(data) {
          errors += data.toString()
          if (opts.cli) process.stderr.write(data.toString())
        }
      )
    })
  }

}// end Class Sync

export default Sync


function isPlainObject (obj) {
  return Object.prototype.toString.call(obj) === '[object Object]'
}
//
// function escapeSpaces (str) {
//   if (typeof str === 'string') {
//     return str.replace(/\b\s/g, '\\ ')
//   } else {
//     return path
//   }
// }