import i2c from 'i2c-bus'
import pify from 'pify'
import btc from 'better-try-catch'
import Base from '@uci/base'

import logger from '@uci/logger'
let log = {}

export default class Bus extends Base {
  constructor(opts) {
    log = logger({name:'i2c-bus',id:opts.id,file:'src/bus.js',class:'Bus'})
    if (opts.path) opts.ns ={path:opts.path}
    if(!opts.ns) opts.ns = {path:'i2c-bus'}
    opts.sockets = (opts.sockets ? (opts.sockets+',') : '') + 'ns#s>n'
    if(opts.tcp) {
      if (typeof opts.tcp==='number') opts.ts ={port:opts.tcp}
      else opts.ts = {port:1776}
      opts.sockets = (opts.sockets ? (opts.sockets+',') : '') + 'ts#s>t'
    }
    super(opts)
    log.info({opts:opts},'created bus with these opts')
    console.log({opts:opts},'\n created bus with these opts')
    this.busnum = opts.busnum || 1
    this.i2cbus = i2c.open(this.busnum, () => {})
    this.bus = bus_funcs
    // this.init = this.init.bind(this)
  }

  async init(){
    await super.init()
  }

  // TODO see if default processing of base can handle this now
  async _packetProcess (sname,packet){
    // console.log('incoming packet', sname, packet)
    if (!packet.cmd) return  {error: 'no cmd: key in packet', packet: packet }
    if (this.bus[packet.cmd]) {
      let checked = validateArgs(packet)  // handle with before hook
      if (checked.error) return checked.error
      let [err,res] = await btc(this.bus[packet.cmd].bind(this))(packet.args)
      if (err) return {error: err.msg, packet:packet}
      packet.response = res
      packet.cmd = 'reply'
      return packet
    } else return  {error: 'no i2c bus function available for packet command', packet: packet }
  }

} // end of Bus Packet Class


const validateArgs = function (packet) {
  let missing = []
  const ne = arg => { if (packet.args[arg]===undefined) missing.push(arg) }
  // console.log('validate packet',packet)
  if (packet.cmd==='scan' || packet.cmd ==='close') return {}
  ne('address')
  switch (packet.cmd)
  {
  case 'readRaw':
  case 'writeRaw':
    ne('length')
    ne('buffer')
    break
  case 'read':
  case 'read2':
  case 'write':
  case 'write2':
    ne('cmd')
  }
  switch (packet.cmd)
  {
  case 'write':
  case 'write2':
  case 'send':
    ne('byte')
  }
  if (missing.length > 0) {
    return {error: `following bus arguments are missing ${missing}`, packet: packet }
  }
  return {}
}

const bus_funcs = {
  scan: function () { return pify(this.i2cbus.scan).bind(this.i2cbus)() },
  close: function () { return pify(this.i2cbus.close).bind(this.i2cbus)() },
  readRaw: function (args) {
    return pify(this.i2cbus.i2cRead).bind(this.i2cbus)(args.address, args.length, args.buffer)
  },
  writeRaw: function (args) {
    return pify(this.i2cbus.i2cWrite).bind(this.i2cbus)(args.address, args.length, args.buffer)
  },
  read: function (args) {
  // console.log('read: address, cmd', address, cmd)
    return pify(this.i2cbus.readByte).bind(this.i2cbus)(args.address, args.cmd)
  },
  write: function (args) {
    // console.log('write: address, cmd, byte', args.address, args.cmd, args.byte)
    return pify(this.i2cbus.writeByte.bind(this.i2cbus))(args.address, args.cmd, args.byte)
  },
  read2: function (args) {
    return pify(this.i2cbus.readWord.bind(this.i2cbus))(args.address, args.cmd)
  },
  write2: function (args) {
    return pify(this.i2cbus.writeWord.bind(this.i2cbus))(args.address, args.cmd, args.byte)
  },
  receive: function (args) {
  // console.log('receivebyte', address)
    return pify(this.i2cbus.receiveByte.bind(this.i2cbus))(args.address)
  },
  send: function (args) {
  // console.log('sendbyte', address,byte)
    return pify(this.i2cbus.sendByte.bind(this.i2cbus))(args.address, args.byte)
  }
} //end i2c functions