#!/usr/bin/env node

var path = require('path')
var cfgDir = path.join(process.env.XDG_CONFIG_HOME || (path.join(process.env.HOME || process.env.USERPROFILE, '/.config/')), 'telecommander/')
process.env.LOGGER_FILE = cfgDir+'log'

var os = require('os')
var fs = require('fs')
var moment = require('moment')
var blessed = require('blessed')

/* IF YOU FORK THE APP PLEASE CHANGE THE ID
 * AND HASH IN THE APP OBJECT! THEY IDENTIFY
 * THE APPLICATION CREATOR AND YOU CAN
 * OBTAIN YOURS FROM http://my.telegram.org
 */
var app = {
  id: '42419',
  hash: '90a3c2cdbf9b391d9ed72c0639dc0786',
  version: require('./package.json').version,
  lang: 'en',
  deviceModel: os.type(),
  systemVersion: os.platform()+'/'+os.release()
}

try { fs.makeDirSync(cfgDir,'0770') } catch (e) { }

var getLogger = require('get-log')
getLogger.PROJECT_NAME = 'telecommander'
var logger = getLogger('main')

var telegramLink = require('telegram.link')()

// Prepare blessed UI

var screen = blessed.screen({
  smartCSR: true,
  dockBorders: true
})
screen.title = "Telecommander"

var defaultStyle = {
  fg: 'white',
  border: { fg: 'grey' },
  scrollbar: {
    ch: '*'
  }
}

// Contact list window
var chats = blessed.list({
  keys: true,
  label: 'Conversations',
  left: 0,
  top:0,
  height: screen.height-3,
  width: '20%',
  border: { type: 'line' },
  mouse: true,
  invertSelected: true,
  style: defaultStyle,
})
chats.style.item = { fg: 'grey' }
chats.style.selected = { fg: 'white' }
chats.focus()

// Function to create a log box
function mkBox(label){
  var box = blessed.log({
    keys: true,
    right: 0,
    label: label,
    width: '80%',
    height: screen.height - cmdline.height,
    border: { type: 'line' },
    scrollable: true,
    //draggable: true,
    style: defaultStyle
  })
  box.hide()
  return box
}

// Command line prompt
var cmdline = blessed.textbox({
  keys: true,
  label: 'Command for Telecommander',
  inputOnFocus: true,
  bottom: 0,
  left: 'center',
  width: '100%',
  height: 3,
  border: { type: 'line' },
  style: defaultStyle
})

var statusWindow = "Status"

// mgsBox holds the chat boxes for every list entry
var msgBox = { }
msgBox[statusWindow] = mkBox(statusWindow)

// Add stuff to the screen
screen.append(chats);
screen.append(cmdline);
screen.append(msgBox[statusWindow]);
chats.addItem(msgBox[statusWindow])
switchToBox(statusWindow)
screen.on('resize',function(){
  for(i in msgBox){
    item = msgBox[i]
    item.height = screen.height - cmdline.height
  }
  chats.height = screen.height - cmdline.height
  screen.render()
})
screen.key('tab',function(){
  screen.focusPush(chats)
})
screen.render()

// Contacts holds all the contacts data
var contacts = { }
// Groups hold all the data about groups
var groups = { }
// unameToUid is used to match a name to its user id
var unameToUid = { }
// same thing for group name -> group object
var gnameToGid = { }

var state = { } // keeps track of the telegram update state
var client // used to talk with telegram
var user = { } // holds data about current user
var authKey // our authorization key to access telegram
var connected = false // keep track of wether we are good to go and logged in
var selectedWindow = statusWindow // the currently selected window

// Write something in the Status box
function log(){
  args = Array.prototype.slice.call(arguments)
  var msg = args.join(' ')
  msgBox[statusWindow].add(msg)
  logger.info(msg)
}

function command(cmd){
  cmdl = cmd.split(' ')
  cmdname = cmdl[0]

  if(cmdname === 'phone'){ // So the user can provide his phone numbah
    if(connected){
      return log("Silly user, you're already connected! We don't need that phone number")
    }
    user.phone = cmd.split(' ')[1]
    var mindate = moment()
    log('Checking your phone number with Telegram...')
    client.auth.sendCode(user.phone,5,'en',function(result){
      if(result.err_code){
        return log('Errors:',result.error_code,result.error_message)
      }
      //log('Res:',JSON.stringify(result))
      user.registered = result.phone_registered
      user.phoneCodeHash = result.phone_code_hash
      function gmd(){
        var m = moment()
        m = m.subtract(m.diff(mindate))
        return 'Please use a telegram code not older than '+m.fromNow(true)
      }
      if(!user.registered){
        log("Your number is not registered. Telecommander will register your account with the Telegram service")
        log(gmd())
        log('Ready for phone code, use command: "code <code> <name> <lastname>" to register')
        log("If you don't want to sign up, just don't enter the code and press ESC to exit. No data was saved to the file system")
      } else {
        log("Your number is already assigned to a Telegram account. Telecommander will log you in.")
        log(gmd())
        log("If you don't want to sign in, just don't enter the code and press ESC to exit. No data was saved to the file system")
      }
    })

  } else if(cmdname === 'code'){ // So the user can provide his phone code
    if(connected){
      return log("Silly user, you're already connected! We don't need that phone code")
    }
    code = cmdl[1]
    name = cmdl[2]
    lastname = cmdl[3]
    if(((!name || !lastname) && !user.registered) || !code)
      return log('insufficient arguments:',cmd)
    cb = function(result){
      user.id = ''+result.user.id
      user.phone = result.user.phone
      user.phoneCodeHash = result.phone_code_hash
      user.username = result.user.username
      user.first_name = result.user.first_name
      user.last_name = result.user.last_name
      // Done, write user data and key to disk
      log('Writing Log In token and user data to',cfgDir)
      fs.writeFile(cfgDir+'key',authKey,function(err){
        if(err) log('FATAL: Could not write key to disk:',err)
      })
      fs.writeFile(cfgDir+'user_data.json',JSON.stringify(user),function(err){
        if(err) log("FATAL: couldn't write user_data.json:",err)
      })
      whenReady()
    }
    // Log in finally
    if(user.registered) client.auth.signIn(user.phone,user.phoneCodeHash,code,cb)
    else client.auth.signUp(user.phone,user.phoneCodeHash,code,name,lastname,cb)
  } else {
    log('Command not found.')
  }
}

// What happens when a different window is selected
chats.on('select',function(selected){
  log('SELECT:',selected.content)
  switchToBox(selected.content)
  screen.focusPush(cmdline)
  screen.render()
})

function switchToBox(boxname){
  if(selectedWindow && msgBox[selectedWindow])
    msgBox[selectedWindow].hide()
  selectedWindow = boxname;
  if(selectedWindow != statusWindow)
    cmdline.setLabel('to '+selectedWindow)
  else
    cmdline.setLabel('Command for Telecommander')
  var newb = getMsgBox(selectedWindow)
  newb.show()
}

// Get msgBox for given group/user NAME, create if not exists
function getMsgBox(chat,switchto){
  if(chat === undefined){
    log('ERROR: asked for box for "undefined"!!')
    return msgBox[statusWindow]
  }
  if(!msgBox[chat]){
    //log('Generating window: "'+chat+'"')
    msgBox[chat] = mkBox(chat)
    screen.append(msgBox[chat])
    getMessages(chat,msgBox[chat])
  } // else log('Getting window','"'+chat+'"')
  if(switchto === true){
    switchToBox(chat)
  }
  return msgBox[chat]
}

// What happens when the user submits a command in the prompt
cmdline.on('submit',function(value){
  msgBox[statusWindow].add('< '+value)
  if(selectedWindow === statusWindow || nameToObj(selectedWindow) === undefined){
    //log('Window:',selectedWindow,'Eval cmd:',value)
    command(value)
  } else if(value.indexOf('//') === 0){
    sendMsg(selectedWindow,value.substring(1))
  } else if(value.indexOf('/') === 0){
    command(value.substring(1))
  } else {
    sendMsg(selectedWindow,value)
  }
  cmdline.clearValue()
  cmdline.focus()
})

//cmdline.focus() // make sure prompt is focused

function quit(){
  if(connected || client != undefined){
    log('Closing communications and shutting down...')
    client.end(function(){
      process.exit(0)
    })
  } else process.exit(0);
}

// Catch ctrl-c or escape event and close program
screen.key(['escape','C-c'], function(ch,key){
  quit()
});

function nameToObj(name){
  var id = gnameToGid[name]
  if(groups[id] && groups[id].title === name)
    return groups[id]
  else {
    id = unameToUid[name]
    return contacts[id]
  }
}

function idToPeer(uid,type){
  if(type === 'user')
    return new telegramLink.type.InputPeerContact({ props: { user_id: ''+uid } })
  else if(type === 'group')
    return new telegramLink.type.InputPeerChat({ props: { chat_id: ''+uid } }) 
}

// Send a message
function sendMsg(name,str){
  if(!connected){
    return log('Error: not ready to send messages')
  }
  var peer = idToPeer(nameToObj(name).id,nameToObj(name).title?'group':'user')
  var randid = parseInt(Math.random() * 1000000000)
  //log('Sending Message to:',peer.toPrintable())
  client.messages.sendMessage(peer,str,randid,function(sent){
    //log('Sent message:','"'+str+'"','to:',selectedWindow+':',sent.toPrintable())
  })
}

// Connects to telegram
function connect(){
  client = telegramLink.createClient(app, telegramLink.PROD_PRIMARY_DC, function(){
    if(!app.authKey){
      log('Downloading Authorization Key...')
      client.createAuthKey(function(auth){
        authKey = auth.key.encrypt('password') // I know sorry, but I'm testing. Will add security later, I promise
        // Writes the new encrypted key to disk
        log('Ready for phone number, use command: phone <number>')
      })
    } else {
      whenReady()
    }
  })

  client.once('dataCenter',function(dcs){
    log('Datacenters:',dcs.toPrintable())
  })
}

// Executed when connected and logged in
function whenReady(){
  log('READY!')
  connected = true
  downloadData()
}

// Downloads stuff
function downloadData(){
  log('Downloading data...')
  client.contacts.getContacts('',function(cont){
    chats.clearItems()
    chats.add(statusWindow)
    cont.users.list.forEach(addUser)
  })

  client.messages.getDialogs(0,0,10,function(dialogs){
    if(dialogs && dialogs.chats && dialogs.chats.list)
      dialogs.chats.list.forEach(addGroup)
  })

  client.updates.getState(function(astate){
    updateState(astate)
    log(state.unreadCount,'unread messages')
    log('Started receiving updates')
    // Can't use registerOnUpdates because it's apparently broken
    //client.registerOnUpdates(onUpdate)
    setTimeout(downloadUpdates,1000)
  })
}

function addUser(u){
  contacts[u.id] = { user: u, id: u.id}
  var name = getName(u.id,'user')
  unameToUid[name] = u.id
  chats.addItem(name)
}

function addGroup(group){
  if(groups[group.id]) return;
  if(group.left === true) return;
  groups[group.id] = { id: group.id, title: group.title }
  gnameToGid[group.title] = group.id
  chats.addItem(group.title)
  log('Added group:',group.title)
}

// Updates the current state
function updateState(newstate){
  state.pts = newstate.pts
  state.qts = newstate.qts
  state.date = newstate.date
  state.sqp = newstate.seq
  state.unreadCount = newstate.unread_count
}

// process an update
function onUpdate(upd){
  log('Got Update:',upd.toPrintable())
}

function downloadUpdates(){
  client.updates.getDifference(state.pts,state.date,state.qts,function(res){
    if(!res.instanceOf('api.type.updates.DifferenceEmpty')){
      log('Got Diff: ',res.toPrintable())
      if(res.state){
        updateState(res.state)
      }
      if(res.new_messages){
        res.new_messages.list.forEach(function(msg){
          appendMsg(msg,undefined,false,true)
        })
      }
      if(res.chats){
        res.chats.list.forEach(function(c){
          if(!groups[c.id]){
            groups[c.id] = { id: c.id, title: c.title }
          }
        })
      }
    }
    setTimeout(downloadUpdates,1000)
  })
}

function nameForUser(u){
  return u.first_name + ' ' + u.last_name + (u.username?' (@'+u.username+')':'')
}

function getName(id,type){
  if(id === user.id) return nameForUser(user)
  else if(type === undefined) throw new Error('no type')
  else if(type === 'group' && groups[id])
    return groups[id].title
  else if(type === 'user' && contacts[id])
    return nameForUser(contacts[id].user)
  else log('Failed to find name for',type,id)
}

// Get message history with given name in the given box
function getMessages(name,box){
  if(!connected){
    return log('Uh cant get messages cuz not connected.....')
  }
  //log('Name to obj:',name)
  var obj = nameToObj(name)
  if(!obj || !obj.id){
    return log("Can't get messages",obj,obj.id,obj.title)
  }
  var type = obj.title?'group':'user'
  var peer = idToPeer(obj.id,type)
  box.add('Downloading message history for '+name)
  if(!peer) return log('Could not find peer:',name)
  client.messages.getHistory(peer,0,-1,20,function(res){
    //log(res.toPrintable())
    //log('Got history for: '+getName(peer.user_id||peer.chat_id,peer.chat_id?'group':'user'))
    if(!res.messages){
      return box.add(res.toPrintable())
    }
    res.messages.list.sort(function(msg1,msg2){
      return msg1.date - msg2.date
    })
    if(res.messages.list.length === 0)
      return appendToUserBox('No messages.',res)
    res.messages.list.forEach(function(msg){
      //if(!msg.message) return log('Empty message!',msg.toPrintable())
      //log('Scheduling message: '+msg.toPrintable())
      appendMsg(msg)
    })
  })
}

function appendToUserBox(msg,context){
  var goesto
  if(context.messages.list.length > 0){
    if(context.messages.list[0].to_id.chat_id){
      // Group message
      log('Chose',getName(context.messages.list[0].to_id.chat_id,'group'))
      goesto = getMsgBox(getName(context.messages.list[0].to_id.chat_id))
    }
  }
  if(goesto === undefined){
    if(context.users.list[0].user_id == user.id){
      goesto = getMsgBox(getName(context.users.list[1].id,'user'))
    } else{
      goesto = getMsgBox(getName(context.users.list[0].id,'user'))
    }
  }
  appendMsg(msg,goesto,true)
}

// Writes given telegram.link "message" object to given boxId
function appendMsg(msg,toBoxId,bare,smartmode){
  var box,param
  if(toBoxId != undefined){
    box = toBoxId
  } else {
    if(msg.to_id.chat_id != undefined){
      // Is a group
      param = getName(msg.to_id.chat_id,'group')
    } else if(msg.from_id === msg.to_id.user_id || msg.from_id != user.id){
      param = getName(msg.from_id,'user')
    } else if(msg.to_id.user_id != undefined && msg.to_id.user_id != user.id) {
      // don't forget dat .user_id! don't need it in from_id...
      param = getName(msg.to_id.user_id,'user')
    }
    if(smartmode && !bare){
      // Smart mode doesn't append the message to the box if it doesn't exist
      // because when created, the box will download message history
      if(msgBox[param] === undefined) return;
    }
    box = getMsgBox(param)
  }
  if(bare)
    box.add(msg)
  else {
    var from = msg.from_id
    var date = moment.unix(msg.date).fromNow()
    name = getName(from,'user')
    var txt
    if(msg.media){
      if(msg.media.photo)
        txt = ' <*> (Photo)'
      else if(msg.media.audio)
        txt = " <*> (Audio Message) "+msg.media.audio.duration+" seconds"
      else if(msg.message)
        txt = ' > '+msg.message
      else txt = " <*> (Unsupported Message)"
    }
    box.add(date+' | '+(name || from)+txt)
  }
}

// - Entry Point -
// Load authKey and userdata from disk, then act depending on outcome
var keyPath = cfgDir+'key'
log('Loading files...')
fs.exists(keyPath,function(exists){
  if(exists){
    //log('Authorization Key found')
    fs.readFile(keyPath,function(err,content){
      if(err)
        log('Error while reading key:',err)
      else {
        authKey = telegramLink.retrieveAuthKey(content,'password') // yeah sorry just testing
        app.authKey = authKey
        log('Authorization Key found')
        fs.readFile(cfgDir+'user_data.json',function(err,data){
          if(err)
            log("FATAL: couldn't read user_data.json")
          else {
            try {
              user = JSON.parse(data)
              log('Welcome',getName(user.id,'user'))
              connect()
            } catch (e) {
              log("FATAL: user data corrupted:",e)
            }
          }
        })
      }
    })
  } else {
    connect()
  }
})