LingrBot.scala

/**
Copyright (c) 2009 ymnk, JCraft,Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

   1. Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the distribution.

   3. The names of the authors may not be used to endorse or promote products
      derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
 INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io._
import scala.xml._
import scala.concurrent.ops.spawn
import scala.actors.Actor
import scala.actors.Actor.loop
import scala.collection.mutable.Map

object http{
  import java.net.URLEncoder.encode
  import java.net._

  private def param2str(param:(String,String)*):String =
    (for((k, v)<-param)
       yield k+"="+URLEncoder.encode(v, "UTF-8")).mkString("&")
  def post(uri:String, param:(String,String)*):Node={
    new URL(uri).openConnection match{
      case c:HttpURLConnection => {
        c.setDoInput(true)
        c.setDoOutput(true)
        c.setUseCaches(false)
        c.setRequestMethod("POST")
        c.setRequestProperty("Content-Type",
                             "application/x-www-form-urlencoded")
        val content = param2str(param:_*).getBytes
        c.setRequestProperty("Content-Length", content.length.toString);
        val o = c.getOutputStream
        o.write(content)
        o.flush
        o.close
        XML.load(c.getInputStream)
      }
    }
  }

  def get(uri:String, param:(String,String)*):Node={
    new URL(uri + "?" + param2str(param:_*)).openConnection match{
      case c:HttpURLConnection => {
        c.setRequestMethod("GET")
        XML.load(c.getInputStream)
      }
    }
  }
}

object LingrBot{
  abstract class Event
  case class Message(roomId:String,
                     nickname:String,
                     text:String) extends Event{
    var fromBot = false
  }
  case class Exit(roomId:String) extends Event
  case class Say(roomId:String, text:String) extends Event
}

class LingrBot(apiKey:String) extends Actor{
  import http.{get, post}
  import LingrBot._

  var nickname = "bot"

  val rooms = Map.empty[String, Room]

  private var handler:List[PartialFunction[Event,Unit]] = Nil
  def addHandler(h:PartialFunction[Event,Unit]){ handler = h::handler }

  private def create:String = {
    val response = post("http://www.lingr.com/api/session/create",
                        ("api_key" -> apiKey))
    response \\ "status" text match{
      case "ok" => response \\ "session" text
      case _ => throw new Exception("failed to get session id")
    }
  }

  val session = create

  def enterRoom(roomId:String)={
    val response = post("http://www.lingr.com/api/room/enter",
                        ("session" -> session),
                        ("id" -> roomId),
                        ("nickname" -> nickname))
    val r = new Room(roomId,
                     response \\ "ticket" text,
                     response \\ "occupant_id" text,
                     response \\ "counter" text)
    rooms += (roomId -> r)
    r
  }

  def observe(roomId:String){
    val r = enterRoom(roomId)
    spawn{
      var loop=true
      while(loop){
        rooms.get(roomId) match{
          case Some(_) => try{ r.observe }
            catch{case e:java.io.FileNotFoundException => }
          case _ => loop = false
        }
      }
    }
  }

  class Room(val roomId:String,
             val ticket:String, val my_occupant_id:String, 
             private var counter:String){

    private def setCounter(c:String)=synchronized{ if(c>=counter) counter=c }
    private def getCounter=synchronized{ counter }

    def observe {
      val counter = getCounter
      val response = get("http://www.lingr.com/api/room/observe",
                         ("session" -> session),
                         ("ticket" -> ticket),
                         ("counter" -> counter))

      response match {
        case <status>{ok}</status> =>
        case _ => {
          val _counter = response \\ "counter" text

          if(counter <= _counter){
            response \\ "messages" foreach {(m) =>
              val occupant_id = m \\ "occupant_id" text
              val nickname = m \\ "nickname" text
              val text = m \\ "text" text

              val _m = Message(roomId, nickname, text)
              _m.fromBot = occupant_id==my_occupant_id
              sendEvent(_m)

              setCounter(_counter)
            }
          }
          else{
          }
        }
      }
    }

    def say(message:String)={
      val response = post("http://www.lingr.com/api/room/say",
                         ("session" -> session),
                         ("ticket" -> ticket),
                         ("message" -> message))

      setCounter(response \\ "counter" text)
    }


    def exit={
      val response = post("http://www.lingr.com/api/room/say",
                         ("session" -> session),
                         ("ticket" -> ticket))

      if((response \\ "status" text) == "ok"){
        rooms -= roomId
      }
    }
  }

  private def sendEvent(event:Event){
    this ! event
  }

  def act = {
    loop {
      react {
        case e@Message(roomId, nickname, text) => if(!e.fromBot){
          handler.foreach{ (f) => if(f.isDefinedAt(e)) f(e) }
        }
        case Exit(roomId) => {
          rooms.get(roomId) match{
            case Some(room) => room.exit
            case _ =>
          }
        }
        case Say(roomId, text) => {
          rooms.get(roomId) match{
            case Some(room) => room.say(text)
            case _ =>
          }
        }
      }
    }
  }
}

object LingrBotTest{
  def main(arg:Array[String]){
    val Array(apiKey, roomId) = arg
    val bot = new LingrBot(apiKey)

    bot.addHandler({
      case LingrBot.Message(roomId, nickname, text) =>
        println(roomId+" | "+nickname+" | "+text)
    })

    bot.observe(roomId)
    bot.start

    var i = 0
    while(true){
      try{
        Thread.sleep(10000)
        bot ! LingrBot.Say(roomId, "hi! "+i)
        i += 1
      }
      catch{case e=> }
    }
  }
}