import scala.actors.Actor
import scala.actors.Actor._
import java.util.Properties
import java.util.Date
import java.text.DateFormat
import java.text.SimpleDateFormat
import java.text.DecimalFormat
import java.io._
import javax.mail._
import javax.mail.internet._
import javax.mail.Flags.Flag

class Submission(email:String, labels:String) {
  val Email = email
  val Labels = labels
}


case class StudentRecord(ID:String, Email: String, BestAccuracy: Double, LastAccuracy: Double, BestSubmission: Date, NumOfSubmission: Int);


object Props {
  val trueLabelsFile = "D:/Users/Dropbox/Dropbox/TA/project1/test.labels.txt"
  val scoreSheetFile = "D:/Users/Dropbox/Dropbox/TA/project1/score-sheet.csv"
  val scoreWebPage = "D:/Users/Dropbox/Dropbox/Public/mail-judge/leaderboard_comp4331.html"
  val gmailAccount = "FILL GMAIL ACCOUNT"
  val gmailPassword = "FILL PASSWORD"
  val gmailAddress = gmailAccount + "@gmail.com"
  val checkSleep = 30000 // check email every 1 minute
  val dateFormat = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss")
  val accuracyFormat = new DecimalFormat("##.####")
}

case class Status(time:Date, ID:String, accuracy:Double);

object EmailJudger {
  val labelSource = scala.io.Source.fromFile(Props.trueLabelsFile)
  val trueLabels = labelSource.mkString.trim().split("\n").map(_.trim())
  
  val statusList = new scala.collection.mutable.ArrayBuffer[Status]()
  
  val restartDate = new Date()
  
  def main(args: Array[String]): Unit = {
    println("hello world")
    emailSenderActor.start()
    errorActor.start()
    parseEvalActor.start()
    
    def checkEmail() = {
      val props = System.getProperties()
      val session = Session.getInstance(props, null)
      val store = session.getStore("imaps")
      store.connect("imap.gmail.com", -1, Props.gmailAccount, Props.gmailPassword)
      val fod = store.getDefaultFolder()
      val folder = fod.getFolder("INBOX")
      folder.open(Folder.READ_WRITE)
      val totalMessages = folder.getMessageCount();
      var iter = totalMessages
      //var seencnt = 0
      while (iter>0) {
        val  msg = folder.getMessage(iter)
        if (msg.isSet(Flag.SEEN)) {
          //seencnt += 1
          //println(seencnt)
          //iter -= 1;
          //if (seencnt >20) {
          iter = 0
          // the bug seems due to "not pure message", a non-pure gives on error message
          //}
        }
        else {
          val date = msg.getReceivedDate()
          val from = msg.getFrom()(0).asInstanceOf[InternetAddress].getAddress()
          println(from)
          println(date)
          val p = msg.asInstanceOf[Part]
          var content = ""
          try {
            content = p.getContent().asInstanceOf[String]
            val sub = new Submission(from, content)
            
            parseEvalActor ! (sub, date)
          } catch {
            case e: ClassCastException =>
              msg.setFlag(Flag.SEEN, true)
              errorActor ! (from, "Your email body is not pure text")
          }
          
          iter -= 1
        }
      }
      store.close()
      
    }
    
    //emailSenderActor ! ("zhuyin.nju@gmail.com", "test, test")
    while (true) {
      println("check email")
      try {
    	  checkEmail()
      } catch {
        case e: javax.mail.MessagingException => {
          println(e.toString());
          println("Cannot connect to emailbox. But we roll on, get another try after several seconds")
          Thread.sleep(Props.checkSleep)
        }
        case e2: Exception => {
          println("I found a new exception which I cannot handle. sending a message to admin!")
          errorActor ! ("zhuyin.nju@gmail.com", "judge system error!\n\n" + e2.toString())
          throw e2;
        }
      }
      println("sleep")
      Thread.sleep(Props.checkSleep)
    }
  }
  
  val updateScoreSheetActor = actor {
    loop {
      receive {
        case (email:String, recDate:Date, accuracy:Double) => 
          val scoreSheetSource = scala.io.Source.fromFile(Props.scoreSheetFile)
          val lines = scoreSheetSource.mkString.trim().split("\n").map(_.trim())
          
          val records = 
	          lines.drop(1).map(
	        		  line => {
		            	val s = line.split(",")
		            	var date:Date = null
		            	try {
		            	  date = Props.dateFormat.parse(s(4))
		            	} catch {
		            	  case e:java.text.ParseException => 
		            	    {
		            	      date = null; // simple put null   
		            	    }
		            	}
		            	
						StudentRecord(s(0), s(1), s(2).toDouble, s(3).toDouble, date, s(5).toInt)
	        		  }
	          )
	      val idx = records.findIndexOf(r => r.Email == email)
	      
	      println("index of the email = " + idx.toString)
	      
	      if (idx == -1) {
	        println(email + " does not match emails in database")
	        errorActor ! (email, " your email address is not in our database")
	      }
	      else {
	          val oldrec = records(idx)
	          def max(x:Double, y:Double) = if (x>y) x else y
	          println(oldrec.ID + "  " + oldrec.NumOfSubmission)
	          //accuracy =  int(accuracy*10000)/10000
	          val acc4 = (accuracy*10000).toInt/10000.0
	          records(idx) =
	            if (oldrec.BestAccuracy >= acc4) 
	              StudentRecord(oldrec.ID, oldrec.Email, oldrec.BestAccuracy, acc4, oldrec.BestSubmission, oldrec.NumOfSubmission + 1)
	            else
                  StudentRecord(oldrec.ID, oldrec.Email, acc4, acc4, recDate, oldrec.NumOfSubmission + 1);
	          
	          statusList += Status(recDate, oldrec.ID, acc4)
	          
	          // write the csv file back
	          
	          def date2string(date:Date) = 
	            if (date == null) "-1"
	            else Props.dateFormat.format(date)
	          
	          def record2line (rec:StudentRecord) = 
	            (if (rec.ID.length() == 7) "0"+rec.ID else rec.ID)  + "," + rec.Email + "," +  Props.accuracyFormat.format(rec.BestAccuracy)  + ","  + Props.accuracyFormat.format(rec.LastAccuracy) + "," + date2string(rec.BestSubmission) + "," + rec.NumOfSubmission.toString()
	          
	          //println(record2line(records(idx)))
	                   
	          val fw2 = new FileWriter(Props.scoreSheetFile)
	          fw2.write("ID,EMAIL,Best-Accuracy,Last-Accuracy,Best-Submission-Date,NUM-OF-SUBMISSIONS\n")
	          records.foreach( rec => fw2.write(record2line(rec) + "\n"))
	          fw2.close()
	          
	          // update web page
	          
	          def record2webline (rec:StudentRecord) = 
	            	"<tr align=center>" + "<td>" + rec.ID + "</td><td>" + Props.accuracyFormat.format(rec.BestAccuracy) + "</td><td>" + Props.accuracyFormat.format(rec.LastAccuracy) + "</td><td>"+ date2string(rec.BestSubmission) + "</td><td>"+rec.NumOfSubmission.toString() + "</td></tr>\n"
	
	          //val sortedRecords = records.sortBy(rec => (- rec.BestAccuracy, rec.BestSubmission)) // sort by accuracy and the last submission time
	          val sortedRecords = records.sortBy(rec => (- rec.BestAccuracy))
	          val fw = new FileWriter(Props.scoreWebPage)
	          fw.write("<html><body>\n")
	          fw.write("Last updated on " + (new Date()).toString() + "<br><br><br>\n")
	          
	          fw.write("The email judge is restarted at " + Props.dateFormat.format(restartDate) + ".<br> ")
	          fw.write("Last few submissions:<br>")
	          
	          var last = statusList.size - 1
	          while (last >= 0 && last > statusList.size - 5) {
	            fw.write(date2string(statusList(last).time) + "&nbsp; &nbsp; &nbsp;")
	            fw.write(statusList(last).ID + "&nbsp; &nbsp; &nbsp;")
	            fw.write(Props.accuracyFormat.format(statusList(last).accuracy) + "<br>\n")
	            last = last - 1
	          }
	          
	          fw.write("<br><br><br>")
	          fw.write("<table align=\"centered\" border=\"1\">")
	          fw.write(
	          		"<tr  align=center> <th>ID</th> <th>Best-Accuracy</th> <th>Last-Accuracy</th> <th>Best-Submission-Date </th> <th>Number-of-submissions</th> </tr>"
	              );
	          
	          //fw.write("ID,Best-Accuracy,Last-Accuracy,Number-of-submissions <br>\n")
	          sortedRecords.filter(rec => rec.BestAccuracy > 0).foreach( rec => fw.write(record2webline(rec) + "\n"))
	          
	          fw.write("</table> </body></html>")
	          fw.close()
	      }
      }
    }
  }
  
  val emailSenderActor = actor {
    loop {
      receive {
        case (emailTo:java.lang.String, content:String) => {
          val props = System.getProperties()
          props.put("mail.smtp.host", "smtp.gmail.com")
          val session = Session.getInstance(props, null);
          val msg = new MimeMessage(session);
          msg.setFrom(new InternetAddress(Props.gmailAddress))
          msg.setRecipients(Message.RecipientType.TO, 
              InternetAddress.parse(emailTo, false).asInstanceOf[Array[Address]])
          msg.setText(content)
          msg.setHeader("X-Mailer", "robot")
          msg.setSentDate(new Date())
          
          val t = session.getTransport("smtps")
          t.connect("smtp.gmail.com", Props.gmailAccount, Props.gmailPassword)
          t.sendMessage(msg, msg.getAllRecipients())
          t.close()
        }
      }
    }
  }
  
  
  val errorActor = actor {
    loop {
      receive {
        case (email: String, msg: String) => 
          {
            emailSenderActor ! (email, "ERROR: " + msg)
          }
      }
    }
  }
  
  
  
  val parseEvalActor = actor {
	loop {
	  receive {
	    case (sub:Submission, date:Date) => 
	      val email = sub.Email
	      val labels = sub.Labels.trim().split("\n") map (_.trim())
	      if (trueLabels.length != labels.length)
	      {
	        errorActor ! (sub.Email, "your submission does not contain 30,000 lines EXACTLY.")
	      }
	      else if (labels.exists(line => if (line != "O0" && line != "O1") true else false)) {
	        errorActor ! (sub.Email, "your email body contains strings other than O0 and O1")
	      }
	      else {
		      val correct = labels zip trueLabels map( pair => if (pair._1 == pair._2) 1 else 0) sum
		      val n = labels.length
		      val accuracy = correct * 1.0 / n
		      
		      // send email to the student
		      emailSenderActor ! (email, "your accuracy for this submission is " + accuracy.toString() +
		          "\n\n" + "please check the latest leaderboard at: http://dl.dropbox.com/u/7090102/mail-judge/leaderboard_comp4331.html")
		      println("your accuracy for this submission is " + accuracy.toString())
		      
		      // update the webpage
		      updateScoreSheetActor ! (email, date, accuracy)
	      }
      }
	}
  }
  
  
}