/* NSC -- new Scala compiler
 * Copyright 2002-2011 LAMP/EPFL
 * @author Martin Odersky
 */

package scala.tools.nsc
package reporters

import java.io.{ BufferedReader, IOException, PrintWriter }
import util._
import scala.tools.util.StringOps.countElementsAsString

/**
 * This class implements a Reporter that displays messages on a text
 * console.
 */
class ConsoleReporter(val settings: Settings, reader: BufferedReader, writer: PrintWriter) extends AbstractReporter {
  def this(settings: Settings) = this(settings, Console.in, new PrintWriter(Console.err, true))
  
  /** Whether a short file name should be displayed before errors */
  var shortname: Boolean = false

  /** maximal number of error messages to be printed */
  final val ERROR_LIMIT = 100

  private def label(severity: Severity): String = severity match {
    case ERROR   => "error"
    case WARNING => "warning"
    case INFO    => null
  }

  private def clabel(severity: Severity): String = {
    val label0 = label(severity)
    if (label0 eq null) "" else label0 + ": "
  }

  /** Returns the number of errors issued totally as a string.
   *
   *  @param severity ...
   *  @return         ...
   */
  private def getCountString(severity: Severity): String =
    countElementsAsString((severity).count, label(severity))

  /** Prints the message. */
  def printMessage(msg: String) { writer.print(msg + "\n"); writer.flush() }

  /** Prints the message with the given position indication. */
  def printMessage(posIn: Position, msg: String) {
    val pos = if (posIn eq null) NoPosition
              else if (posIn.isDefined) posIn.inUltimateSource(posIn.source)
              else posIn
    pos match {
      case FakePos(fmsg) =>
        printMessage(fmsg+" "+msg)
      case NoPosition =>
        printMessage(msg)
      case _ =>
        val buf = new StringBuilder(msg)
        val file = pos.source.file
        printMessage((if (shortname) file.name else file.path)+":"+pos.line+": "+msg)
        printSourceLine(pos)
    }
  }
  def print(pos: Position, msg: String, severity: Severity) {
    printMessage(pos, clabel(severity) + msg)
  }

  /**
   *  @param pos ...
   */
  def printSourceLine(pos: Position) {
    printMessage(pos.lineContent.stripLineEnd)
    printColumnMarker(pos)
  }

  /** Prints the column marker of the given position.
   *
   *  @param pos ...
   */
  def printColumnMarker(pos: Position) = 
    if (pos.isDefined) { printMessage(" " * (pos.column - 1) + "^") }
  
  /** Prints the number of errors and warnings if their are non-zero. */
  def printSummary() {
    if (WARNING.count > 0) printMessage(getCountString(WARNING) + " found")
    if (  ERROR.count > 0) printMessage(getCountString(ERROR  ) + " found")
  }

  def display(pos: Position, msg: String, severity: Severity) {
    severity.count += 1
    if (severity != ERROR || severity.count <= ERROR_LIMIT)
      print(pos, msg, severity)
  }

  def displayPrompt(): Unit = try {
    var continue = true
    while (continue) {
      writer.print("r)esume, a)bort: ")
      writer.flush()
      var line = reader.readLine()
      if (line ne null) {
	      line = line.toLowerCase()
	      if ("abort" startsWith line)
          abort("user abort")
	      if ("resume" startsWith line)
	        continue = false
      }
    }
  } 
  catch {
    case ex: IOException => {
      ex.printStackTrace()
      abort("input read error")
    }
  }

  private def abort(msg: String) = throw new Error(msg)
  override def flush() { writer.flush() }
}