/* NSC -- new Scala compiler
 * Copyright 2005-2006 LAMP/EPFL
 * @author  Martin Odersky
 */
// $Id$

package scala.tools.nsc

import java.io._
import java.nio.charset._
import scala.tools.nsc.io.{SourceReader, AbstractFile}
import scala.tools.nsc.util.ClassPath
import scala.tools.nsc.util.{Position, SourceFile}
import scala.tools.nsc.reporters._

import scala.collection.mutable.{HashSet, HashMap, ListBuffer}

import symtab._
import symtab.classfile.{PickleBuffer, Pickler}
import util.Statistics
import ast._
import ast.parser._
import typechecker._
import matching.TransMatcher
import transform._
import backend.icode.{ICodes, GenICode, Checkers}
import backend.ScalaPrimitives
import backend.jvm.GenJVM
import backend.opt.{Inliners, ClosureElimination, DeadCodeElimination}
import backend.icode.analysis._

class Global(val settings: Settings, val reporter: Reporter) extends SymbolTable
                                                             with Trees
                                                             with CompilationUnits
{

  // sub-components --------------------------------------------------

  object treePrinters extends TreePrinters {
    val global: Global.this.type = Global.this
  }
  val treePrinter = treePrinters.create();

  object treeBrowsers extends TreeBrowsers {
    val global: Global.this.type = Global.this
  }
  val treeBrowser = treeBrowsers.create();

  object treeInfo extends TreeInfo {
    val global: Global.this.type = Global.this
  }

  object gen extends TreeGen {
    val global: Global.this.type = Global.this
  }

  object constfold extends ConstantFolder {
    val global: Global.this.type = Global.this
  }

  object checker extends TreeCheckers {
    val global: Global.this.type = Global.this
  }

  object icodes extends ICodes {
    val global: Global.this.type = Global.this
  }

  object analysis extends TypeFlowAnalysis {
    val global: Global.this.type = Global.this;
  }

  object copyPropagation extends CopyPropagation {
    val global: Global.this.type = Global.this;
  }

  object checkers extends Checkers {
    val global: Global.this.type = Global.this
  }

  object statistics extends Statistics {
    val global: Global.this.type = Global.this
  }

  object overridingPairs extends OverridingPairs {
    val global: Global.this.type = Global.this
  }

  val copy = new LazyTreeCopier();

  val comments =
    if (onlyPresentation) new HashMap[Symbol,String];
    else null;

// reporting -------------------------------------------------------

  def error(msg: String) = reporter.error(null, msg)
  def warning(msg: String) = reporter.warning(null, msg)
  def inform(msg: String) = System.err.println(msg)
  def inform[T](msg: String, value: T): T = { inform(msg+value); value }

  //reporter.info(null, msg, true);
  def informProgress(msg: String) =
    if (settings.verbose.value) inform("[" + msg + "]")

  def informTime(msg: String, start: Long) =
    informProgress(msg + " in " + (System.currentTimeMillis() - start) + "ms")

  def log(msg: Object): unit =
    if (settings.log contains phase.name) inform("[log " + phase + "] " + msg)

  class ErrorWithPosition(val pos: Int, val error: Throwable) extends Error

  def tryWith[T](pos: Int, body: => T): T = try {
    body
  } catch {
    case e : ErrorWithPosition => throw e
    case te: TypeError => throw te
    case e : Error            => throw new ErrorWithPosition(pos, e)
    case e : RuntimeException => throw new ErrorWithPosition(pos, e)
  }
  def catchWith[T](source : SourceFile, body : => T) : T = try {
    body
  } catch {
    case e : ErrorWithPosition =>
      logError("POS: " + source.dbg(e.pos), e);
      throw e.error
  }

  def logError(msg: String, t: Throwable): Unit = {}

  def abort(msg: String) = throw new Error(msg)

// file interface -------------------------------------------------------

  private val reader: SourceReader = {
    def stdCharset: Charset = {
      settings.encoding.value = "ISO-8859-1"; // A mandatory charset
      Charset.forName(settings.encoding.value)
    }
    val charset =
      try {
        Charset.forName(settings.encoding.value)
      } catch {
        case _: IllegalCharsetNameException =>
          error("illegal charset name '" + settings.encoding.value + "'")
          stdCharset
        case _: UnsupportedCharsetException =>
          error("unsupported charset '" + settings.encoding.value + "'")
          stdCharset
      }
    new SourceReader(charset.newDecoder());
  }

  val classPath0 = new ClassPath(onlyPresentation)

  val classPath = new classPath0.Build(
    settings.classpath.value,
    settings.sourcepath.value,
    settings.outdir.value,
    settings.bootclasspath.value,
    settings.extdirs.value);

  if (settings.verbose.value) {
    System.err.println("classpath = " + classPath)
  }

  def getSourceFile(f: AbstractFile): SourceFile =
    new SourceFile(f, reader.read(f))

  def getSourceFile(name: String): SourceFile = {
    val f = AbstractFile.getFile(name)
    if (f == null) throw new FileNotFoundException(
      "source file '" + name + "' could not be found");
    getSourceFile(f)
  }

  def getSourceFile(clazz: Symbol): SourceFile = {
    val ret = classPath.root.find(clazz.fullNameString(File.separatorChar), false)
    if (!ret.isSourceFile) throw new FileNotFoundException(
      "source file for " + clazz + " could not be found");
    getSourceFile(ret.sourceFile)
  }

  object loaders extends SymbolLoaders {
    val global: Global.this.type = Global.this
  }

  def rootLoader: LazyType = new loaders.PackageLoader(classPath.root /* getRoot() */)

  val migrateMsg = "migration problem when moving from Scala version 1.0 to version 2.0:\n";

// Phases ------------------------------------------------------------

  var globalPhase: Phase = NoPhase

  val MaxPhases = 64

  val phaseWithId = new Array[Phase](MaxPhases);
  { for (val i <- List.range(0, MaxPhases)) phaseWithId(i) = NoPhase }

  abstract class GlobalPhase(prev: Phase) extends Phase(prev) {
    phaseWithId(id) = this
    def run: unit = currentRun.units foreach applyPhase;

    def apply(unit: CompilationUnit): unit;
    private val isErased = prev.name == "erasure" || prev.erasedTypes;
    override def erasedTypes: boolean = isErased;
    private val isFlat = prev.name == "flatten" || prev.flatClasses;
    override def flatClasses: boolean = isFlat;
    final def applyPhase(unit: CompilationUnit): unit = {
      if (settings.debug.value) inform("[running phase " + name + " on " + unit + "]");
      val unit0 = currentRun.currentUnit;
      currentRun.currentUnit = unit;
      apply(unit);
      currentRun.advanceUnit;
      assert(currentRun.currentUnit == unit);
      currentRun.currentUnit = unit0;
    }
  }

  object syntaxAnalyzer extends SyntaxAnalyzer {
    val global: Global.this.type = Global.this
  }

  object analyzer extends Analyzer {
    val global: Global.this.type = Global.this
  }

  object superAccessors extends SuperAccessors {
    val global: Global.this.type = Global.this
  }

  object pickler extends Pickler {
    val global: Global.this.type = Global.this
  }

  object refchecks extends RefChecks {
    val global: Global.this.type = Global.this
  }

  object liftcode extends LiftCode {
    val global: Global.this.type = Global.this
  }

  object uncurry extends UnCurry {
    val global: Global.this.type = Global.this
  }

  object tailCalls extends TailCalls {
    val global: Global.this.type = Global.this
  }

  object transMatcher extends TransMatcher {
    val global: Global.this.type = Global.this
  }

//  object checkDefined extends CheckDefined {
//    val global: Global.this.type = Global.this
//  }

  object explicitOuter extends ExplicitOuter {
    val global: Global.this.type = Global.this
  }

  object erasure extends Erasure {
    val global: Global.this.type = Global.this
  }

  object lambdaLift extends LambdaLift {
    val global: Global.this.type = Global.this
  }

  object constructors extends Constructors {
    val global: Global.this.type = Global.this
  }

  object flatten extends Flatten {
    val global: Global.this.type = Global.this
  }
/*
  object detach extends Detach {
    val global: Global.this.type = Global.this
  }
*/
  object mixer extends Mixin {
    val global: Global.this.type = Global.this
  }

  object cleanup extends CleanUp {
    val global: Global.this.type = Global.this
  }

  object sampleTransform extends SampleTransform {
    val global: Global.this.type = Global.this
  }

  object genicode extends GenICode {
    val global: Global.this.type = Global.this
  }

  object icodePrinter extends backend.icode.Printers {
    val global: Global.this.type = Global.this
  }

  object scalaPrimitives extends ScalaPrimitives {
    val global: Global.this.type = Global.this
  }

  object inliner extends Inliners {
    val global: Global.this.type = Global.this
  }

  object closureElimination extends ClosureElimination {
    val global: Global.this.type = Global.this
  }

  object deadCode extends DeadCodeElimination {
    val global: Global.this.type = Global.this
  }

  object genJVM extends GenJVM {
    val global: Global.this.type = Global.this
  }

  object icodeChecker extends checkers.ICodeChecker()

  object typer extends analyzer.Typer(
    analyzer.NoContext.make(EmptyTree, Global.this.definitions.RootClass, new Scope()))

  def phaseDescriptors: List[SubComponent] = List(
    analyzer.namerFactory,
    analyzer.typerFactory,
    superAccessors,
    pickler,
    refchecks,
    liftcode,
    uncurry,
    tailCalls,
    transMatcher,
//    checkDefined,
    explicitOuter,
    erasure,
    lambdaLift,
    constructors,
    flatten,
    mixer,
    cleanup,
    genicode,
    inliner,
    closureElimination,
    deadCode,
    genJVM,
    sampleTransform);

  protected def insertBefore(c: SubComponent, cs: List[SubComponent], before: SubComponent): List[SubComponent] = cs match {
    case List() => List(c)
    case c1 :: cs1 => if (c1 == before) c :: cs else c1 :: insertBefore(c, cs1, before)
  }

  private var curRun: Run = NoRun
  override def currentRun: Run = curRun

  def onlyPresentation = settings.doc.value

  def forCLDC: Boolean = settings.target.value == "cldc"

  class Run extends CompilerRun {
    var currentUnit: CompilationUnit = _
    curRun = this
    override val firstPhase = syntaxAnalyzer.newPhase(NoPhase);
    phase = firstPhase;
    definitions.init; // needs firstPhase and phase to be defined != NoPhase,
                      // that's why it is placed here.
    icodes.init;

    private var p: Phase = firstPhase
    private var stopped = false
    for (val pd <- phaseDescriptors) {
      if (!stopped) {
        if (!(settings.skip contains pd.phaseName)) p = pd.newPhase(p);
        stopped = settings.stop contains pd.phaseName
      }
    }
    // progress tracking
    def progress(current: Int, total: Int): Unit = {}

    private var phasec: Int = 0
    private var unitc: Int = 0
    def advancePhase: Unit = {
      unitc = 0
      phasec = phasec + 1
      refreshProgress
    }
    def advanceUnit: Unit = {
      unitc = unitc + 1
      refreshProgress
    }
    private def refreshProgress = if (fileset.size > 0)
      progress((phasec * fileset.size) + unitc,
               (phaseDescriptors.length+1) * fileset.size);

    override def phaseNamed(name: String): Phase = {
      var p: Phase = firstPhase
      while (p.next != p && p.name != name) p = p.next;
      if (p.name != name) NoPhase else p
    }

    override val namerPhase = phaseNamed("namer")
    override val typerPhase = phaseNamed("typer")
    override val refchecksPhase = phaseNamed("refchecks")

    override val explicitOuterPhase = phaseNamed("explicitouter")
    override val erasurePhase = phaseNamed("erasure")
    override val flattenPhase = phaseNamed("flatten")
    override val mixinPhase = phaseNamed("mixin")
    override val icodePhase = phaseNamed("icode")

    private var unitbuf = new ListBuffer[CompilationUnit];
    private var fileset = new HashSet[AbstractFile];

    override val terminalPhase : Phase =
      if (onlyPresentation) typerPhase.next.next
      else /* new GlobalPhase(p) {
        def name = "terminal"
        def apply(unit: CompilationUnit): unit = {}
      }*/ p;

    private def addUnit(unit: CompilationUnit): unit = {
      unitbuf += unit
      fileset += unit.source.getFile()
    }

    def units: Iterator[CompilationUnit] = unitbuf.elements

    /** A map from compiled top-level symbols to their source files */
    val symSource = new HashMap[Symbol, AbstractFile]

    /** A map from compiled top-level symbols to their picklers */
    val symData = new HashMap[Symbol, PickleBuffer]

    /** does this run compile given class, module, or case factory? */
    def compiles(sym: Symbol): boolean =
      if (sym == NoSymbol) false
      else if (symSource.isDefinedAt(sym)) true
      else if (!sym.owner.isPackageClass) compiles(sym.toplevelClass)
      else if (sym.isModuleClass) compiles(sym.sourceModule)
      else false;

    def compileSources(sources: List[SourceFile]): unit = {
      val startTime = System.currentTimeMillis();
      reporter.reset
      for (val source <- sources)
        addUnit(new CompilationUnit(source));

      globalPhase = firstPhase
      while (globalPhase != terminalPhase && reporter.errors == 0) {
        val startTime = System.currentTimeMillis();
        phase = globalPhase;
        globalPhase.run;
        if (settings.print contains globalPhase.name)
          if (globalPhase.id >=  icodePhase.id) writeICode()
          else treePrinter.printAll();
        if (settings.browse contains globalPhase.name) treeBrowser.browse(units);
        informTime(globalPhase.description, startTime);
        globalPhase = globalPhase.next;
        if (settings.check contains globalPhase.name) {
          phase = globalPhase;
          if (globalPhase.id >= icodePhase.id) icodeChecker.checkICodes;
          else checker.checkTrees;
        }
        if (settings.statistics.value) statistics.print(phase);
        advancePhase
      }

      if (settings.Xshowcls.value != "") showDef(newTermName(settings.Xshowcls.value), false);
      if (settings.Xshowobj.value != "") showDef(newTermName(settings.Xshowobj.value), true);

      if (reporter.errors == 0) {
        assert(stopped || symData.isEmpty, symData.elements.toList);
      } else {
        for (val Pair(sym, file) <- symSource.elements) {
          sym.reset(new loaders.SourcefileLoader(file));
          if (sym.isTerm) sym.moduleClass.reset(loaders.moduleClassLoader);
        }
      }
      for (val Pair(sym, file) <- symSource.elements) resetPackageClass(sym.owner);
      informTime("total", startTime)
    }

    def compileLate(file: AbstractFile): unit =
      if (fileset == null) {
        val msg = "No class file for " + file +
                  " was found\n(This file cannot be loaded as a source file)";
        System.err.println(msg)
        throw new FatalError(msg)
      }
      else if (!(fileset contains file)) {
        val unit = new CompilationUnit(getSourceFile(file));
        addUnit(unit);
        var localPhase = firstPhase.asInstanceOf[GlobalPhase];
        while ((localPhase.id < globalPhase.id || localPhase.id <= namerPhase.id) &&
            reporter.errors == 0) {
          atPhase(localPhase)(localPhase.applyPhase(unit));
          localPhase = localPhase.next.asInstanceOf[GlobalPhase];
        }
        refreshProgress
      }

    def compileFiles(files: List[AbstractFile]): unit =
      try {
        compileSources(files map getSourceFile)
      } catch {
        case ex: IOException => error(ex.getMessage())
      }

    def compile(filenames: List[String]): unit =
      try {
        compileSources(filenames map getSourceFile)
      } catch {
        case ex: IOException => error(ex.getMessage())
      }

    private def resetPackageClass(pclazz: Symbol): unit = {
      assert(pclazz.isPackageClass, pclazz);
      atPhase(firstPhase) {
        pclazz.setInfo(atPhase(typerPhase)(pclazz.info))
      }
      if (!pclazz.isRoot) resetPackageClass(pclazz.owner)
    }
  } // class Run

  def showDef(name: Name, module: boolean): unit = {
    def getSym(name: Name, module: boolean): Symbol = {
      var i = name.length - 1
      while (i != 0 && name(i) != '#' && name(i) != '.') i = i - 1
      if (i == 0)
        definitions.getModule(name)
      else {
        val root = getSym(name.subName(0, i), name(i) == '.')
        var selector = name.subName(i+1, name.length)
        if (module) selector = selector.toTypeName
        root.info.member(selector)
      }
    }
    val sym = getSym(name, module);
    System.err.println("" + sym.name + ":" +
                       (if (module) sym.tpe.symbol.info else sym.info))
  }

  /** Returns the file with the given suffix for the given class. */
  def getFile(clazz: Symbol, suffix: String) = {
    val outdirname = settings.outdir.value
    var outdir = new File(if (outdirname == "") "." else outdirname)
    val filename = clazz.fullNameString('.')
    var start = 0
    var end = filename.indexOf('.', start)
    while (end >= start) {
      outdir = new File(outdir, filename.substring(start, end));
      if (!outdir.exists()) outdir.mkdir();
      start = end + 1;
      end = filename.indexOf('.', start)
    }
    new File(outdir, filename.substring(start) + suffix)
  }

  private def writeSymblFile(clazz: Symbol, pickled: PickleBuffer) = {
    val file = getFile(clazz, ".symbl")
    try {
      val stream = new FileOutputStream(file);
      stream.write(pickled.bytes, 0, pickled.writeIndex);
      stream.close();
      informProgress("wrote " + file)
    } catch {
      case ex: IOException =>
      if (settings.debug.value) ex.printStackTrace();
      error("could not write file " + file)
    }
  }

  private def writeICode(): Unit = {
    val printer = new icodePrinter.TextPrinter(null, icodes.linearizer);
    icodes.classes.values.foreach((cls) => {
      val suffix = if (cls.symbol.hasFlag(Flags.MODULE)) "$.icode" else ".icode";
      var file = getFile(cls.symbol, suffix);
//      if (file.exists())
//        file = new File(file.getParentFile(), file.getName() + "1");
      try {
        val stream = new FileOutputStream(file);
        printer.setWriter(new PrintWriter(stream, true));
        printer.printClass(cls);
        informProgress("wrote " + file);
      } catch {
        case ex: IOException =>
          if (settings.debug.value) ex.printStackTrace();
        error("could not write file " + file);
      }
    });
  }

}