/*
 * Copyright 2000-2014 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jetbrains.java.decompiler.main;

import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
import org.jetbrains.java.decompiler.main.rels.ClassWrapper;
import org.jetbrains.java.decompiler.main.rels.MethodWrapper;
import org.jetbrains.java.decompiler.modules.decompiler.exps.Exprent;
import org.jetbrains.java.decompiler.modules.decompiler.exps.InvocationExprent;
import org.jetbrains.java.decompiler.modules.decompiler.exps.NewExprent;
import org.jetbrains.java.decompiler.modules.decompiler.exps.VarExprent;
import org.jetbrains.java.decompiler.modules.decompiler.stats.Statement;
import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPaar;
import org.jetbrains.java.decompiler.struct.StructClass;
import org.jetbrains.java.decompiler.struct.StructField;
import org.jetbrains.java.decompiler.struct.StructMethod;
import org.jetbrains.java.decompiler.struct.gen.FieldDescriptor;
import org.jetbrains.java.decompiler.struct.gen.VarType;
import org.jetbrains.java.decompiler.util.InterpreterUtil;

public class EnumProcessor {

  public static void clearEnum(ClassWrapper wrapper) {

    StructClass cl = wrapper.getClassStruct();

    // hide values() and valueOf()
    for (StructMethod meth : cl.getMethods()) {

      String name = meth.getName();
      int flag = 0;

      if ("values".equals(name)) {
        flag = 1;
      }
      else if ("valueOf".equals(name)) {
        flag = 2;
      }

      if (flag > 0) {
        String[] arr = meth.getDescriptor().split("[()]");
        String par = arr[1];

        if ((flag == 1 && par.length() == 0) ||
            flag == 2 && "Ljava/lang/String;".equals(par)) {
          wrapper.getHideMembers().add(InterpreterUtil.makeUniqueKey(name, meth.getDescriptor()));
        }
      }
    }

    // hide all super invocations
    for (MethodWrapper meth : wrapper.getMethods()) {
      if ("<init>".equals(meth.methodStruct.getName())) {
        Statement firstdata = findFirstData(meth.root);
        if (firstdata == null || firstdata.getExprents().isEmpty()) {
          return;
        }

        Exprent exprent = firstdata.getExprents().get(0);
        if (exprent.type == Exprent.EXPRENT_INVOCATION) {
          InvocationExprent invexpr = (InvocationExprent)exprent;
          if (isInvocationSuperConstructor(invexpr, meth, wrapper)) {
            firstdata.getExprents().remove(0);
          }
        }
      }
    }

    // hide dummy synthetic fields of enum constants
    for (StructField fd : cl.getFields()) {
      if ((fd.access_flags & CodeConstants.ACC_ENUM) != 0) {
        Exprent initializer =
          wrapper.getStaticFieldInitializers().getWithKey(InterpreterUtil.makeUniqueKey(fd.getName(), fd.getDescriptor()));
        if (initializer != null && initializer.type == Exprent.EXPRENT_NEW) {
          NewExprent nexpr = (NewExprent)initializer;
          if (nexpr.isAnonymous()) {
            ClassNode child = DecompilerContext.getClassProcessor().getMapRootClasses().get(nexpr.getNewtype().value);
            hideDummyFieldInConstant(child.wrapper);
          }
        }
      }
    }
  }

  private static void hideDummyFieldInConstant(ClassWrapper wrapper) {

    StructClass cl = wrapper.getClassStruct();
    for (StructField fd : cl.getFields()) {
      if ((fd.access_flags & CodeConstants.ACC_SYNTHETIC) != 0) {
        FieldDescriptor descr = FieldDescriptor.parseDescriptor(fd.getDescriptor());
        VarType ret = descr.type;

        if (ret.type == CodeConstants.TYPE_OBJECT && ret.arraydim == 1 && cl.qualifiedName.equals(ret.value)) {
          wrapper.getHideMembers().add(InterpreterUtil.makeUniqueKey(fd.getName(), fd.getDescriptor()));
        }
      }
    }
  }

  // FIXME: move to a util class (see also InitializerProcessor)
  private static Statement findFirstData(Statement stat) {

    if (stat.getExprents() != null) {
      return stat;
    }
    else {
      if (stat.isLabeled()) {
        return null;
      }

      switch (stat.type) {
        case Statement.TYPE_SEQUENCE:
        case Statement.TYPE_IF:
        case Statement.TYPE_ROOT:
        case Statement.TYPE_SWITCH:
        case Statement.TYPE_SYNCRONIZED:
          return findFirstData(stat.getFirst());
        default:
          return null;
      }
    }
  }

  // FIXME: move to util class (see also InitializerProcessor)
  private static boolean isInvocationSuperConstructor(InvocationExprent inv, MethodWrapper meth, ClassWrapper wrapper) {

    if (inv.getFunctype() == InvocationExprent.TYP_INIT) {
      if (inv.getInstance().type == Exprent.EXPRENT_VAR) {
        VarExprent instvar = (VarExprent)inv.getInstance();
        VarVersionPaar varpaar = new VarVersionPaar(instvar);

        String classname = meth.varproc.getThisvars().get(varpaar);

        if (classname != null) { // any this instance. TODO: Restrict to current class?
          if (!wrapper.getClassStruct().qualifiedName.equals(inv.getClassname())) {
            return true;
          }
        }
      }
    }

    return false;
  }
}