/* FieldOperator Copyright (C) 1998-2002 Jochen Hoenicke.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; see the file COPYING.LESSER.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id$
 */

package net.sf.jode.expr;
import net.sf.jode.type.Type;
import net.sf.jode.type.NullType;
import net.sf.jode.type.ClassInfoType;
import net.sf.jode.bytecode.FieldInfo;
import net.sf.jode.bytecode.ClassInfo;
import net.sf.jode.bytecode.ClassPath;
import net.sf.jode.bytecode.Reference;
import net.sf.jode.bytecode.TypeSignature;
import net.sf.jode.decompiler.MethodAnalyzer;
import net.sf.jode.decompiler.ClassAnalyzer;
import net.sf.jode.decompiler.FieldAnalyzer;
import net.sf.jode.decompiler.Options;
import net.sf.jode.decompiler.TabbedPrintWriter;
import net.sf.jode.decompiler.Scope;

import java.io.IOException;
import java.lang.reflect.Modifier;
///#def COLLECTIONS java.util
import java.util.Collection;
///#enddef

/**
 * This class contains everything shared between PutFieldOperator and
 * GetFieldOperator
 */
public abstract class FieldOperator extends Operator {
    MethodAnalyzer methodAnalyzer;
    boolean staticFlag;
    Reference ref;
    Type classType;
    ClassInfo classInfo;
    ClassPath classPath;
    String callerPackage;

    public FieldOperator(MethodAnalyzer methodAnalyzer, boolean staticFlag,
			 Reference ref) {
        super(Type.tUnknown);

	this.classPath = methodAnalyzer.getClassAnalyzer().getClassPath();

        this.methodAnalyzer = methodAnalyzer;
        this.staticFlag = staticFlag;
	this.type = Type.tType(classPath, ref.getType());
        this.classType = Type.tType(classPath, ref.getClazz());
	this.ref = ref;
        if (staticFlag)
            methodAnalyzer.useType(classType);
	initOperands(staticFlag ? 0 : 1);

	callerPackage = methodAnalyzer.getClassAnalyzer().getClass().getName();
	int dot = callerPackage.lastIndexOf('.');
	callerPackage = callerPackage.substring(0, dot);
	if (classType instanceof ClassInfoType) {
	    classInfo = ((ClassInfoType) classType).getClassInfo();
	    if ((Options.options & Options.OPTION_ANON) != 0
		|| (Options.options & Options.OPTION_INNER) != 0) {
		try {
		    classInfo.load(ClassInfo.OUTERCLASS);
		} catch (IOException ex) {
		    classInfo.guess(ClassInfo.OUTERCLASS);
		}
	    }
	}
    }

    public int getPriority() {
        return 950;
    }

    public void updateSubTypes() {
	if (!staticFlag)
	    subExpressions[0].setType(Type.tSubType(classType));
    }

    public void updateType() {
	updateParentType(getFieldType());
    }

    public boolean isStatic() {
        return staticFlag;
    }

    public ClassInfo getClassInfo() {
	return classInfo;
    }

    /**
     * Returns the field analyzer for the field, if the field is
     * declared in the same class or some outer class as the method
     * containing this instruction.  Otherwise it returns null.
     * @return see above.  
     */
    public FieldAnalyzer getField() {
	ClassInfo clazz = classInfo;
	if (clazz != null) {
	    ClassAnalyzer ana = methodAnalyzer.getClassAnalyzer();
	    while (true) {
		if (clazz == ana.getClazz()) {
		    int field = ana.getFieldIndex
			(ref.getName(), Type.tType(classPath, ref.getType()));
		    if (field >= 0)
			return ana.getField(field);
		    return null;
		}
		if (ana.getParent() == null)
		    return null;
		if (ana.getParent() instanceof MethodAnalyzer)
		    ana = ((MethodAnalyzer) ana.getParent())
			.getClassAnalyzer();
		else if (ana.getParent() instanceof ClassAnalyzer)
		    ana = (ClassAnalyzer) ana.getParent();
		else 
		    throw new InternalError("Unknown parent");
	    }
	}
	return null;
    }

    public String getFieldName() {
        return ref.getName();
    }

    public Type getFieldType() {
        return Type.tType(classPath, ref.getType());
    }

    private static FieldInfo getFieldInfo(ClassInfo clazz, 
					  String name, String type) {
	while (clazz != null) {
	    FieldInfo field = clazz.findField(name, type);
	    if (field != null)
		return field;

	    ClassInfo[] ifaces = clazz.getInterfaces();
	    for (int i = 0; i < ifaces.length; i++) {
		field = getFieldInfo(ifaces[i], name, type);
		if (field != null)
		    return field;
	    }

	    clazz = clazz.getSuperclass();
	}
	return null;
    }
    
    public FieldInfo getFieldInfo() {
	ClassInfo clazz;
	if (ref.getClazz().charAt(0) == '[')
	    clazz = classPath.getClassInfo("java.lang.Object");
	else
	    clazz = TypeSignature.getClassInfo(classPath, ref.getClazz());
        return getFieldInfo(clazz, ref.getName(), ref.getType());
    }

    public boolean needsCast(Type type) {
	if (type instanceof NullType)
	    return true;
	if (!(type instanceof ClassInfoType
	      && classType instanceof ClassInfoType))
	    return false;
	
	ClassInfo clazz = ((ClassInfoType) classType).getClassInfo();
	ClassInfo parClazz = ((ClassInfoType) type).getClassInfo();
	FieldInfo field = clazz.findField(ref.getName(), ref.getType());

	find_field:
	while (field == null) {
	    ClassInfo ifaces[] = clazz.getInterfaces();
	    for (int i = 0; i < ifaces.length; i++) {
		field = ifaces[i].findField(ref.getName(), ref.getType());
		if (field != null)
		    break find_field;
	    }
	    clazz = clazz.getSuperclass();
	    if (clazz == null)
		/* Weird, field not existing? */
		return false;
	    field = clazz.findField(ref.getName(), ref.getType());
	}	    
	if (Modifier.isPrivate(field.getModifiers()))
	    return parClazz != clazz;
	else if ((field.getModifiers() 
		  & (Modifier.PROTECTED | Modifier.PUBLIC)) == 0) {
	    /* Field is protected.  We need a cast if parClazz is in
	     * other package than clazz.
	     */
	    int lastDot = clazz.getName().lastIndexOf('.');
	    if (lastDot == -1
		|| lastDot != parClazz.getName().lastIndexOf('.')
		|| !(parClazz.getName()
		     .startsWith(clazz.getName().substring(0,lastDot))))
		return true;
	}
	    
	while (clazz != parClazz && clazz != null) {
	    FieldInfo[] fields = parClazz.getFields();
	    for (int i = 0; i < fields.length; i++) {
		if (fields[i].getName().equals(ref.getName()))
		    return true;
	    }
	    parClazz = parClazz.getSuperclass();
	}
	return false;
    }

    /**
     * We add the named method scoped classes to the declarables.
     */
    public void fillDeclarables(Collection used) {
	ClassInfo clazz = getClassInfo();
	ClassAnalyzer clazzAna = methodAnalyzer.getClassAnalyzer(clazz);

	if ((Options.options & Options.OPTION_ANON) != 0
	    && clazz != null
	    && clazz.isMethodScoped() && clazz.getClassName() != null
	    && clazzAna != null
	    && clazzAna.getParent() == methodAnalyzer) {

	    /* This is a named method scope class, declare it.
	     * But first declare all method scoped classes,
	     * that are used inside; order does matter.
	     */
	    clazzAna.fillDeclarables(used);
	    used.add(clazzAna);
	}
	super.fillDeclarables(used);
    }

    public void dumpExpression(TabbedPrintWriter writer)
	throws java.io.IOException {
	boolean opIsThis = !staticFlag
	    && subExpressions[0] instanceof ThisOperator;
	String fieldName = ref.getName();
	if (staticFlag) {
	    if (!classType.equals(Type.tClass(methodAnalyzer.getClazz()))
		|| methodAnalyzer.findLocal(fieldName) != null) {
		writer.printType(classType);
		writer.breakOp();
		writer.print(".");
	    }
	    writer.print(fieldName);
	} else if (needsCast(subExpressions[0].getType().getCanonic())) {
	    writer.print("(");
	    writer.startOp(TabbedPrintWriter.EXPL_PAREN, 1);
	    writer.print("(");
	    writer.printType(classType);
	    writer.print(") ");
	    writer.breakOp();
	    subExpressions[0].dumpExpression(writer, 700);
	    writer.endOp();
	    writer.print(")");
	    writer.breakOp();
	    writer.print(".");
	    writer.print(fieldName);
	} else {
	    if (opIsThis) {
		ThisOperator thisOp = (ThisOperator) subExpressions[0];
		Scope scope = writer.getScope(thisOp.getClassInfo(),
					      Scope.CLASSSCOPE);

		if (scope == null || writer.conflicts(fieldName, scope, 
						      Scope.FIELDNAME)) {
		    thisOp.dumpExpression(writer, 950);
		    writer.breakOp();
		    writer.print(".");
		} else if (writer.conflicts(fieldName, scope, 
					    Scope.AMBIGUOUSNAME)
			   || (/* This is a inherited field conflicting
				* with a field name in some outer class.
				*/
			       getField() == null 
			       && writer.conflicts(fieldName, null,
				 Scope.NOSUPERFIELDNAME))) {
		    thisOp.dumpExpression(writer, 950);
		    writer.breakOp();
		    writer.print(".");
		}
	    } else {
		subExpressions[0].dumpExpression(writer, 950);
		writer.breakOp();
		writer.print(".");
	    }
	    writer.print(fieldName);
	}
    }
}