/*
 * Copyright 2004-2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.apt.mirror.util;


import java.util.Collection;

import com.sun.mirror.declaration.*;
import com.sun.mirror.type.*;
import com.sun.mirror.util.Types;
import com.sun.tools.apt.mirror.AptEnv;
import com.sun.tools.apt.mirror.declaration.*;
import com.sun.tools.apt.mirror.type.TypeMirrorImpl;
import com.sun.tools.javac.code.BoundKind;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Symbol.ClassSymbol;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.ListBuffer;


/**
 * Implementation of Types utility methods for annotation processors
 */
@SuppressWarnings("deprecation")
public class TypesImpl implements Types {

    private final AptEnv env;


    private static final Context.Key<Types> typesKey =
            new Context.Key<Types>();

    public static Types instance(Context context) {
        Types instance = context.get(typesKey);
        if (instance == null) {
            instance = new TypesImpl(context);
        }
        return instance;
    }

    private TypesImpl(Context context) {
        context.put(typesKey, this);
        env = AptEnv.instance(context);
    }


    /**
     * {@inheritDoc}
     */
    public boolean isSubtype(TypeMirror t1, TypeMirror t2) {
        return env.jctypes.isSubtype(((TypeMirrorImpl) t1).type,
                                     ((TypeMirrorImpl) t2).type);
    }

    /**
     * {@inheritDoc}
     */
    public boolean isAssignable(TypeMirror t1, TypeMirror t2) {
        return env.jctypes.isAssignable(((TypeMirrorImpl) t1).type,
                                        ((TypeMirrorImpl) t2).type);
    }

    /**
     * {@inheritDoc}
     */
    public TypeMirror getErasure(TypeMirror t) {
        return env.typeMaker.getType(
                env.jctypes.erasure(((TypeMirrorImpl) t).type));
    }

    /**
     * {@inheritDoc}
     */
    public PrimitiveType getPrimitiveType(PrimitiveType.Kind kind) {
        Type prim = null;
        switch (kind) {
        case BOOLEAN:   prim = env.symtab.booleanType;  break;
        case BYTE:      prim = env.symtab.byteType;     break;
        case SHORT:     prim = env.symtab.shortType;    break;
        case INT:       prim = env.symtab.intType;      break;
        case LONG:      prim = env.symtab.longType;     break;
        case CHAR:      prim = env.symtab.charType;     break;
        case FLOAT:     prim = env.symtab.floatType;    break;
        case DOUBLE:    prim = env.symtab.doubleType;   break;
        default:        assert false;
        }
        return (PrimitiveType) env.typeMaker.getType(prim);
    }

    /**
     * {@inheritDoc}
     */
    public VoidType getVoidType() {
        return (VoidType) env.typeMaker.getType(env.symtab.voidType);
    }

    /**
     * {@inheritDoc}
     */
    public ArrayType getArrayType(TypeMirror componentType) {
        if (componentType instanceof VoidType) {
            throw new IllegalArgumentException("void");
        }
        return (ArrayType) env.typeMaker.getType(
                new Type.ArrayType(((TypeMirrorImpl) componentType).type,
                                   env.symtab.arrayClass));
    }

    /**
     * {@inheritDoc}
     */
    public TypeVariable getTypeVariable(TypeParameterDeclaration tparam) {
        return (TypeVariable) env.typeMaker.getType(
                                ((DeclarationImpl) tparam).sym.type);
    }

    /**
     * {@inheritDoc}
     */
    public WildcardType getWildcardType(Collection<ReferenceType> upperBounds,
                                        Collection<ReferenceType> lowerBounds) {
        BoundKind kind;
        Type bound;
        int uppers  = upperBounds.size();
        int downers = lowerBounds.size();

        if (uppers + downers > 1) {
            throw new IllegalArgumentException("Multiple bounds not allowed");

        } else if (uppers + downers == 0) {
            kind = BoundKind.UNBOUND;
            bound = env.symtab.objectType;

        } else if (uppers == 1) {
            assert downers == 0;
            kind = BoundKind.EXTENDS;
            bound = ((TypeMirrorImpl) upperBounds.iterator().next()).type;

        } else {
            assert uppers == 0 && downers == 1;
            kind = BoundKind.SUPER;
            bound = ((TypeMirrorImpl) lowerBounds.iterator().next()).type;
        }

        if (bound instanceof Type.WildcardType)
            throw new IllegalArgumentException(bound.toString());

        return (WildcardType) env.typeMaker.getType(
                new Type.WildcardType(bound, kind, env.symtab.boundClass));
    }

    /**
     * {@inheritDoc}
     */
    public DeclaredType getDeclaredType(TypeDeclaration decl,
                                        TypeMirror... typeArgs) {
        ClassSymbol sym = ((TypeDeclarationImpl) decl).sym;

        if (typeArgs.length == 0)
            return (DeclaredType) env.typeMaker.getType(
                                        env.jctypes.erasure(sym.type));
        if (sym.type.getEnclosingType().isParameterized())
            throw new IllegalArgumentException(decl.toString());

        return getDeclaredType(sym.type.getEnclosingType(), sym, typeArgs);
    }

    /**
     * {@inheritDoc}
     */
    public DeclaredType getDeclaredType(DeclaredType containing,
                                        TypeDeclaration decl,
                                        TypeMirror... typeArgs) {
        if (containing == null)
            return getDeclaredType(decl, typeArgs);

        ClassSymbol sym = ((TypeDeclarationImpl) decl).sym;
        Type outer = ((TypeMirrorImpl) containing).type;

        if (outer.tsym != sym.owner.enclClass())
            throw new IllegalArgumentException(containing.toString());
        if (!outer.isParameterized())
            return getDeclaredType(decl, typeArgs);

        return getDeclaredType(outer, sym, typeArgs);
    }

    private DeclaredType getDeclaredType(Type outer,
                                         ClassSymbol sym,
                                         TypeMirror... typeArgs) {
        if (typeArgs.length != sym.type.getTypeArguments().length())
            throw new IllegalArgumentException(
                                "Incorrect number of type arguments");

        ListBuffer<Type> targs = new ListBuffer<Type>();
        for (TypeMirror t : typeArgs) {
            if (!(t instanceof ReferenceType || t instanceof WildcardType))
                throw new IllegalArgumentException(t.toString());
            targs.append(((TypeMirrorImpl) t).type);
        }
        //### Need a way to check that type args match formals.

        return (DeclaredType) env.typeMaker.getType(
                new Type.ClassType(outer, targs.toList(), sym));
    }
}