/*

 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javac.comp;

import com.sun.tools.javac.util.*;

import com.sun.tools.javac.code.*;

import com.sun.tools.javac.code.Symbol.*;

import com.sun.tools.javac.tree.*;

import com.sun.tools.javac.tree.JCTree.*;

/** Enter annotations on symbols.  Annotations accumulate in a queue,

 *  which is processed at the top level of any set of recursive calls

 *  requesting it be processed.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class Annotate {

    protected static final Context.Key<Annotate> annotateKey =

        new Context.Key<Annotate>();

    public static Annotate instance(Context context) {

        Annotate instance = context.get(annotateKey);

        if (instance == null)

            instance = new Annotate(context);

        return instance;

    }

    final Attr attr;

    final TreeMaker make;

    final Log log;

    final Symtab syms;

    final Names names;

    final Resolve rs;

    final Types types;

    final ConstFold cfolder;

    final Check chk;

    protected Annotate(Context context) {

        context.put(annotateKey, this);

        attr = Attr.instance(context);

        make = TreeMaker.instance(context);

        log = Log.instance(context);

        syms = Symtab.instance(context);

        names = Names.instance(context);

        rs = Resolve.instance(context);

        types = Types.instance(context);

        cfolder = ConstFold.instance(context);

        chk = Check.instance(context);

    }

/* ********************************************************************

 * Queue maintenance

 *********************************************************************/

    private int enterCount = 0;

    ListBuffer<Annotator> q = new ListBuffer<Annotator>();

    public void later(Annotator a) {

        q.append(a);

    }

    public void earlier(Annotator a) {

        q.prepend(a);

    }

    /** Called when the Enter phase starts. */

    public void enterStart() {

        enterCount++;

    }

    /** Called after the Enter phase completes. */

    public void enterDone() {

        enterCount--;

        flush();

    }

    public void flush() {

        if (enterCount != 0) return;

        enterCount++;

        try {

            while (q.nonEmpty())

                q.next().enterAnnotation();

        } finally {

            enterCount--;

        }

    }

    /** A client that has annotations to add registers an annotator,

     *  the method it will use to add the annotation.  There are no

     *  parameters; any needed data should be captured by the

     *  Annotator.

     */

    public interface Annotator {

        void enterAnnotation();

        String toString();

    }

/* ********************************************************************

 * Compute an attribute from its annotation.

 *********************************************************************/

    /** Process a single compound annotation, returning its

     *  Attribute. Used from MemberEnter for attaching the attributes

     *  to the annotated symbol.

     */

    Attribute.Compound enterAnnotation(JCAnnotation a,

                                       Type expected,

                                       Env<AttrContext> env) {

        // The annotation might have had its type attributed (but not checked)

        // by attr.attribAnnotationTypes during MemberEnter, in which case we do not

        // need to do it again.

        Type at = (a.annotationType.type != null ? a.annotationType.type

                  : attr.attribType(a.annotationType, env));

        a.type = chk.checkType(a.annotationType.pos(), at, expected);

        if (a.type.isErroneous())

            return new Attribute.Compound(a.type, List.<Pair<MethodSymbol,Attribute>>nil());

        if ((a.type.tsym.flags() & Flags.ANNOTATION) == 0) {

            log.error(a.annotationType.pos(),

                      "not.annotation.type", a.type.toString());

            return new Attribute.Compound(a.type, List.<Pair<MethodSymbol,Attribute>>nil());

        }

        List<JCExpression> args = a.args;

        if (args.length() == 1 && args.head.getTag() != JCTree.ASSIGN) {

            // special case: elided "value=" assumed

            args.head = make.at(args.head.pos).

                Assign(make.Ident(names.value), args.head);

        }

        ListBuffer<Pair<MethodSymbol,Attribute>> buf =

            new ListBuffer<Pair<MethodSymbol,Attribute>>();

        for (List<JCExpression> tl = args; tl.nonEmpty(); tl = tl.tail) {

            JCExpression t = tl.head;

            if (t.getTag() != JCTree.ASSIGN) {

                log.error(t.pos(), "annotation.value.must.be.name.value");

                continue;

            }

            JCAssign assign = (JCAssign)t;

            if (assign.lhs.getTag() != JCTree.IDENT) {

                log.error(t.pos(), "annotation.value.must.be.name.value");

                continue;

            }

            JCIdent left = (JCIdent)assign.lhs;

            Symbol method = rs.resolveQualifiedMethod(left.pos(),

            left.sym = method;

            left.type = method.type;

            if (method.owner != a.type.tsym)

                log.error(left.pos(), "no.annotation.member", left.name, a.type);

            Type result = method.type.getReturnType();

            Attribute value = enterAttributeValue(result, assign.rhs, env);

            if (!method.type.isErroneous())

                buf.append(new Pair<MethodSymbol,Attribute>

                           ((MethodSymbol)method, value));

            t.type = result;

        }

        return new Attribute.Compound(a.type, buf.toList());

    }

    Attribute enterAttributeValue(Type expected,

                                  JCExpression tree,

                                  Env<AttrContext> env) {

        if (expected.isPrimitive() || types.isSameType(expected, syms.stringType)) {

            Type result = attr.attribExpr(tree, env, expected);

            if (result.isErroneous())

                return new Attribute.Error(expected);

            if (result.constValue() == null) {

                log.error(tree.pos(), "attribute.value.must.be.constant");

                return new Attribute.Error(expected);

            }

            result = cfolder.coerce(result, expected);

            return new Attribute.Constant(expected, result.constValue());

        }

        if (expected.tsym == syms.classType.tsym) {

            Type result = attr.attribExpr(tree, env, expected);

            if (result.isErroneous())

                return new Attribute.Error(expected);

            if (TreeInfo.name(tree) != names._class) {

                log.error(tree.pos(), "annotation.value.must.be.class.literal");

                return new Attribute.Error(expected);

            }

            return new Attribute.Class(types,

                                       (((JCFieldAccess) tree).selected).type);

        }

        if ((expected.tsym.flags() & Flags.ANNOTATION) != 0) {

            if (tree.getTag() != JCTree.ANNOTATION) {

                log.error(tree.pos(), "annotation.value.must.be.annotation");

                expected = syms.errorType;

            }

            return enterAnnotation((JCAnnotation)tree, expected, env);

        }

        if (expected.tag == TypeTags.ARRAY) { // should really be isArray()

            if (tree.getTag() != JCTree.NEWARRAY) {

                tree = make.at(tree.pos).

                    NewArray(null, List.<JCExpression>nil(), List.of(tree));

            }

            JCNewArray na = (JCNewArray)tree;

            if (na.elemtype != null) {

                log.error(na.elemtype.pos(), "new.not.allowed.in.annotation");

                return new Attribute.Error(expected);

            }

            ListBuffer<Attribute> buf = new ListBuffer<Attribute>();

            for (List<JCExpression> l = na.elems; l.nonEmpty(); l=l.tail) {

                buf.append(enterAttributeValue(types.elemtype(expected),

                                               l.head,

                                               env));

            }

            na.type = expected;

            return new Attribute.

                Array(expected, buf.toArray(new Attribute[buf.length()]));

        }

        if (expected.tag == TypeTags.CLASS &&

            (expected.tsym.flags() & Flags.ENUM) != 0) {

            attr.attribExpr(tree, env, expected);

            Symbol sym = TreeInfo.symbol(tree);

            if (sym == null ||

                TreeInfo.nonstaticSelect(tree) ||

                sym.kind != Kinds.VAR ||

                (sym.flags() & Flags.ENUM) == 0) {

                log.error(tree.pos(), "enum.annotation.must.be.enum.constant");

                return new Attribute.Error(expected);

            }

            VarSymbol enumerator = (VarSymbol) sym;

            return new Attribute.Enum(expected, enumerator);

        }

        if (!expected.isErroneous())

            log.error(tree.pos(), "annotation.value.not.allowable.type");

        return new Attribute.Error(attr.attribExpr(tree, env, expected));

    }

}