/*

 * Copyright (c) 2003, 2013, 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.code;

import java.util.LinkedHashMap;

import java.util.Map;

import javax.lang.model.element.AnnotationMirror;

import javax.lang.model.element.AnnotationValue;

import javax.lang.model.element.AnnotationValueVisitor;

import javax.lang.model.type.DeclaredType;

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

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

/** An annotation value.

 *

 *  <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 abstract class Attribute implements AnnotationValue {

    /** The type of the annotation element. */

    public Type type;

    public Attribute(Type type) {

        this.type = type;

    }

    public abstract void accept(Visitor v);

    public Object getValue() {

        throw new UnsupportedOperationException();

    }

    public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

        throw new UnsupportedOperationException();

    }

    public boolean isSynthesized() {

        return false;

    }

    public TypeAnnotationPosition getPosition() { return null; }

    /** The value for an annotation element of primitive type or String. */

    public static class Constant extends Attribute {

        public final Object value;

        public void accept(Visitor v) { v.visitConstant(this); }

        public Constant(Type type, Object value) {

            super(type);

            this.value = value;

        }

        public String toString() {

            return Constants.format(value, type);

        }

        public Object getValue() {

            return Constants.decode(value, type);

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            if (value instanceof String)

                return v.visitString((String) value, p);

            if (value instanceof Integer) {

                int i = (Integer) value;

                switch (type.getTag()) {

                case BOOLEAN:   return v.visitBoolean(i != 0, p);

                case CHAR:      return v.visitChar((char) i, p);

                case BYTE:      return v.visitByte((byte) i, p);

                case SHORT:     return v.visitShort((short) i, p);

                case INT:       return v.visitInt(i, p);

                }

            }

            switch (type.getTag()) {

            case LONG:          return v.visitLong((Long) value, p);

            case FLOAT:         return v.visitFloat((Float) value, p);

            case DOUBLE:        return v.visitDouble((Double) value, p);

            }

            throw new AssertionError("Bad annotation element value: " + value);

        }

    }

    /** The value for an annotation element of type java.lang.Class,

     *  represented as a ClassSymbol.

     */

    public static class Class extends Attribute {

        public final Type classType;

        public void accept(Visitor v) { v.visitClass(this); }

        public Class(Types types, Type type) {

            super(makeClassType(types, type));

            this.classType = type;

        }

        static Type makeClassType(Types types, Type type) {

            Type arg = type.isPrimitive()

                ? types.boxedClass(type).type

                : types.erasure(type);

            return new Type.ClassType(types.syms.classType.getEnclosingType(),

                                      List.of(arg),

                                      types.syms.classType.tsym,

                                      Type.noAnnotations);

        }

        public String toString() {

            return classType + ".class";

        }

        public Type getValue() {

            return classType;

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            return v.visitType(classType, p);

        }

    }

    /** A compound annotation element value, the type of which is an

     *  attribute interface.

     */

    public static class Compound extends Attribute implements AnnotationMirror {

        /** The attributes values, as pairs.  Each pair contains a

         *  reference to the accessing method in the attribute interface

         *  and the value to be returned when that method is called to

         *  access this attribute.

         */

        public final List<Pair<MethodSymbol,Attribute>> values;

        public final TypeAnnotationPosition position;

        private boolean synthesized = false;

        @Override

        public boolean isSynthesized() {

            return synthesized;

        }

        public void setSynthesized(boolean synthesized) {

            this.synthesized = synthesized;

        }

        public Compound(Type type,

                        List<Pair<MethodSymbol,Attribute>> values,

                        TypeAnnotationPosition position) {

            super(type);

            this.values = values;

            this.position = position;

        }

        public Compound(Type type,

                        List<Pair<MethodSymbol,Attribute>> values) {

            this(type, values, null);

        }

        @Override

        public TypeAnnotationPosition getPosition() {

            return position;

        }

        public void accept(Visitor v) { v.visitCompound(this); }

        /**

         * Returns a string representation of this annotation.

         * String is of one of the forms:

         *     @com.example.foo(name1=val1, name2=val2)

         *     @com.example.foo(val)

         *     @com.example.foo

         * Omit parens for marker annotations, and omit "value=" when allowed.

         */

        public String toString() {

            StringBuilder buf = new StringBuilder();

            buf.append("@");

            buf.append(type);

            int len = values.length();

            if (len > 0) {

                buf.append('(');

                boolean first = true;

                for (Pair<MethodSymbol, Attribute> value : values) {

                    if (!first) buf.append(", ");

                    first = false;

                    Name name = value.fst.name;

                    if (len > 1 || name != name.table.names.value) {

                        buf.append(name);

                        buf.append('=');

                    }

                    buf.append(value.snd);

                }

                buf.append(')');

            }

            return buf.toString();

        }

        public Attribute member(Name member) {

            Pair<MethodSymbol,Attribute> res = getElemPair(member);

            return res == null ? null : res.snd;

        }

        private Pair<MethodSymbol, Attribute> getElemPair(Name member) {

            for (Pair<MethodSymbol,Attribute> pair : values)

                if (pair.fst.name == member) return pair;

            return null;

        }

        public Attribute.Compound getValue() {

            return this;

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            return v.visitAnnotation(this, p);

        }

        public DeclaredType getAnnotationType() {

            return (DeclaredType) type;

        }

        public Map<MethodSymbol, Attribute> getElementValues() {

            Map<MethodSymbol, Attribute> valmap = new LinkedHashMap<>();

            for (Pair<MethodSymbol, Attribute> value : values)

                valmap.put(value.fst, value.snd);

            return valmap;

        }

        public TypeCompound toTypeCompound() {

            // It is safe to alias the position.

            return new TypeCompound(this, this.position);

        }

    }

    public static class TypeCompound extends Compound {

        public TypeCompound(Compound compound,

                             TypeAnnotationPosition position) {

            super(compound.type, compound.values, position);

        }

        public TypeCompound(Type type,

                             List<Pair<MethodSymbol,Attribute>> values,

                             TypeAnnotationPosition position) {

            super(type, values, position);

        }

    }

    /** The value for an annotation element of an array type.

     */

    public static class Array extends Attribute {

        public final Attribute[] values;

        public Array(Type type, Attribute[] values) {

            super(type);

            this.values = values;

        }

        public Array(Type type, List<Attribute> values) {

            super(type);

            this.values = values.toArray(new Attribute[values.size()]);

        }

        public void accept(Visitor v) { v.visitArray(this); }

        public String toString() {

            StringBuilder buf = new StringBuilder();

            buf.append('{');

            boolean first = true;

            for (Attribute value : values) {

                if (!first)

                    buf.append(", ");

                first = false;

                buf.append(value);

            }

            buf.append('}');

            return buf.toString();

        }

        public List<Attribute> getValue() {

            return List.from(values);

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            return v.visitArray(getValue(), p);

        }

        @Override

        public TypeAnnotationPosition getPosition() {

            if (values.length != 0)

                return values[0].getPosition();

            else

                return null;

        }

    }

    /** The value for an annotation element of an enum type.

     */

    public static class Enum extends Attribute {

        public VarSymbol value;

        public Enum(Type type, VarSymbol value) {

            super(type);

            this.value = Assert.checkNonNull(value);

        }

        public void accept(Visitor v) { v.visitEnum(this); }

        public String toString() {

            return value.enclClass() + "." + value;     // qualified name

        }

        public VarSymbol getValue() {

            return value;

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            return v.visitEnumConstant(value, p);

        }

    }

    public static class Error extends Attribute {

        public Error(Type type) {

            super(type);

        }

        public void accept(Visitor v) { v.visitError(this); }

        public String toString() {

            return "<error>";

        }

        public String getValue() {

            return toString();

        }

        public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {

            return v.visitString(toString(), p);

        }

    }

    public static class UnresolvedClass extends Error {

        public Type classType;

        public UnresolvedClass(Type type, Type classType) {

            super(type);

            this.classType = classType;

        }

    }

    /** A visitor type for dynamic dispatch on the kind of attribute value. */

    public static interface Visitor {

        void visitConstant(Attribute.Constant value);

        void visitClass(Attribute.Class clazz);

        void visitCompound(Attribute.Compound compound);

        void visitArray(Attribute.Array array);

        void visitEnum(Attribute.Enum e);

        void visitError(Attribute.Error e);

    }

    /** A mirror of java.lang.annotation.RetentionPolicy. */

    public static enum RetentionPolicy {

        SOURCE,

        CLASS,

        RUNTIME

    }

}