/*
 * Copyright (c) 2005, 2015, 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
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package com.sun.tools.javac.code;

import java.lang.annotation.Annotation;
import java.lang.annotation.Inherited;
import java.lang.annotation.Repeatable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.lang.model.AnnotatedConstruct;

import com.sun.tools.javac.model.AnnotationProxyMaker;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.ListBuffer;

Common super type for annotated constructs such as Types and Symbols.
This class should *not* contain any fields since it would have a significant
impact on the javac memory footprint.
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.
/**
 * Common super type for annotated constructs such as Types and Symbols.
 *
 * This class should *not* contain any fields since it would have a significant
 * impact on the javac memory footprint.
 *
 * <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></p>
 */
public abstract class AnnoConstruct implements AnnotatedConstruct {


    // Override to enforce a narrower return type.
    @Override @DefinedBy(Api.LANGUAGE_MODEL)
    public abstract List<? extends Attribute.Compound> getAnnotationMirrors();


    // This method is part of the javax.lang.model API, do not use this in javac code.
    protected <A extends Annotation> Attribute.Compound getAttribute(Class<A> annoType) {
        String name = annoType.getName();

        for (Attribute.Compound anno : getAnnotationMirrors()) {
            if (name.equals(anno.type.tsym.flatName().toString()))
                return anno;
        }

        return null;
    }


    @SuppressWarnings("unchecked")
    protected <A extends Annotation> A[] getInheritedAnnotations(Class<A> annoType) {
        return (A[]) java.lang.reflect.Array.newInstance(annoType, 0);  // annoType is the Class for A
    }


    // This method is part of the javax.lang.model API, do not use this in javac code.
    @DefinedBy(Api.LANGUAGE_MODEL)
    public <A extends Annotation> A[] getAnnotationsByType(Class<A> annoType) {

        if (!annoType.isAnnotation())
            throw new IllegalArgumentException("Not an annotation type: "
                                               + annoType);
        // If annoType does not declare a container this is equivalent to wrapping
        // getAnnotation(...) in an array.
        Class <? extends Annotation> containerType = getContainer(annoType);
        if (containerType == null) {
            A res = getAnnotation(annoType);
            int size = res == null ? 0 : 1;

            @SuppressWarnings("unchecked") // annoType is the Class for A
            A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);
            if (res != null)
                arr[0] = res;
            return arr;
        }

        // So we have a containing type
        String annoTypeName = annoType.getName();
        String containerTypeName = containerType.getName();
        int directIndex = -1, containerIndex = -1;
        Attribute.Compound direct = null, container = null;
        // Find directly (explicit or implicit) present annotations
        int index = -1;
        for (Attribute.Compound attribute : getAnnotationMirrors()) {
            index++;
            if (attribute.type.tsym.flatName().contentEquals(annoTypeName)) {
                directIndex = index;
                direct = attribute;
            } else if(containerTypeName != null &&
                      attribute.type.tsym.flatName().contentEquals(containerTypeName)) {
                containerIndex = index;
                container = attribute;
            }
        }

        // Deal with inherited annotations
        if (direct == null && container == null &&
                annoType.isAnnotationPresent(Inherited.class))
            return getInheritedAnnotations(annoType);

        Attribute.Compound[] contained = unpackContained(container);

        // In case of an empty legacy container we might need to look for
        // inherited annos as well
        if (direct == null && contained.length == 0 &&
                annoType.isAnnotationPresent(Inherited.class))
            return getInheritedAnnotations(annoType);

        int size = (direct == null ? 0 : 1) + contained.length;
        @SuppressWarnings("unchecked") // annoType is the Class for A
        A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);

        // if direct && container, which is first?
        int insert = -1;
        int length = arr.length;
        if (directIndex >= 0 && containerIndex >= 0) {
            if (directIndex < containerIndex) {
                arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
                insert = 1;
            } else {
                arr[arr.length - 1] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
                insert = 0;
                length--;
            }
        } else if (directIndex >= 0) {
            arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
            return arr;
        } else {
            // Only container
            insert = 0;
        }

        for (int i = 0; i + insert < length; i++)
            arr[insert + i] = AnnotationProxyMaker.generateAnnotation(contained[i], annoType);

        return arr;
    }

    private Attribute.Compound[] unpackContained(Attribute.Compound container) {
        // Pack them in an array
        Attribute[] contained0 = null;
        if (container != null)
            contained0 = unpackAttributes(container);
        ListBuffer<Attribute.Compound> compounds = new ListBuffer<>();
        if (contained0 != null) {
            for (Attribute a : contained0)
                if (a instanceof Attribute.Compound)
                    compounds = compounds.append((Attribute.Compound)a);
        }
        return compounds.toArray(new Attribute.Compound[compounds.size()]);
    }

    // This method is part of the javax.lang.model API, do not use this in javac code.
    @DefinedBy(Api.LANGUAGE_MODEL)
    public <A extends Annotation> A getAnnotation(Class<A> annoType) {

        if (!annoType.isAnnotation())
            throw new IllegalArgumentException("Not an annotation type: " + annoType);

        Attribute.Compound c = getAttribute(annoType);
        return c == null ? null : AnnotationProxyMaker.generateAnnotation(c, annoType);
    }

    // Helper to getAnnotationsByType
    private static Class<? extends Annotation> getContainer(Class<? extends Annotation> annoType) {
        Repeatable repeatable = annoType.getAnnotation(Repeatable.class);
        return (repeatable == null) ? null : repeatable.value();
    }

    // Helper to getAnnotationsByType
    private static Attribute[] unpackAttributes(Attribute.Compound container) {
        // We now have an instance of the container,
        // unpack it returning an instance of the
        // contained type or null
        return ((Attribute.Array)container.member(container.type.tsym.name.table.names.value)).values;
    }

}