/*

 * Copyright (c) 2003, 2016, 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 jdk.javadoc.internal.doclets.toolkit.util.links;

import java.util.ArrayList;

import java.util.List;

import javax.lang.model.element.AnnotationMirror;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.lang.model.element.TypeParameterElement;

import javax.lang.model.type.ArrayType;

import javax.lang.model.type.DeclaredType;

import javax.lang.model.type.TypeMirror;

import javax.lang.model.type.TypeVariable;

import javax.lang.model.type.WildcardType;

import javax.lang.model.util.SimpleTypeVisitor9;

import jdk.javadoc.internal.doclets.formats.html.LinkInfoImpl;

import jdk.javadoc.internal.doclets.toolkit.Content;

import jdk.javadoc.internal.doclets.toolkit.util.Utils;

/**

 * A factory that constructs links from given link information.

 *

 *  <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>

 *

 * @author Jamie Ho

 */

public abstract class LinkFactory {

    /**

     * Return an empty instance of a content object.

     *

     * @return an empty instance of a content object.

     */

    protected abstract Content newContent();

    /**

     * Constructs a link from the given link information.

     *

     * @param linkInfo the information about the link.

     * @return the output of the link.

     */

    public Content getLink(LinkInfo linkInfo) {

        Utils utils = ((LinkInfoImpl) linkInfo).configuration.utils;

        if (linkInfo.type != null) {

            SimpleTypeVisitor9<Content, LinkInfo> linkVisitor =

                    new SimpleTypeVisitor9<Content, LinkInfo>() {

                TypeMirror componentType = utils.getComponentType(linkInfo.type);

                Content link = newContent();

                // handles primitives, no types and error types

                @Override

                protected Content defaultAction(TypeMirror type, LinkInfo linkInfo) {

                    link.addContent(utils.getTypeName(type, false));

                    return link;

                }

                int currentDepth = 0;

                @Override

                public Content visitArray(ArrayType type, LinkInfo linkInfo) {

                    // keep track of the dimension depth and replace the last dimension

                    // specifier with vararags, when the stack is fully unwound.

                    currentDepth++;

                    linkInfo.type = type.getComponentType();

                    visit(linkInfo.type, linkInfo);

                    currentDepth--;

                    if (utils.isAnnotated(type)) {

                        linkInfo.type = type;

                        link.addContent(" ");

                        link.addContent(getTypeAnnotationLinks(linkInfo));

                    }

                    // use vararg if required

                    if (linkInfo.isVarArg && currentDepth == 0) {

                        link.addContent("...");

                    } else {

                        link.addContent("[]");

                    }

                    return link;

                }

                @Override

                public Content visitWildcard(WildcardType type, LinkInfo linkInfo) {

                    linkInfo.isTypeBound = true;

                    link.addContent("?");

                    TypeMirror extendsBound = type.getExtendsBound();

                    if (extendsBound != null) {

                        link.addContent(" extends ");

                        setBoundsLinkInfo(linkInfo, extendsBound);

                        link.addContent(getLink(linkInfo));

                    }

                    TypeMirror superBound = type.getSuperBound();

                    if (superBound != null) {

                        link.addContent(" super ");

                        setBoundsLinkInfo(linkInfo, superBound);

                        link.addContent(getLink(linkInfo));

                    }

                    return link;

                }

                @Override

                public Content visitTypeVariable(TypeVariable type, LinkInfo linkInfo) {

                    link.addContent(getTypeAnnotationLinks(linkInfo));

                    linkInfo.isTypeBound = true;

                    TypeVariable typevariable = (utils.isArrayType(type))

                            ? (TypeVariable) componentType

                            : type;

                    Element owner = typevariable.asElement().getEnclosingElement();

                    if ((!linkInfo.excludeTypeParameterLinks) && utils.isTypeElement(owner)) {

                        linkInfo.typeElement = (TypeElement) owner;

                        Content label = newContent();

                        label.addContent(utils.getTypeName(type, false));

                        linkInfo.label = label;

                        link.addContent(getClassLink(linkInfo));

                    } else {

                        // No need to link method type parameters.

                        link.addContent(utils.getTypeName(typevariable, false));

                    }

                    if (!linkInfo.excludeTypeBounds) {

                        linkInfo.excludeTypeBounds = true;

                        TypeParameterElement tpe = ((TypeParameterElement) typevariable.asElement());

                        boolean more = false;

                        List<? extends TypeMirror> bounds = utils.getBounds(tpe);

                        for (TypeMirror bound : bounds) {

                            // we get everything as extends java.lang.Object we suppress

                            // all of them except those that have multiple extends

                            if (bounds.size() == 1 &&

                                    bound.equals(utils.getObjectType()) &&

                                    !utils.isAnnotated(bound)) {

                                continue;

                            }

                            link.addContent(more ? " & " : " extends ");

                            setBoundsLinkInfo(linkInfo, bound);

                            link.addContent(getLink(linkInfo));

                            more = true;

                        }

                    }

                    return link;

                }

                @Override

                public Content visitDeclared(DeclaredType type, LinkInfo linkInfo) {

                    if (linkInfo.isTypeBound && linkInfo.excludeTypeBoundsLinks) {

                        // Since we are excluding type parameter links, we should not

                        // be linking to the type bound.

                        link.addContent(utils.getTypeName(type, false));

                        link.addContent(getTypeParameterLinks(linkInfo));

                        return link;

                    } else {

                        link = newContent();

                        link.addContent(getTypeAnnotationLinks(linkInfo));

                        linkInfo.typeElement = utils.asTypeElement(type);

                        link.addContent(getClassLink(linkInfo));

                        if (linkInfo.includeTypeAsSepLink) {

                            link.addContent(getTypeParameterLinks(linkInfo, false));

                        }

                    }

                    return link;

                }

            };

            return linkVisitor.visit(linkInfo.type, linkInfo);

        } else if (linkInfo.typeElement != null) {

            Content link = newContent();

            link.addContent(getClassLink(linkInfo));

            if (linkInfo.includeTypeAsSepLink) {

                link.addContent(getTypeParameterLinks(linkInfo, false));

            }

            return link;

        } else {

            return null;

        }

    }

    private void setBoundsLinkInfo(LinkInfo linkInfo, TypeMirror bound) {

        linkInfo.typeElement = null;

        linkInfo.label = null;

        linkInfo.type = bound;

    }

    /**

     * Return the link to the given class.

     *

     * @param linkInfo the information about the link to construct.

     *

     * @return the link for the given class.

     */

    protected abstract Content getClassLink(LinkInfo linkInfo);

    /**

     * Return the link to the given type parameter.

     *

     * @param linkInfo     the information about the link to construct.

     * @param typeParam the type parameter to link to.

     */

    protected abstract Content getTypeParameterLink(LinkInfo linkInfo, TypeMirror typeParam);

    protected abstract Content getTypeAnnotationLink(LinkInfo linkInfo, AnnotationMirror annotation);

    /**

     * Return the links to the type parameters.

     *

     * @param linkInfo     the information about the link to construct.

     * @return the links to the type parameters.

     */

    public Content getTypeParameterLinks(LinkInfo linkInfo) {

        return getTypeParameterLinks(linkInfo, true);

    }

    /**

     * Return the links to the type parameters.

     *

     * @param linkInfo     the information about the link to construct.

     * @param isClassLabel true if this is a class label.  False if it is

     *                     the type parameters portion of the link.

     * @return the links to the type parameters.

     */

    public Content getTypeParameterLinks(LinkInfo linkInfo, boolean isClassLabel) {

        Utils utils = ((LinkInfoImpl)linkInfo).utils;

        Content links = newContent();

        List<TypeMirror> vars = new ArrayList<>();

        TypeMirror ctype = linkInfo.type != null

                ? utils.getComponentType(linkInfo.type)

                : null;

        if (linkInfo.executableElement != null) {

            linkInfo.executableElement.getTypeParameters().stream().forEach((t) -> {

                vars.add(t.asType());

            });

        } else if (linkInfo.type != null && utils.isDeclaredType(linkInfo.type)) {

        } else if (ctype != null && utils.isDeclaredType(ctype)) {

        } else if (linkInfo.typeElement != null) {

            linkInfo.typeElement.getTypeParameters().stream().forEach((t) -> {

                vars.add(t.asType());

            });

        } else {

            // Nothing to document.

            return links;

        }

        if (((linkInfo.includeTypeInClassLinkLabel && isClassLabel)

                || (linkInfo.includeTypeAsSepLink && !isClassLabel)) && !vars.isEmpty()) {

            links.addContent("<");

            boolean many = false;

            for (TypeMirror t : vars) {

                if (many) {

                    links.addContent(",");

                }

                links.addContent(getTypeParameterLink(linkInfo, t));

                many = true;

            }

            links.addContent(">");

        }

        return links;

    }

    public Content getTypeAnnotationLinks(LinkInfo linkInfo) {

        Utils utils = ((LinkInfoImpl)linkInfo).utils;

        Content links = newContent();

        if (!utils.isAnnotated(linkInfo.type))

            return links;

        List<? extends AnnotationMirror> annotations = linkInfo.type.getAnnotationMirrors();

        boolean needSpace = false;

        for (AnnotationMirror anno : annotations) {

            if (needSpace) {

                links.addContent(" ");

            }

            links.addContent(getTypeAnnotationLink(linkInfo, anno));

            needSpace = true;

        }

        links.addContent(" ");

        return links;

    }

}