/*

 * Copyright (c) 2003, 2018, 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 jdk.javadoc.internal.doclets.toolkit.builders;

import java.util.*;

import javax.lang.model.element.Element;

import javax.lang.model.element.PackageElement;

import javax.lang.model.element.TypeElement;

import javax.lang.model.element.VariableElement;

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

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

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

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

import static jdk.javadoc.internal.doclets.toolkit.util.VisibleMemberTable.Kind.*;

/**

 * Builds the Constants Summary Page.

 *

 *  <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

 * @author Bhavesh Patel (Modified)

 */

public class ConstantsSummaryBuilder extends AbstractBuilder {

    /**

     * The maximum number of package directories shown in the constant

     * value index.

     */

    public static final int MAX_CONSTANT_VALUE_INDEX_LENGTH = 2;

    /**

     * The writer used to write the results.

     */

    protected final ConstantsSummaryWriter writer;

    /**

     * The set of TypeElements that have constant fields.

     */

    protected final Set<TypeElement> typeElementsWithConstFields;

    /**

     * The set of printed package headers.

     */

    protected final Set<PackageElement> printedPackageHeaders;

    /**

     * The current package being documented.

     */

    private PackageElement currentPackage;

    /**

     * The current class being documented.

     */

    private TypeElement currentClass;

    /**

     * True if first package is listed.

     */

    private boolean first = true;

    /**

     * Construct a new ConstantsSummaryBuilder.

     *

     * @param context       the build context.

     * @param writer        the writer for the summary.

     */

    private ConstantsSummaryBuilder(Context context,

            ConstantsSummaryWriter writer) {

        super(context);

        this.writer = writer;

        this.typeElementsWithConstFields = new HashSet<>();

        this.printedPackageHeaders = new TreeSet<>(utils.makePackageComparator());

    }

    /**

     * Construct a ConstantsSummaryBuilder.

     *

     * @param context       the build context.

     * @param writer        the writer for the summary.

     * @return the new ConstantsSummaryBuilder

     */

    public static ConstantsSummaryBuilder getInstance(Context context,

            ConstantsSummaryWriter writer) {

        return new ConstantsSummaryBuilder(context, writer);

    }

    /**

     * {@inheritDoc}

     * @throws DocletException if there is a problem while building the documentation

     */

    @Override

    public void build() throws DocletException {

        if (writer == null) {

            //Doclet does not support this output.

            return;

        }

    }

    /**

     * Build the constant summary.

     *

     * @throws DocletException if there is a problem while building the documentation

     */

        writer.printDocument(contentTree);

    }

    /**

     * Build the list of packages.

     */

        Content contentListTree = writer.getContentsHeader();

        printedPackageHeaders.clear();

        for (PackageElement pkg : configuration.packages) {

            if (hasConstantField(pkg) && !hasPrintedPackageIndex(pkg)) {

                writer.addLinkToPackageContent(pkg, printedPackageHeaders, contentListTree);

            }

        }

    }

    /**

     * Build the summary for each documented package.

     *

     * @throws DocletException if there is a problem while building the documentation

     */

        printedPackageHeaders.clear();

        Content summariesTree = writer.getConstantSummaries();

        for (PackageElement aPackage : configuration.packages) {

            if (hasConstantField(aPackage)) {

                currentPackage = aPackage;

                //Build the documentation for the current package.

                buildPackageHeader(summariesTree);

                buildClassConstantSummary(summariesTree);

                first = false;

            }

        }

    }

    /**

     * Build the header for the given package.

     *

     * @param summariesTree the tree to which the package header will be added

     */

    protected void buildPackageHeader(Content summariesTree) {

        PackageElement abbrevPkg = configuration.workArounds.getAbbreviatedPackageElement(currentPackage);

        if (!printedPackageHeaders.contains(abbrevPkg)) {

            writer.addPackageName(currentPackage, summariesTree, first);

            printedPackageHeaders.add(abbrevPkg);

        }

    }

    /**

     * Build the summary for the current class.

     *

     * @param summariesTree the tree to which the class constant summary will be added

     * @throws DocletException if there is a problem while building the documentation

     *

     */

    protected void buildClassConstantSummary(Content summariesTree)

            throws DocletException {

        SortedSet<TypeElement> classes = !currentPackage.isUnnamed()

                ? utils.getAllClasses(currentPackage)

                : configuration.typeElementCatalog.allUnnamedClasses();

        Content classConstantTree = writer.getClassConstantHeader();

        for (TypeElement te : classes) {

            if (!typeElementsWithConstFields.contains(te) ||

                !utils.isIncluded(te)) {

                continue;

            }

            currentClass = te;

            //Build the documentation for the current class.

            buildConstantMembers(classConstantTree);

        }

        writer.addClassConstant(summariesTree, classConstantTree);

    }

    /**

     * Build the summary of constant members in the class.

     *

     * @param classConstantTree the tree to which the constant members table

     *                          will be added

     */

    protected void buildConstantMembers(Content classConstantTree) {

        new ConstantFieldBuilder(currentClass).buildMembersSummary(classConstantTree);

    }

    /**

     * Return true if the given package has constant fields to document.

     *

     * @param pkg   the package being checked.

     * @return true if the given package has constant fields to document.

     */

    private boolean hasConstantField(PackageElement pkg) {

        SortedSet<TypeElement> classes = !pkg.isUnnamed()

                  ? utils.getAllClasses(pkg)

                  : configuration.typeElementCatalog.allUnnamedClasses();

        boolean found = false;

        for (TypeElement te : classes) {

            if (utils.isIncluded(te) && hasConstantField(te)) {

                found = true;

            }

        }

        return found;

    }

    /**

     * Return true if the given class has constant fields to document.

     *

     * @param typeElement the class being checked.

     * @return true if the given package has constant fields to document.

     */

    private boolean hasConstantField (TypeElement typeElement) {

        VisibleMemberTable vmt = configuration.getVisibleMemberTable(typeElement);

        List<? extends Element> fields = vmt.getVisibleMembers(FIELDS);

        for (Element f : fields) {

            VariableElement field = (VariableElement)f;

            if (field.getConstantValue() != null) {

                typeElementsWithConstFields.add(typeElement);

                return true;

            }

        }

        return false;

    }

    /**

     * Return true if the given package name has been printed.  Also

     * return true if the root of this package has been printed.

     *

     * @param pkg the name of the package to check.

     */

    private boolean hasPrintedPackageIndex(PackageElement pkg) {

        for (PackageElement printedPkg : printedPackageHeaders) {

            if (utils.getPackageName(pkg).startsWith(utils.parsePackageName(printedPkg))) {

                return true;

            }

        }

        return false;

    }

    /**

     * Print the table of constants.

     *

     * @author Jamie Ho

     */

    private class ConstantFieldBuilder {

        /**

         * The typeElement that we are examining constants for.

         */

        protected TypeElement typeElement;

        /**

         * Construct a ConstantFieldSubWriter.

         * @param typeElement the typeElement that we are examining constants for.

         */

        public ConstantFieldBuilder(TypeElement typeElement) {

            this.typeElement = typeElement;

        }

        /**

         * Builds the table of constants for a given class.

         *

         * @param classConstantTree the tree to which the class constants table

         *                          will be added

         */

        protected void buildMembersSummary(Content classConstantTree) {

            SortedSet<VariableElement> members = members();

            if (!members.isEmpty()) {

                writer.addConstantMembers(typeElement, members, classConstantTree);

            }

        }

        /**

         * Returns a set of visible constant fields for the given type.

         * @return the set of visible constant fields for the given type.

         */

        protected SortedSet<VariableElement> members() {

            VisibleMemberTable vmt = configuration.getVisibleMemberTable(typeElement);

            List<Element> members = new ArrayList<>();

            members.addAll(vmt.getVisibleMembers(FIELDS));

            members.addAll(vmt.getVisibleMembers(ENUM_CONSTANTS));

            SortedSet<VariableElement> includes =

                    new TreeSet<>(utils.makeGeneralPurposeComparator());

            for (Element element : members) {

                VariableElement member = (VariableElement)element;

                if (member.getConstantValue() != null) {

                    includes.add(member);

                }

            }

            return includes;

        }

    }

}