/*

 * 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.util;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.SortedSet;

import java.util.TreeSet;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.lang.model.type.TypeMirror;

import jdk.javadoc.doclet.DocletEnvironment;

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

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

/**

 * Build Class Hierarchy for all the Classes. This class builds the Class

 * Tree and the Interface Tree separately.

 *

 *  <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>

 *

 * @see java.util.HashMap

 * @see java.util.List

 * @author Atul M Dambalkar

 */

public class ClassTree {

    /**

     * List of base classes. Used to get the mapped listing of sub-classes.

     */

    private final SortedSet<TypeElement> baseClasses;

    /**

     * Mapping for each Class with their sub classes

     */

    private final Map<TypeElement, SortedSet<TypeElement>> subClasses = new HashMap<>();

    /**

     * List of base-interfaces. Contains set of all the interfaces who do not

     * have super-interfaces. Can be used to get the mapped listing of

     * sub-interfaces.

     */

    private final SortedSet<TypeElement> baseInterfaces;

   /**

    * Mapping for each Interface with their SubInterfaces

    */

    private final Map<TypeElement, SortedSet<TypeElement>> subInterfaces = new HashMap<>();

    private final SortedSet<TypeElement> baseEnums;

    private final Map<TypeElement, SortedSet<TypeElement>> subEnums = new HashMap<>();

    private final SortedSet<TypeElement> baseAnnotationTypes;

    private final Map<TypeElement, SortedSet<TypeElement>> subAnnotationTypes = new HashMap<>();

   /**

    * Mapping for each Interface with classes who implement it.

    */

    private final Map<TypeElement, SortedSet<TypeElement>> implementingClasses = new HashMap<>();

    private final BaseConfiguration configuration;

    private final Utils utils;

    private final Comparator<Element> comparator;

    /**

     * Constructor. Build the Tree using the Root of this Javadoc run.

     *

     * @param configuration the configuration of the doclet.

     * @param noDeprecated Don't add deprecated classes in the class tree, if

     * true.

     */

    public ClassTree(BaseConfiguration configuration, boolean noDeprecated) {

        this.configuration = configuration;

        this.utils = configuration.utils;

        Messages messages = configuration.getMessages();

        messages.notice("doclet.Building_Tree");

        comparator = utils.makeClassUseComparator();

        baseAnnotationTypes = new TreeSet<>(comparator);

        baseEnums = new TreeSet<>(comparator);

        baseClasses = new TreeSet<>(comparator);

        baseInterfaces = new TreeSet<>(comparator);

        buildTree(configuration.getIncludedTypeElements());

    }

    /**

     * Constructor. Build the Tree using the Root of this Javadoc run.

     *

     * @param docEnv the DocletEnvironment.

     * @param configuration The current configuration of the doclet.

     */

    public ClassTree(DocletEnvironment docEnv, BaseConfiguration configuration) {

        this.configuration = configuration;

        this.utils = configuration.utils;

        comparator = utils.makeClassUseComparator();

        baseAnnotationTypes = new TreeSet<>(comparator);

        baseEnums = new TreeSet<>(comparator);

        baseClasses = new TreeSet<>(comparator);

        baseInterfaces = new TreeSet<>(comparator);

        buildTree(configuration.getIncludedTypeElements());

    }

    /**

     * Constructor. Build the tree for the given array of classes.

     *

     * @param classesSet a set of classes

     * @param configuration The current configuration of the doclet.

     */

    public ClassTree(SortedSet<TypeElement>classesSet, BaseConfiguration configuration) {

        this.configuration = configuration;

        this.utils = configuration.utils;

        comparator = utils.makeClassUseComparator();

        baseAnnotationTypes = new TreeSet<>(comparator);

        baseEnums = new TreeSet<>(comparator);

        baseClasses = new TreeSet<>(comparator);

        baseInterfaces = new TreeSet<>(comparator);

        buildTree(classesSet);

    }

    /**

     * Generate mapping for the sub-classes for every class in this run.

     * Return the sub-class set for java.lang.Object which will be having

     * sub-class listing for itself and also for each sub-class itself will

     * have their own sub-class lists.

     *

     * @param classes all the classes in this run.

     */

    private void buildTree(Iterable<TypeElement> classes) {

        for (TypeElement aClass : classes) {

            // In the tree page (e.g overview-tree.html) do not include

            // information of classes which are deprecated or are a part of a

            // deprecated package.

            if (configuration.nodeprecated &&

                    (utils.isDeprecated(aClass) ||

                    utils.isDeprecated(utils.containingPackage(aClass)))) {

                continue;

            }

                continue;

            }

            if (utils.isEnum(aClass)) {

                processType(aClass, configuration, baseEnums, subEnums);

            } else if (utils.isClass(aClass)) {

                processType(aClass, configuration, baseClasses, subClasses);

            } else if (utils.isInterface(aClass)) {

                processInterface(aClass);

            } else if (utils.isAnnotationType(aClass)) {

                processType(aClass, configuration, baseAnnotationTypes,

                    subAnnotationTypes);

            }

        }

    }

    /**

     * For the class passed map it to its own sub-class listing.

     * For the Class passed, get the super class,

     * if superclass is non null, (it is not "java.lang.Object")

     * get the "value" from the hashmap for this key Class

     * if entry not found create one and get that.

     * add this Class as a sub class in the set

     * Recurse till hits java.lang.Object Null SuperClass.

     *

     * @param typeElement for which sub class mapping is to be generated.

     * @param configuration the current configuration of the doclet.

     */

    private void processType(TypeElement typeElement, BaseConfiguration configuration,

            Collection<TypeElement> bases, Map<TypeElement, SortedSet<TypeElement>> subs) {

        TypeElement superclass = utils.getFirstVisibleSuperClassAsTypeElement(typeElement);

        if (superclass != null) {

            if (!add(subs, superclass, typeElement)) {

                return;

            } else {

                processType(superclass, configuration, bases, subs);

            }

        } else {     // typeElement is java.lang.Object, add it once to the set

            if (!bases.contains(typeElement)) {

                bases.add(typeElement);

            }

        }

        Set<TypeMirror> intfacs = utils.getAllInterfaces(typeElement);

        for (TypeMirror intfac : intfacs) {

            add(implementingClasses, utils.asTypeElement(intfac), typeElement);

        }

    }

    /**

     * For the interface passed get the interfaces which it extends, and then

     * put this interface in the sub-interface set of those interfaces. Do it

     * recursively. If a interface doesn't have super-interface just attach

     * that interface in the set of all the baseInterfaces.

     *

     * @param typeElement Interface under consideration.

     */

    private void processInterface(TypeElement typeElement) {

        List<? extends TypeMirror> intfacs = typeElement.getInterfaces();

        if (!intfacs.isEmpty()) {

            for (TypeMirror intfac : intfacs) {

                if (!add(subInterfaces, utils.asTypeElement(intfac), typeElement)) {

                    return;

                } else {

                    processInterface(utils.asTypeElement(intfac));   // Recurse

                }

            }

        } else {

            // we need to add all the interfaces who do not have

            // super-interfaces to baseInterfaces set to traverse them

            if (!baseInterfaces.contains(typeElement)) {

                baseInterfaces.add(typeElement);

            }

        }

    }

    /**

     * Adjust the Class Tree. Add the class interface  in to it's super classes

     * or super interface's sub-interface set.

     *

     * @param map the entire map.

     * @param superclass java.lang.Object or the super-interface.

     * @param typeElement sub-interface to be mapped.

     * @returns boolean true if class added, false if class already processed.

     */

    private boolean add(Map<TypeElement, SortedSet<TypeElement>> map, TypeElement superclass, TypeElement typeElement) {

        SortedSet<TypeElement> sset = map.computeIfAbsent(superclass, s ->  new TreeSet<>(comparator));

        if (sset.contains(typeElement)) {

            return false;

        } else {

            sset.add(typeElement);

        }

        return true;

    }

    /**

     * From the map return the set of sub-classes or sub-interfaces. If set

     * is null create a new one and return it.

     *

     * @param map The entire map.

     * @param typeElement class for which the sub-class set is requested.

     * @returns a list of sub classes.

     */

    private SortedSet<TypeElement> get(Map<TypeElement, SortedSet<TypeElement>> map, TypeElement typeElement) {

        return map.computeIfAbsent(typeElement, t ->  new TreeSet<>(comparator));

    }

    /**

     *  Return the sub-class set for the class passed.

     *

     * @param typeElement class whose sub-class set is required.

     */

    public SortedSet<TypeElement> subClasses(TypeElement typeElement) {

        return get(subClasses, typeElement);

    }

    /**

     *  Return the sub-interface set for the interface passed.

     *

     * @param typeElement interface whose sub-interface set is required.

     */

    public SortedSet<TypeElement> subInterfaces(TypeElement typeElement) {

        return get(subInterfaces, typeElement);

    }

    /**

     *  Return the set of classes which implement the interface passed.

     *

     * @param typeElement interface whose implementing-classes set is required.

     */

    public SortedSet<TypeElement> implementingClasses(TypeElement typeElement) {

        SortedSet<TypeElement> result = get(implementingClasses, typeElement);

        SortedSet<TypeElement> intfcs = allSubClasses(typeElement, false);

        // If class x implements a subinterface of typeElement, then it follows

        // that class x implements typeElement.

        Iterator<TypeElement> subInterfacesIter = intfcs.iterator();

        while (subInterfacesIter.hasNext()) {

            Iterator<TypeElement> implementingClassesIter

                    = implementingClasses(subInterfacesIter.next()).iterator();

            while (implementingClassesIter.hasNext()) {

                TypeElement c = implementingClassesIter.next();

                if (!result.contains(c)) {

                    result.add(c);

                }

            }

        }

        return result;

    }

    /**

     *  Return the sub-class/interface set for the class/interface passed.

     *

     * @param typeElement class/interface whose sub-class/interface set is required.

     * @param isEnum true if the subClasses should be forced to come from the

     * enum tree.

     */

    public SortedSet<TypeElement> directSubClasses(TypeElement typeElement, boolean isEnum) {

        return directSubClasses0(typeElement, isEnum);

    }

    private SortedSet<TypeElement> directSubClasses0(TypeElement typeElement, boolean isEnum) {

        if (isEnum) {

            return get(subEnums, typeElement);

        } else if (utils.isAnnotationType(typeElement)) {

            return get(subAnnotationTypes, typeElement);

        } else if (utils.isInterface(typeElement)) {

            return get(subInterfaces, typeElement);

        } else if (utils.isClass(typeElement)) {

            return get(subClasses, typeElement);

        } else {

            return Collections.emptySortedSet();

        }

    }

    /**

     * Return a set of all direct or indirect, sub-classes and subInterfaces

     * of the TypeElement argument.

     *

     * @param typeElement TypeElement whose sub-classes or sub-interfaces are requested.

     * @param isEnum true if the subClasses should be forced to come from the

     * enum tree.

     */

    public SortedSet<TypeElement> allSubClasses(TypeElement typeElement, boolean isEnum) {

        // new entries added to the set are searched as well, this is

        // really a work queue.

        List<TypeElement> list = new ArrayList<>(directSubClasses(typeElement, isEnum));

        for (int i = 0; i < list.size(); i++) {

            TypeElement te = list.get(i);

            SortedSet<TypeElement> tset = directSubClasses0(te, isEnum);

            for (TypeElement tte : tset) {

                if (!list.contains(tte)) {

                    list.add(tte);

                }

            }

        }

        SortedSet<TypeElement> out = new TreeSet<>(comparator);

        out.addAll(list);

        return out;

    }

    /**

     *  Return a set of base classes. This will have only one element namely

     *  the TypeElement for java.lang.Object, since this is the base class for all

     *  classes.

     */

    public SortedSet<TypeElement> baseClasses() {

        return baseClasses;

    }

    /**

     *  Return the set of base interfaces. This is the set of interfaces

     * which do not have super-interface.

     */

    public SortedSet<TypeElement> baseInterfaces() {

        return baseInterfaces;

    }

    /**

     *  Return the set of base enums. This is the set of enums

     *  which do not have super-enums.

     */

    public SortedSet<TypeElement> baseEnums() {

        return baseEnums;

    }

    /**

     * Return the set of base annotation types. This is the set

     * of annotation types which do not have super-annotation types.

     */

    public SortedSet<TypeElement> baseAnnotationTypes() {

        return baseAnnotationTypes;

    }

}