/*
 * Copyright (c) 2018, 2020, 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.util;

import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Elements;
import javax.lang.model.util.SimpleElementVisitor14;
import java.lang.ref.SoftReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;
import java.util.stream.Collectors;

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

This class computes the main data structure for the doclet's
operations. Essentially, the implementation encapsulating the
javax.lang.models view of what can be documented about a
type element's members.

The general operations are as follows:

Members: these are the members from jx.l.m's view but
are structured along the kinds of this class.

Extra Members: these are members enclosed in an undocumented
package-private type element, and may not be linkable (or documented),
however, the members of such a type element may be documented, as if
declared in the sub type, only if the enclosing type is not being
documented by a filter such as -public, -protected, etc.

Visible Members: these are the members that are "visible"
and available and should be documented, in a type element.

The basic rule for computation: when considering a type element,
besides its immediate direct types and interfaces, the computation
should not expand to any other type in the inheritance hierarchy.

This table generates all the data structures it needs for each
type, as its own view, and will present some form of this to the
doclet as and when required to.
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.
/**
 * This class computes the main data structure for the doclet's
 * operations. Essentially, the implementation encapsulating the
 * javax.lang.models view of what can be documented about a
 * type element's members.
 * <p>
 * The general operations are as follows:
 * <p>
 * Members: these are the members from jx.l.m's view but
 * are structured along the kinds of this class.
 * <p>
 * Extra Members: these are members enclosed in an undocumented
 * package-private type element, and may not be linkable (or documented),
 * however, the members of such a type element may be documented, as if
 * declared in the sub type, only if the enclosing type is not being
 * documented by a filter such as -public, -protected, etc.
 * <p>
 * Visible Members: these are the members that are "visible"
 * and available and should be documented, in a type element.
 * <p>
 * The basic rule for computation: when considering a type element,
 * besides its immediate direct types and interfaces, the computation
 * should not expand to any other type in the inheritance hierarchy.
 * <p>
 * This table generates all the data structures it needs for each
 * type, as its own view, and will present some form of this to the
 * doclet as and when required to.
 *
 * <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 class VisibleMemberTable {

    public enum Kind {
        INNER_CLASSES,
        ENUM_CONSTANTS,
        FIELDS,
        CONSTRUCTORS,
        METHODS,
        ANNOTATION_TYPE_MEMBER_OPTIONAL,
        ANNOTATION_TYPE_MEMBER_REQUIRED,
        PROPERTIES;

        public static final EnumSet<Kind> summarySet = EnumSet.range(INNER_CLASSES, METHODS);
        public static final EnumSet<Kind> detailSet = EnumSet.range(ENUM_CONSTANTS, METHODS);
    }

    final TypeElement te;
    final TypeElement parent;

    final BaseConfiguration config;
    final BaseOptions options;
    final Utils utils;
    final VisibleMemberCache mcache;

    private List<VisibleMemberTable> allSuperclasses;
    private List<VisibleMemberTable> allSuperinterfaces;
    private List<VisibleMemberTable> parents;

    private Map<Kind, List<Element>> visibleMembers = null;
    private Map<ExecutableElement, PropertyMembers> propertyMap = new HashMap<>();

    // Keeps track of method overrides
    Map<ExecutableElement, OverridingMethodInfo> overriddenMethodTable
            = new LinkedHashMap<>();

    protected VisibleMemberTable(TypeElement typeElement, BaseConfiguration configuration,
                                 VisibleMemberCache mcache) {
        config = configuration;
        utils = configuration.utils;
        options = configuration.getOptions();
        te = typeElement;
        parent = utils.getSuperClass(te);
        this.mcache = mcache;
        allSuperclasses = new ArrayList<>();
        allSuperinterfaces = new ArrayList<>();
        parents = new ArrayList<>();
    }

    private synchronized void ensureInitialized() {
        if (visibleMembers != null)
            return;

        visibleMembers = new EnumMap<>(Kind.class);
        for (Kind kind : Kind.values()) {
            visibleMembers.put(kind, new ArrayList<>());
        }
        computeParents();
        computeVisibleMembers();
    }

    List<VisibleMemberTable> getAllSuperclasses() {
        ensureInitialized();
        return allSuperclasses;
    }

    List<VisibleMemberTable> getAllSuperinterfaces() {
        ensureInitialized();
        return allSuperinterfaces;
    }

    
Returns a list of all visible enclosed members of a type element,
and inherited members.

Notes:
a. The list may or may not contain simple overridden methods.
A simple overridden method is one that overrides a super method
with no specification changes as indicated by the existence of a
sole @inheritDoc or devoid of any API comments.

b.The list may contain (extra) members, inherited by inaccessible
super types, primarily package private types. These members are
required to be documented in the subtype when the super type is
not documented.
Params:
kind – the member kind
Returns:
a list of all visible members/**
     * Returns a list of all visible enclosed members of a type element,
     * and inherited members.
     * <p>
     * Notes:
     * a. The list may or may not contain simple overridden methods.
     * A simple overridden method is one that overrides a super method
     * with no specification changes as indicated by the existence of a
     * sole &commat;inheritDoc or devoid of any API comments.
     * <p>
     * b.The list may contain (extra) members, inherited by inaccessible
     * super types, primarily package private types. These members are
     * required to be documented in the subtype when the super type is
     * not documented.
     *
     * @param kind the member kind
     * @return a list of all visible members
     */
    public List<? extends Element> getAllVisibleMembers(Kind kind) {
        ensureInitialized();
        return visibleMembers.getOrDefault(kind, Collections.emptyList());
    }

    
Returns a list of visible enclosed members of a specified kind,
filtered by the specified predicate.
Params:
kind – the member kind
p – the predicate used to filter the output
Returns:
a list of visible enclosed members/**
     * Returns a list of visible enclosed members of a specified kind,
     * filtered by the specified predicate.
     * @param kind the member kind
     * @param p the predicate used to filter the output
     * @return a list of visible enclosed members
     */
    public List<? extends Element> getVisibleMembers(Kind kind, Predicate<Element> p) {
        ensureInitialized();

        return visibleMembers.getOrDefault(kind, Collections.emptyList()).stream()
                .filter(p)
                .collect(Collectors.toList());
    }

    
Returns a list of all enclosed members including any extra members.
Typically called by various builders.
Params:
kind – the member kind
Returns:
a list of visible enclosed members/**
     * Returns a list of all enclosed members including any extra members.
     * Typically called by various builders.
     *
     * @param kind the member kind
     * @return a list of visible enclosed members
     */
    public List<? extends Element> getVisibleMembers(Kind kind) {
        Predicate<Element> declaredAndLeafMembers = e -> {
            TypeElement encl = utils.getEnclosingTypeElement(e);
            return encl == te || utils.isUndocumentedEnclosure(encl);
        };
        return getVisibleMembers(kind, declaredAndLeafMembers);
    }

    
Returns a list of visible enclosed members of given kind,
declared in this type element, and does not include
any inherited members or extra members.
Returns:
a list of visible enclosed members in this type/**
     * Returns a list of visible enclosed members of given kind,
     * declared in this type element, and does not include
     * any inherited members or extra members.
     *
     * @return a list of visible enclosed members in this type
     */
    public List<? extends Element> getMembers(Kind kind) {
        Predicate<Element> onlyLocallyDeclaredMembers = e -> utils.getEnclosingTypeElement(e) == te;
        return getVisibleMembers(kind, onlyLocallyDeclaredMembers);
    }

    
Returns the overridden method, if it is simply overriding or the
method is a member of a package private type, this method is
primarily used to determine the location of a possible comment.
Params:
e – the method to check
Returns:
the method found or null/**
     * Returns the overridden method, if it is simply overriding or the
     * method is a member of a package private type, this method is
     * primarily used to determine the location of a possible comment.
     *
     * @param e the method to check
     * @return the method found or null
     */
    public ExecutableElement getOverriddenMethod(ExecutableElement e) {
        ensureInitialized();

        OverridingMethodInfo found = overriddenMethodTable.get(e);
        if (found != null
                && (found.simpleOverride || utils.isUndocumentedEnclosure(utils.getEnclosingTypeElement(e)))) {
            return found.overrider;
        }
        return null;
    }

    
Returns the simply overridden method.
Params:
e – the method to check
Returns:
the overridden method or null/**
     * Returns the simply overridden method.
     * @param e the method to check
     * @return the overridden method or null
     */
    public ExecutableElement getSimplyOverriddenMethod(ExecutableElement e) {
        ensureInitialized();

        OverridingMethodInfo found = overriddenMethodTable.get(e);
        if (found != null && found.simpleOverride) {
            return found.overrider;
        }
        return null;
    }

    
Returns a set of visible type elements in this type element's lineage.

This method returns the super-types in the inheritance
order C, B, A, j.l.O. The super-interfaces however are
alpha sorted and appended to the resulting set.
Returns:
the list of visible classes in this map./**
     * Returns a set of visible type elements in this type element's lineage.
     * <p>
     * This method returns the super-types in the inheritance
     * order C, B, A, j.l.O. The super-interfaces however are
     * alpha sorted and appended to the resulting set.
     *
     * @return the list of visible classes in this map.
     */
    public Set<TypeElement> getVisibleTypeElements() {
        ensureInitialized();
        Set<TypeElement> result = new LinkedHashSet<>();

        // Add this type element first.
        result.add(te);

        // Add the super classes.
        allSuperclasses.stream()
                .map(vmt -> vmt.te)
                .forEach(result::add);

        // ... and finally the sorted super interfaces.
        allSuperinterfaces.stream()
                .map(vmt -> vmt.te)
                .sorted(utils.comparators.makeGeneralPurposeComparator())
                .forEach(result::add);

        return result;
    }

    
Returns true if this table contains visible members.
Returns:
true if visible members are present./**
     * Returns true if this table contains visible members.
     *
     * @return true if visible members are present.
     */
    public boolean hasVisibleMembers() {
        for (Kind kind : Kind.values()) {
            if (hasVisibleMembers(kind))
                return true;
        }
        return false;
    }

    
Returns true if this table contains visible members of
the specified kind, including inherited members.
Returns:
true if visible members are present./**
     * Returns true if this table contains visible members of
     * the specified kind, including inherited members.
     *
     * @return true if visible members are present.
     */
    public boolean hasVisibleMembers(Kind kind) {
        ensureInitialized();
        List<Element> elements = visibleMembers.get(kind);
        return elements != null && !elements.isEmpty();
    }

    
Returns the property field associated with the property method.
Params:
propertyMethod – the identifying property method
Returns:
the field or null if absent/**
     * Returns the property field associated with the property method.
     * @param propertyMethod the identifying property method
     * @return the field or null if absent
     */
    public VariableElement getPropertyField(ExecutableElement propertyMethod) {
        ensureInitialized();
        PropertyMembers pm =  propertyMap.get(propertyMethod);
        return pm == null ? null : pm.field;
    }

    
Returns the getter method associated with the property method.
Params:
propertyMethod – the identifying property method
Returns:
the getter or null if absent/**
     * Returns the getter method associated with the property method.
     * @param propertyMethod the identifying property method
     * @return the getter or null if absent
     */
    public ExecutableElement getPropertyGetter(ExecutableElement propertyMethod) {
        ensureInitialized();
        PropertyMembers pm =  propertyMap.get(propertyMethod);
        return pm == null ? null : pm.getter;
    }

    
Returns the setter method associated with the property method.
Params:
propertyMethod – the identifying property method
Returns:
the setter or null if absent/**
     * Returns the setter method associated with the property method.
     * @param propertyMethod the identifying property method
     * @return the setter or null if absent
     */
    public ExecutableElement getPropertySetter(ExecutableElement propertyMethod) {
        ensureInitialized();
        PropertyMembers pm =  propertyMap.get(propertyMethod);
        return pm == null ? null : pm.setter;
    }

    private void computeParents() {
        // suppress parents of annotation types
        if (utils.isAnnotationType(te)) {
            return;
        }

        for (TypeMirror intfType : te.getInterfaces()) {
            TypeElement intfc = utils.asTypeElement(intfType);
            if (intfc != null) {
                VisibleMemberTable vmt = mcache.getVisibleMemberTable(intfc);
                allSuperinterfaces.add(vmt);
                parents.add(vmt);
                allSuperinterfaces.addAll(vmt.getAllSuperinterfaces());
            }
        }

        if (parent != null) {
            VisibleMemberTable vmt = mcache.getVisibleMemberTable(parent);
            allSuperclasses.add(vmt);
            allSuperclasses.addAll(vmt.getAllSuperclasses());
            // Add direct super interfaces of a super class, if any.
            allSuperinterfaces.addAll(vmt.getAllSuperinterfaces());
            parents.add(vmt);
        }
    }

    private void computeVisibleMembers() {

        // Note: these have some baggage, and are redundant,
        // allow this to be GC'ed.
        LocalMemberTable lmt = new LocalMemberTable();

        for (Kind k : Kind.values()) {
            computeVisibleMembers(lmt, k);
        }
        // All members have been computed, compute properties.
        computeVisibleProperties(lmt);
    }


    void computeVisibleMembers(LocalMemberTable lmt, Kind kind) {
        switch (kind) {
            case FIELDS: case INNER_CLASSES:
                computeVisibleFieldsAndInnerClasses(lmt, kind);
                return;

            case METHODS:
                computeVisibleMethods(lmt);
                return;

            // Defer properties related computations for later.
            case PROPERTIES:
                return;

            default:
                List<Element> list = lmt.getOrderedMembers(kind).stream()
                        .filter(this::mustDocument)
                        .collect(Collectors.toList());
                visibleMembers.put(kind, Collections.unmodifiableList(list));
                break;
        }
    }

    private boolean mustDocument(Element e) {
        return !utils.hasHiddenTag(e) && utils.shouldDocument(e);
    }

    private boolean allowInheritedMembers(Element e, Kind kind, LocalMemberTable lmt) {
        return isInherited(e) && !isMemberHidden(e, kind, lmt);
    }

    private boolean isInherited(Element e) {
        if (utils.isPrivate(e))
            return false;

        if (utils.isPackagePrivate(e))
            // Allowed iff this type-element is in the same package as the element
            return utils.containingPackage(e).equals(utils.containingPackage(te));

        return true;
    }

    private boolean isMemberHidden(Element inheritedMember, Kind kind, LocalMemberTable lmt) {
        Elements elementUtils = config.docEnv.getElementUtils();
        switch(kind) {
            default:
                List<Element> list = lmt.getMembers(inheritedMember, kind);
                if (list.isEmpty())
                    return false;
                return elementUtils.hides(list.get(0), inheritedMember);
            case METHODS: case CONSTRUCTORS: // Handled elsewhere.
                throw new IllegalArgumentException("incorrect kind");
        }
    }

    private void computeVisibleFieldsAndInnerClasses(LocalMemberTable lmt, Kind kind) {
        Set<Element> result = new LinkedHashSet<>();
        for (VisibleMemberTable pvmt : parents) {
            result.addAll(pvmt.getAllVisibleMembers(kind));
        }

        // Filter out members in the inherited list that are hidden
        // by this type or should not be inherited at all.
        List<Element> list = result.stream()
                .filter(e -> allowInheritedMembers(e, kind, lmt))
                .collect(Collectors.toList());

        // Prefix local results first
        list.addAll(0, lmt.getOrderedMembers(kind));

        // Filter out elements that should not be documented
        list = list.stream()
                .filter(this::mustDocument)
                .collect(Collectors.toList());

        visibleMembers.put(kind, Collections.unmodifiableList(list));
    }

    private void computeVisibleMethods(LocalMemberTable lmt) {
        Set<Element> inheritedMethods = new LinkedHashSet<>();
        Map<ExecutableElement, List<ExecutableElement>> overriddenByTable = new HashMap<>();
        for (VisibleMemberTable pvmt : parents) {
            // Merge the lineage overrides into local table
            pvmt.overriddenMethodTable.entrySet().forEach(e -> {
                OverridingMethodInfo p = e.getValue();
                if (!p.simpleOverride) { // consider only real overrides
                    List<ExecutableElement> list = overriddenByTable.computeIfAbsent(p.overrider,
                            k -> new ArrayList<>());
                    list.add(e.getKey());
                }
            });
            inheritedMethods.addAll(pvmt.getAllVisibleMembers(Kind.METHODS));
        }

        // Filter out inherited methods that:
        // a. cannot override (private instance members)
        // b. are overridden and should not be visible in this type
        // c. are hidden in the type being considered
        // see allowInheritedMethods, which performs the above actions
        List<Element> list = inheritedMethods.stream()
                .filter(e -> allowInheritedMethods((ExecutableElement) e, overriddenByTable, lmt))
                .collect(Collectors.toList());

        // Filter out the local methods, that do not override or simply
        // overrides a super method, or those methods that should not
        // be visible.
        Predicate<ExecutableElement> isVisible = m -> {
            OverridingMethodInfo p = overriddenMethodTable.getOrDefault(m, null);
            return p == null || !p.simpleOverride;
        };
        List<Element> localList = lmt.getOrderedMembers(Kind.METHODS)
                .stream()
                .map(m -> (ExecutableElement)m)
                .filter(isVisible)
                .collect(Collectors.toList());

        // Merge the above lists, making sure the local methods precede the others
        list.addAll(0, localList);

        // Final filtration of elements
        list = list.stream()
                .filter(this::mustDocument)
                .collect(Collectors.toList());

        visibleMembers.put(Kind.METHODS, Collections.unmodifiableList(list));

        // Copy over overridden tables from the lineage, and finish up.
        for (VisibleMemberTable pvmt : parents) {
            overriddenMethodTable.putAll(pvmt.overriddenMethodTable);
        }
        overriddenMethodTable = Collections.unmodifiableMap(overriddenMethodTable);
    }

    boolean isEnclosureInterface(Element e) {
        TypeElement enclosing = utils.getEnclosingTypeElement(e);
        return utils.isInterface(enclosing);
    }

    boolean allowInheritedMethods(ExecutableElement inheritedMethod,
                                  Map<ExecutableElement, List<ExecutableElement>> inheritedOverriddenTable,
                                  LocalMemberTable lmt) {
        if (!isInherited(inheritedMethod))
            return false;

        final boolean haveStatic = utils.isStatic(inheritedMethod);
        final boolean inInterface = isEnclosureInterface(inheritedMethod);

        // Static methods in interfaces are never documented.
        if (haveStatic && inInterface) {
            return false;
        }

        // Multiple-Inheritance: remove the interface method that may have
        // been overridden by another interface method in the hierarchy
        //
        // Note: The following approach is very simplistic and is compatible
        // with old VMM. A future enhancement, may include a contention breaker,
        // to correctly eliminate those methods that are merely definitions
        // in favor of concrete overriding methods, for instance those that have
        // API documentation and are not abstract OR default methods.
        if (inInterface) {
            List<ExecutableElement> list = inheritedOverriddenTable.get(inheritedMethod);
            if (list != null) {
                boolean found = list.stream()
                        .anyMatch(this::isEnclosureInterface);
                if (found)
                    return false;
            }
        }

        Elements elementUtils = config.docEnv.getElementUtils();

        // Check the local methods in this type.
        List<Element> lMethods = lmt.getMembers(inheritedMethod, Kind.METHODS);
        for (Element le : lMethods) {
            ExecutableElement lMethod = (ExecutableElement) le;
            // Ignore private methods or those methods marked with
            // a "hidden" tag.
            if (utils.isPrivate(lMethod))
                continue;

            // Remove methods that are "hidden", in JLS terms.
            if (haveStatic && utils.isStatic(lMethod) &&
                    elementUtils.hides(lMethod, inheritedMethod)) {
                return false;
            }

            // Check for overriding methods.
            if (elementUtils.overrides(lMethod, inheritedMethod,
                    utils.getEnclosingTypeElement(lMethod))) {

                // Disallow package-private super methods to leak in
                TypeElement encl = utils.getEnclosingTypeElement(inheritedMethod);
                if (utils.isUndocumentedEnclosure(encl)) {
                    overriddenMethodTable.computeIfAbsent(lMethod,
                            l -> new OverridingMethodInfo(inheritedMethod, false));
                    return false;
                }

                TypeMirror inheritedMethodReturn = inheritedMethod.getReturnType();
                TypeMirror lMethodReturn = lMethod.getReturnType();
                boolean covariantReturn =
                        lMethodReturn.getKind() == TypeKind.DECLARED
                        && inheritedMethodReturn.getKind() == TypeKind.DECLARED
                        && !utils.typeUtils.isSameType(lMethodReturn, inheritedMethodReturn)
                        && utils.typeUtils.isSubtype(lMethodReturn, inheritedMethodReturn);
                boolean simpleOverride = covariantReturn ? false : utils.isSimpleOverride(lMethod);
                overriddenMethodTable.computeIfAbsent(lMethod,
                        l -> new OverridingMethodInfo(inheritedMethod, simpleOverride));
                return simpleOverride;
            }
        }
        return true;
    }

    /*
     * This class encapsulates the details of local members, orderedMembers
     * contains the members in the declaration order, additionally a
     * HashMap is maintained for performance optimization to lookup
     * members. As a future enhancement is perhaps to consolidate the ordering
     * into a Map, capturing the insertion order, thereby eliminating an
     * ordered list.
     */
    class LocalMemberTable {

        // Maintains declaration order
        private final Map<Kind, List<Element>> orderedMembers;

        // Performance optimization
        private final Map<Kind, Map<String, List<Element>>> memberMap;

        LocalMemberTable() {
            orderedMembers = new EnumMap<>(Kind.class);
            memberMap = new EnumMap<>(Kind.class);

            List<? extends Element> elements = te.getEnclosedElements();
            for (Element e : elements) {
                if (options.noDeprecated() && utils.isDeprecated(e)) {
                    continue;
                }
                switch (e.getKind()) {
                    case CLASS:
                    case INTERFACE:
                    case ENUM:
                    case ANNOTATION_TYPE:
                    case RECORD:
                        addMember(e, Kind.INNER_CLASSES);
                        break;
                    case FIELD:
                        addMember(e, Kind.FIELDS);
                        break;
                    case METHOD:
                        if (utils.isAnnotationType(te)) {
                            ExecutableElement ee = (ExecutableElement) e;
                            addMember(e, ee.getDefaultValue() == null
                                    ? Kind.ANNOTATION_TYPE_MEMBER_REQUIRED
                                    : Kind.ANNOTATION_TYPE_MEMBER_OPTIONAL);
                        } else {
                            addMember(e, Kind.METHODS);
                        }
                        break;
                    case CONSTRUCTOR:
                            addMember(e, Kind.CONSTRUCTORS);
                        break;
                    case ENUM_CONSTANT:
                        addMember(e, Kind.ENUM_CONSTANTS);
                        break;
                }
            }

            // Freeze the data structures
            for (Kind kind : Kind.values()) {
                orderedMembers.computeIfPresent(kind, (k, v) -> Collections.unmodifiableList(v));
                orderedMembers.computeIfAbsent(kind, t -> Collections.emptyList());

                memberMap.computeIfPresent(kind, (k, v) -> Collections.unmodifiableMap(v));
                memberMap.computeIfAbsent(kind, t -> Collections.emptyMap());
            }
        }

        @SuppressWarnings("preview")
        String getMemberKey(Element e) {
            return new SimpleElementVisitor14<String, Void>() {
                @Override
                public String visitExecutable(ExecutableElement e, Void aVoid) {
                    return e.getSimpleName() + ":" + e.getParameters().size();
                }

                @Override
                protected String defaultAction(Element e, Void aVoid) {
                    return e.getSimpleName().toString();
                }
            }.visit(e);
        }

        void addMember(Element e, Kind kind) {
            List<Element> list = orderedMembers.computeIfAbsent(kind, k -> new ArrayList<>());
            list.add(e);

            Map<String, List<Element>> map = memberMap.computeIfAbsent(kind, k -> new HashMap<>());
            list = map.computeIfAbsent(getMemberKey(e), l -> new ArrayList<>());
            list.add(e);
        }

        List<Element> getOrderedMembers(Kind kind) {
            return orderedMembers.get(kind);
        }

        List<Element> getMembers(Element e, Kind kind) {
            String key = getMemberKey(e);
            return getMembers(key, kind);
        }

        List<Element> getMembers(String key, Kind kind) {
            Map <String, List<Element>> map = memberMap.get(kind);
            return map.getOrDefault(key, Collections.emptyList());
        }

        List<Element> getPropertyMethods(String methodName, int argcount) {
            return getMembers(methodName + ":" + argcount, Kind.METHODS).stream()
                    .filter(m -> (utils.isPublic(m) || utils.isProtected(m)))
                    .collect(Collectors.toList());
        }
    }

    
The properties triad for a property method.
/**
     * The properties triad for a property method.
     */
    static class PropertyMembers {
        final VariableElement field;
        final ExecutableElement getter;
        final ExecutableElement setter;

        PropertyMembers(VariableElement field, ExecutableElement getter, ExecutableElement setter) {
            this.field = field;
            this.getter = getter;
            this.setter = setter;
        }

        public String toString() {
            return ("field: " + field + ", getter: " + getter + ", setter: " + setter);
        }
    }

    /*
     * JavaFX convention notes.
     * A JavaFX property-method is a method, which ends with "Property" in
     * its name, takes no parameters and typically returns a subtype of javafx.beans.
     * ReadOnlyProperty, in the strictest sense. However, it may not always
     * be possible for the doclet to have access to j.b.ReadOnlyProperty,
     * for this reason the strict check is disabled via an undocumented flag.
     *
     * Note, a method should not be considered as a property-method,
     * if it satisfied the previously stated conditions AND if the
     * method begins with "set", "get" or "is".
     *
     * Supposing we have  {@code BooleanProperty acmeProperty()}, then the
     * property-name  is "acme".
     *
     * Property field, one may or may not exist and could be private, and
     * should match the property-method.
     *
     * A property-setter is a method starting with "set", and the
     * first character of the upper-cased starting character of the property name, the
     * method must take 1 argument and must return a <code>void</code>.
     *
     * Using the above example {@code void setAcme(Something s)} can be
     * considered as a property-setter of the property "acme".
     *
     * A property-getter is a method  starting with "get" and the first character
     * upper-cased property-name, having no parameters. A method that does not take any
     * parameters and starting with "is" and an upper-cased property-name,
     * returning a primitive type boolean or BooleanProperty can also be
     * considered as a getter, however there must be only one getter for every property.
     *
     * For example {@code Object getAcme()} is a property-getter, and
     * {@code boolean isFoo()}
     */
    private void computeVisibleProperties(LocalMemberTable lmt) {
        if (!options.javafx())
            return;

        PropertyUtils pUtils = config.propertyUtils;
        List<ExecutableElement> list = visibleMembers.getOrDefault(Kind.METHODS, Collections.emptyList())
                .stream()
                .map(m -> (ExecutableElement)m)
                .filter(pUtils::isPropertyMethod)
                .collect(Collectors.toList());

        visibleMembers.put(Kind.PROPERTIES, Collections.unmodifiableList(list));

        List<ExecutableElement> propertyMethods = list.stream()
                .filter(e -> utils.getEnclosingTypeElement(e) == te)
                .collect(Collectors.toList());

        // Compute additional properties related sundries.
        for (ExecutableElement propertyMethod : propertyMethods) {
            String baseName = pUtils.getBaseName(propertyMethod);
            List<Element> flist = lmt.getMembers(baseName, Kind.FIELDS);
            Element field = flist.isEmpty() ? null : flist.get(0);

            Element getter = null, setter = null;
            List<Element> found = lmt.getPropertyMethods(pUtils.getGetName(propertyMethod), 0);
            if (!found.isEmpty()) {
                // Getters have zero params, no overloads! pick the first.
                getter = found.get(0);
            }
            if (getter == null) {
                // Check if isProperty methods are present ?
                found = lmt.getPropertyMethods(pUtils.getIsName(propertyMethod), 0);
                if (!found.isEmpty()) {
                    String propertyTypeName = propertyMethod.getReturnType().toString();
                    // Check if the return type of property method matches an isProperty method.
                    if (pUtils.hasIsMethod(propertyMethod)) {
                        // Getters have zero params, no overloads!, pick the first.
                        getter = found.get(0);
                    }
                }
            }
            found = lmt.getPropertyMethods(pUtils.getSetName(propertyMethod), 1);
            if (found != null) {
                for (Element e : found) {
                    if (pUtils.isValidSetterMethod((ExecutableElement)e)) {
                        setter = e;
                        break;
                    }
                }
            }

            propertyMap.put(propertyMethod, new PropertyMembers((VariableElement)field,
                    (ExecutableElement)getter, (ExecutableElement)setter));

            // Debugging purposes
            // System.out.println("te: " + te + ": " + utils.getEnclosingTypeElement(propertyMethod) +
            //        ":" + propertyMethod.toString() + "->" + propertyMap.get(propertyMethod));
        }
    }


    // Future cleanups

    Map<ExecutableElement, SoftReference<ImplementedMethods>> implementMethodsFinders = new HashMap<>();

    private ImplementedMethods getImplementedMethodsFinder(ExecutableElement method) {
        SoftReference<ImplementedMethods> imf = implementMethodsFinders.get(method);
        // IMF does not exist or referent was gc'ed away ?
        if (imf == null || imf.get() == null) {
            imf = new SoftReference<>(new ImplementedMethods(method));
            implementMethodsFinders.put(method, imf);
        }
        return imf.get();
    }

    public List<ExecutableElement> getImplementedMethods(ExecutableElement method) {
        ImplementedMethods imf = getImplementedMethodsFinder(method);
        return imf.getImplementedMethods().stream()
                .filter(m -> getSimplyOverriddenMethod(m) == null)
                .collect(Collectors.toList());
    }

    public TypeMirror getImplementedMethodHolder(ExecutableElement method,
                                                 ExecutableElement implementedMethod) {
        ImplementedMethods imf = getImplementedMethodsFinder(method);
        return imf.getMethodHolder(implementedMethod);
    }

    private class ImplementedMethods {

        private final Map<ExecutableElement, TypeMirror> interfaces = new HashMap<>();
        private final List<ExecutableElement> methlist = new ArrayList<>();

        public ImplementedMethods(ExecutableElement method) {
            TypeElement typeElement = utils.getEnclosingTypeElement(method);
            Set<TypeMirror> intfacs = utils.getAllInterfaces(typeElement);
            /*
             * Search for the method in the list of interfaces. If found check if it is
             * overridden by any other subinterface method which this class
             * implements. If it is not overridden, add it in the method list.
             * Do this recursively for all the extended interfaces for each interface
             * from the list.
             */
            for (TypeMirror interfaceType : intfacs) {
                ExecutableElement found = utils.findMethod(utils.asTypeElement(interfaceType), method);
                if (found != null) {
                    removeOverriddenMethod(found);
                    if (!overridingMethodFound(found)) {
                        methlist.add(found);
                        interfaces.put(found, interfaceType);
                    }
                }
            }
        }

        
Return the list of interface methods which the method passed in the
constructor is implementing. The search/build order is as follows:
1. Search in all the immediate interfaces which this method's class is
   implementing. Do it recursively for the superinterfaces as well.
2. Traverse all the superclasses and search recursively in the
   interfaces which those superclasses implement.

Returns:
SortedSet of implemented methods./**
         * Return the list of interface methods which the method passed in the
         * constructor is implementing. The search/build order is as follows:
         * <pre>
         * 1. Search in all the immediate interfaces which this method's class is
         *    implementing. Do it recursively for the superinterfaces as well.
         * 2. Traverse all the superclasses and search recursively in the
         *    interfaces which those superclasses implement.
         *</pre>
         *
         * @return SortedSet<ExecutableElement> of implemented methods.
         */
        List<ExecutableElement> getImplementedMethods() {
            return methlist;
        }

        TypeMirror getMethodHolder(ExecutableElement ee) {
            return interfaces.get(ee);
        }

        
Search in the method list and check if it contains a method which
is overridden by the method as parameter.  If found, remove the
overridden method from the method list.
Params:
method – Is this method overriding a method in the method list./**
         * Search in the method list and check if it contains a method which
         * is overridden by the method as parameter.  If found, remove the
         * overridden method from the method list.
         *
         * @param method Is this method overriding a method in the method list.
         */
        private void removeOverriddenMethod(ExecutableElement method) {
            TypeElement overriddenClass = utils.overriddenClass(method);
            if (overriddenClass != null) {
                for (int i = 0; i < methlist.size(); i++) {
                    TypeElement te = utils.getEnclosingTypeElement(methlist.get(i));
                    if (te == overriddenClass || utils.isSubclassOf(overriddenClass, te)) {
                        methlist.remove(i);  // remove overridden method
                        return;
                    }
                }
            }
        }

        
Search in the already found methods' list and check if it contains
a method which is overriding the method parameter or is the method
parameter itself.
Params:
method – method to be searched/**
         * Search in the already found methods' list and check if it contains
         * a method which is overriding the method parameter or is the method
         * parameter itself.
         *
         * @param method method to be searched
         */
        private boolean overridingMethodFound(ExecutableElement method) {
            TypeElement containingClass = utils.getEnclosingTypeElement(method);
            for (ExecutableElement listmethod : methlist) {
                if (containingClass == utils.getEnclosingTypeElement(listmethod)) {
                    // it's the same method.
                    return true;
                }
                TypeElement te = utils.overriddenClass(listmethod);
                if (te == null) {
                    continue;
                }
                if (te == containingClass || utils.isSubclassOf(te, containingClass)) {
                    return true;
                }
            }
            return false;
        }
    }

    
A simple container to encapsulate an overriding method
and the type of override.
/**
     * A simple container to encapsulate an overriding method
     * and the type of override.
     */
    static class OverridingMethodInfo {
        final ExecutableElement overrider;
        final boolean simpleOverride;

        public OverridingMethodInfo(ExecutableElement overrider, boolean simpleOverride) {
            this.overrider = overrider;
            this.simpleOverride = simpleOverride;
        }

        @Override
        public String toString() {
            return "OverridingMethodInfo[" + overrider + ",simple:" + simpleOverride + "]";
        }
    }
}