/*

 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.

 * Copyright (C) 2011, 2013-2021 The JavaParser Team.

 *

 * This file is part of JavaParser.

 *

 * JavaParser can be used either under the terms of

 * a) the GNU Lesser General Public License as published by

 *     the Free Software Foundation, either version 3 of the License, or

 *     (at your option) any later version.

 * b) the terms of the Apache License

 *

 * You should have received a copy of both licenses in LICENCE.LGPL and

 * LICENCE.APACHE. Please refer to those files for details.

 *

 * JavaParser 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 Lesser General Public License for more details.

 */

package com.github.javaparser.ast.expr;

import com.github.javaparser.TokenRange;

import com.github.javaparser.ast.AllFieldsConstructor;

import com.github.javaparser.ast.Generated;

import com.github.javaparser.ast.Node;

import com.github.javaparser.ast.nodeTypes.NodeWithExpression;

import com.github.javaparser.ast.nodeTypes.NodeWithType;

import com.github.javaparser.ast.observer.ObservableProperty;

import com.github.javaparser.ast.type.ClassOrInterfaceType;

import com.github.javaparser.ast.type.ReferenceType;

import com.github.javaparser.ast.visitor.CloneVisitor;

import com.github.javaparser.ast.visitor.GenericVisitor;

import com.github.javaparser.ast.visitor.VoidVisitor;

import com.github.javaparser.metamodel.InstanceOfExprMetaModel;

import com.github.javaparser.metamodel.JavaParserMetaModel;

import com.github.javaparser.metamodel.OptionalProperty;

import java.util.Optional;

import java.util.function.Consumer;

import static com.github.javaparser.utils.Utils.assertNotNull;

/**

 * <h1>The instanceof statement</h1>

 *

 * <h2>Java ?? to 13</h2>

 * The {@code instanceof} expression is a

 * <a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.20">relational operator</a>,

 * evaluating to true if the object on the left hand side

 * is an instance of the type ({@link ReferenceType}) on the right hand side.

 * <br>

 * <br>

 * Example:

 * <br>{@code tool instanceof Drill}

 * <br>

 * <br>This is then used wherever a conditional/boolean value can be used. For example:

 * <br>

 * <pre>{@code if (obj instanceof String) {

 *     String s = (String) obj;

 *     // use s

 * }}</pre>

 * <br>

 * <h2>Java 14</h2>

 * Since JDK14, it is possible to bind a variable that is cast to the type being tested against.

 * This is referred to as a {@code Pattern} within <a href="https://bugs.openjdk.java.net/browse/JDK-8181287">JEP305</a>,

 * and avoids the need to cast to the desired type.

 * <br>

 * Example:

 * <br>{@code tool instanceof Drill d}

 * <br>

 * <br>This is then used wherever a conditional/boolean value can be used. The scope of the variable created can vary, and is defined further within

 * <a href="https://bugs.openjdk.java.net/browse/JDK-8181287">JEP305</a>.

 * <br>

 * <pre>{@code if (obj instanceof String s) {

 *     // can use s here

 * } else {

 *     // can't use s here

 * }}</pre>

 * <br>

 * <br>

 * <h3>JDK14 Grammar</h3>

 * Per JEP305:

 * <br>

 * <pre>{@code RelationalExpression:

 *      ...

 *      RelationalExpression instanceof ReferenceType

 *      RelationalExpression instanceof Pattern

 *

 * Pattern:

 *      ReferenceType Identifier}</pre>

 *

 * @author Julio Vilmar Gesser

 *

 * @see com.github.javaparser.ast.expr.PatternExpr

 * @see <a href="https://bugs.openjdk.java.net/browse/JDK-8181287">JEP305: https://bugs.openjdk.java.net/browse/JDK-8181287</a>

 * @see <a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.20">https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.20</a>

 */

public class InstanceOfExpr extends Expression implements NodeWithType<InstanceOfExpr, ReferenceType>, NodeWithExpression<InstanceOfExpr> {

    private Expression expression;

    @OptionalProperty

    private PatternExpr pattern;

    private ReferenceType type;

    public InstanceOfExpr() {

        this(null, new NameExpr(), new ClassOrInterfaceType(), null);

    }

    public InstanceOfExpr(final Expression expression, final ReferenceType type) {

        this(null, expression, type, null);

    }

    @AllFieldsConstructor

    public InstanceOfExpr(final Expression expression, final ReferenceType type, final PatternExpr pattern) {

        this(null, expression, type, pattern);

    }

    /**

     * This constructor is used by the parser and is considered private.

     */

    @Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator")

    public InstanceOfExpr(TokenRange tokenRange, Expression expression, ReferenceType type, PatternExpr pattern) {

        super(tokenRange);

        setExpression(expression);

        setType(type);

        setPattern(pattern);

        customInitialization();

    }

    /**

     * Helper method which, if this is an expression with a pattern, returns the identifier/name.

     * <br>

     * <br>For example:

     * <br>{@code obj instanceof String stringName}

     * <br>

     * <br>In this example, {@code getName()} returns {@code stringName}

     */

    public Optional<SimpleName> getName() {

        if (pattern == null) {

            return Optional.empty();

        } else {

            return Optional.of(pattern.getName());

        }

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.AcceptGenerator")

    public <R, A> R accept(final GenericVisitor<R, A> v, final A arg) {

        return v.visit(this, arg);

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.AcceptGenerator")

    public <A> void accept(final VoidVisitor<A> v, final A arg) {

        v.visit(this, arg);

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")

    public InstanceOfExpr asInstanceOfExpr() {

        return this;

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.CloneGenerator")

    public InstanceOfExpr clone() {

        return (InstanceOfExpr) accept(new CloneVisitor(), null);

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public Expression getExpression() {

        return expression;

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.GetMetaModelGenerator")

    public InstanceOfExprMetaModel getMetaModel() {

        return JavaParserMetaModel.instanceOfExprMetaModel;

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public Optional<PatternExpr> getPattern() {

        return Optional.ofNullable(pattern);

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public ReferenceType getType() {

        return type;

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")

    public void ifInstanceOfExpr(Consumer<InstanceOfExpr> action) {

        action.accept(this);

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")

    public boolean isInstanceOfExpr() {

        return true;

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")

    public boolean remove(Node node) {

        if (node == null)

            return false;

        if (pattern != null) {

            if (node == pattern) {

                removePattern();

                return true;

            }

        }

        return super.remove(node);

    }

    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")

    public InstanceOfExpr removePattern() {

        return setPattern((PatternExpr) null);

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.ReplaceMethodGenerator")

    public boolean replace(Node node, Node replacementNode) {

        if (node == null)

            return false;

        if (node == expression) {

            setExpression((Expression) replacementNode);

            return true;

        }

        if (pattern != null) {

            if (node == pattern) {

                setPattern((PatternExpr) replacementNode);

                return true;

            }

        }

        if (node == type) {

            setType((ReferenceType) replacementNode);

            return true;

        }

        return super.replace(node, replacementNode);

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public InstanceOfExpr setExpression(final Expression expression) {

        assertNotNull(expression);

        if (expression == this.expression) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);

        if (this.expression != null)

            this.expression.setParentNode(null);

        this.expression = expression;

        setAsParentNodeOf(expression);

        return this;

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public InstanceOfExpr setPattern(final PatternExpr pattern) {

        if (pattern == this.pattern) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.PATTERN, this.pattern, pattern);

        if (this.pattern != null)

            this.pattern.setParentNode(null);

        this.pattern = pattern;

        setAsParentNodeOf(pattern);

        return this;

    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")

    public InstanceOfExpr setType(final ReferenceType type) {

        assertNotNull(type);

        if (type == this.type) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.TYPE, this.type, type);

        if (this.type != null)

            this.type.setParentNode(null);

        this.type = type;

        setAsParentNodeOf(type);

        return this;

    }

    @Override

    @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator")

    public Optional<InstanceOfExpr> toInstanceOfExpr() {

        return Optional.of(this);

    }

}