/*

 * 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.observer.ObservableProperty;

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.AssignExprMetaModel;

import com.github.javaparser.metamodel.JavaParserMetaModel;

import com.github.javaparser.printer.Stringable;

import java.util.Optional;

import java.util.function.Consumer;

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

/**

 * An assignment expression. It supports the operators that are found the the AssignExpr.Operator enum.

 * <br>{@code a=5}

 * <br>{@code time+=500}

 * <br>{@code watch.time+=500}

 * <br>{@code (((time)))=100*60}

 * <br>{@code peanut[a]=true}

 *

 * @author Julio Vilmar Gesser

 */

public class AssignExpr extends Expression {

    public enum Operator implements Stringable {

        ASSIGN("="),

        PLUS("+="),

        MINUS("-="),

        MULTIPLY("*="),

        DIVIDE("/="),

        BINARY_AND("&="),

        BINARY_OR("|="),

        XOR("^="),

        REMAINDER("%="),

        LEFT_SHIFT("<<="),

        SIGNED_RIGHT_SHIFT(">>="),

        UNSIGNED_RIGHT_SHIFT(">>>=");

        private final String codeRepresentation;

        Operator(String codeRepresentation) {

            this.codeRepresentation = codeRepresentation;

        }

        public String asString() {

            return codeRepresentation;

        }

        public Optional<BinaryExpr.Operator> toBinaryOperator() {

            switch(this) {

                case PLUS:

                    return Optional.of(BinaryExpr.Operator.PLUS);

                case MINUS:

                    return Optional.of(BinaryExpr.Operator.MINUS);

                case MULTIPLY:

                    return Optional.of(BinaryExpr.Operator.MULTIPLY);

                case DIVIDE:

                    return Optional.of(BinaryExpr.Operator.DIVIDE);

                case BINARY_AND:

                    return Optional.of(BinaryExpr.Operator.BINARY_AND);

                case BINARY_OR:

                    return Optional.of(BinaryExpr.Operator.BINARY_OR);

                case XOR:

                    return Optional.of(BinaryExpr.Operator.XOR);

                case REMAINDER:

                    return Optional.of(BinaryExpr.Operator.REMAINDER);

                case LEFT_SHIFT:

                    return Optional.of(BinaryExpr.Operator.LEFT_SHIFT);

                case SIGNED_RIGHT_SHIFT:

                    return Optional.of(BinaryExpr.Operator.SIGNED_RIGHT_SHIFT);

                case UNSIGNED_RIGHT_SHIFT:

                    return Optional.of(BinaryExpr.Operator.UNSIGNED_RIGHT_SHIFT);

                default:

                    return Optional.empty();

            }

        }

    }

    private Expression target;

    private Expression value;

    private Operator operator;

    public AssignExpr() {

        this(null, new NameExpr(), new StringLiteralExpr(), Operator.ASSIGN);

    }

    @AllFieldsConstructor

    public AssignExpr(Expression target, Expression value, Operator operator) {

        this(null, target, value, operator);

    }

    /**

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

     */

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

    public AssignExpr(TokenRange tokenRange, Expression target, Expression value, Operator operator) {

        super(tokenRange);

        setTarget(target);

        setValue(value);

        setOperator(operator);

        customInitialization();

    }

    @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);

    }

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

    public Operator getOperator() {

        return operator;

    }

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

    public Expression getTarget() {

        return target;

    }

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

    public Expression getValue() {

        return value;

    }

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

    public AssignExpr setOperator(final Operator operator) {

        assertNotNull(operator);

        if (operator == this.operator) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, operator);

        this.operator = operator;

        return this;

    }

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

    public AssignExpr setTarget(final Expression target) {

        assertNotNull(target);

        if (target == this.target) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.TARGET, this.target, target);

        if (this.target != null)

            this.target.setParentNode(null);

        this.target = target;

        setAsParentNodeOf(target);

        return this;

    }

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

    public AssignExpr setValue(final Expression value) {

        assertNotNull(value);

        if (value == this.value) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.VALUE, this.value, value);

        if (this.value != null)

            this.value.setParentNode(null);

        this.value = value;

        setAsParentNodeOf(value);

        return this;

    }

    @Override

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

    public boolean remove(Node node) {

        if (node == null)

            return false;

        return super.remove(node);

    }

    @Override

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

    public AssignExpr clone() {

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

    }

    @Override

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

    public AssignExprMetaModel getMetaModel() {

        return JavaParserMetaModel.assignExprMetaModel;

    }

    @Override

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

    public boolean replace(Node node, Node replacementNode) {

        if (node == null)

            return false;

        if (node == target) {

            setTarget((Expression) replacementNode);

            return true;

        }

        if (node == value) {

            setValue((Expression) replacementNode);

            return true;

        }

        return super.replace(node, replacementNode);

    }

    @Override

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

    public boolean isAssignExpr() {

        return true;

    }

    @Override

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

    public AssignExpr asAssignExpr() {

        return this;

    }

    @Override

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

    public void ifAssignExpr(Consumer<AssignExpr> action) {

        action.accept(this);

    }

    @Override

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

    public Optional<AssignExpr> toAssignExpr() {

        return Optional.of(this);

    }

    /*

     * Returns true if the expression is an assignment context

     * https://docs.oracle.com/javase/specs/jls/se8/html/jls-5.html#jls-5.2

     * 5.2. Assignment Contexts: Assignment contexts allow the value of an expression to be assigned (§15.26) to a variable;...

     */

    @Override

    protected boolean isAssignmentContext() {

        return true;

    }

}