/*
 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.
 * Copyright (C) 2011, 2013-2024 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 static com.github.javaparser.utils.Utils.assertNotNull;

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;

/**
 * An assignment expression. It supports the operators that are found 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.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;
    }
}
