/*

 * 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.stmt;

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.expr.BooleanLiteralExpr;

import com.github.javaparser.ast.expr.Expression;

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

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.DerivedProperty;

import com.github.javaparser.metamodel.IfStmtMetaModel;

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;

/**

 * An if-then-else statement. The else is optional.

 * <br>In {@code if(a==5) hurray() else boo();} the condition is a==5,

 * hurray() is the thenStmt, and boo() is the elseStmt.

 *

 * @author Julio Vilmar Gesser

 */

public class IfStmt extends Statement implements NodeWithCondition<IfStmt> {

    private Expression condition;

    private Statement thenStmt;

    @OptionalProperty

    private Statement elseStmt;

    public IfStmt() {

        this(null, new BooleanLiteralExpr(), new ReturnStmt(), null);

    }

    @AllFieldsConstructor

    public IfStmt(final Expression condition, final Statement thenStmt, final Statement elseStmt) {

        this(null, condition, thenStmt, elseStmt);

    }

    /**

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

     */

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

    public IfStmt(TokenRange tokenRange, Expression condition, Statement thenStmt, Statement elseStmt) {

        super(tokenRange);

        setCondition(condition);

        setThenStmt(thenStmt);

        setElseStmt(elseStmt);

        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 Expression getCondition() {

        return condition;

    }

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

    public Optional<Statement> getElseStmt() {

        return Optional.ofNullable(elseStmt);

    }

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

    public Statement getThenStmt() {

        return thenStmt;

    }

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

    public IfStmt setCondition(final Expression condition) {

        assertNotNull(condition);

        if (condition == this.condition) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.CONDITION, this.condition, condition);

        if (this.condition != null)

            this.condition.setParentNode(null);

        this.condition = condition;

        setAsParentNodeOf(condition);

        return this;

    }

    /**

     * Sets the elseStmt

     *

     * @param elseStmt the elseStmt, can be null

     * @return this, the IfStmt

     */

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

    public IfStmt setElseStmt(final Statement elseStmt) {

        if (elseStmt == this.elseStmt) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.ELSE_STMT, this.elseStmt, elseStmt);

        if (this.elseStmt != null)

            this.elseStmt.setParentNode(null);

        this.elseStmt = elseStmt;

        setAsParentNodeOf(elseStmt);

        return this;

    }

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

    public IfStmt setThenStmt(final Statement thenStmt) {

        assertNotNull(thenStmt);

        if (thenStmt == this.thenStmt) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.THEN_STMT, this.thenStmt, thenStmt);

        if (this.thenStmt != null)

            this.thenStmt.setParentNode(null);

        this.thenStmt = thenStmt;

        setAsParentNodeOf(thenStmt);

        return this;

    }

    @Override

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

    public boolean remove(Node node) {

        if (node == null)

            return false;

        if (elseStmt != null) {

            if (node == elseStmt) {

                removeElseStmt();

                return true;

            }

        }

        return super.remove(node);

    }

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

    public IfStmt removeElseStmt() {

        return setElseStmt((Statement) null);

    }

    /**

     * This method returns true if the then branch (which should be always present) is a block statement.

     */

    @DerivedProperty

    public boolean hasThenBlock() {

        return thenStmt instanceof BlockStmt;

    }

    /**

     * This method returns true if the If Statement has an else branch and that branch is a block statement.

     */

    @DerivedProperty

    public boolean hasElseBlock() {

        return elseStmt instanceof BlockStmt;

    }

    /**

     * This method returns true if the If Statement has an else branch and that branch is another If Statement.

     */

    @DerivedProperty

    public boolean hasCascadingIfStmt() {

        return elseStmt instanceof IfStmt;

    }

    /**

     * This method returns true if the If Statement has an else branch.

     */

    @DerivedProperty

    public boolean hasElseBranch() {

        return elseStmt != null;

    }

    @Override

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

    public IfStmt clone() {

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

    }

    @Override

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

    public IfStmtMetaModel getMetaModel() {

        return JavaParserMetaModel.ifStmtMetaModel;

    }

    @Override

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

    public boolean replace(Node node, Node replacementNode) {

        if (node == null)

            return false;

        if (node == condition) {

            setCondition((Expression) replacementNode);

            return true;

        }

        if (elseStmt != null) {

            if (node == elseStmt) {

                setElseStmt((Statement) replacementNode);

                return true;

            }

        }

        if (node == thenStmt) {

            setThenStmt((Statement) replacementNode);

            return true;

        }

        return super.replace(node, replacementNode);

    }

    @Override

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

    public boolean isIfStmt() {

        return true;

    }

    @Override

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

    public IfStmt asIfStmt() {

        return this;

    }

    @Override

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

    public void ifIfStmt(Consumer<IfStmt> action) {

        action.accept(this);

    }

    @Override

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

    public Optional<IfStmt> toIfStmt() {

        return Optional.of(this);

    }

}