/*

 * 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.body;

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.Expression;

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

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

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

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

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

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

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

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

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

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.JavaParserMetaModel;

import com.github.javaparser.metamodel.NonEmptyProperty;

import com.github.javaparser.metamodel.OptionalProperty;

import com.github.javaparser.metamodel.VariableDeclaratorMetaModel;

import com.github.javaparser.resolution.Resolvable;

import com.github.javaparser.resolution.declarations.ResolvedValueDeclaration;

import java.util.LinkedList;

import java.util.List;

import java.util.Optional;

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

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

/**

 * The declaration of a variable.<br>In {@code int x = 14, y = 3;} "int x = 14"  and "int y = 3"  are

 * VariableDeclarators.

 * <p>The type is on all of the variable declarators because, thanks to array brackets, each variable can have a different type.

 *

 * @author Julio Vilmar Gesser

 */

public class VariableDeclarator extends Node implements NodeWithType<VariableDeclarator, Type>, NodeWithSimpleName<VariableDeclarator>, Resolvable<ResolvedValueDeclaration> {

    private SimpleName name;

    @OptionalProperty

    @NonEmptyProperty

    private Expression initializer;

    private Type type;

    public VariableDeclarator() {

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

    }

    public VariableDeclarator(Type type, String variableName) {

        this(null, type, new SimpleName(variableName), null);

    }

    public VariableDeclarator(Type type, SimpleName name) {

        this(null, type, name, null);

    }

    public VariableDeclarator(Type type, String variableName, Expression initializer) {

        this(null, type, new SimpleName(variableName), initializer);

    }

    /**

     * Defines the declaration of a variable.

     *

     * @param name The identifier for this variable. IE. The variables name.

     * @param initializer What this variable should be initialized to. An {@link com.github.javaparser.ast.expr.AssignExpr}

     * is unnecessary as the {@code =} operator is already added.

     */

    @AllFieldsConstructor

    public VariableDeclarator(Type type, SimpleName name, Expression initializer) {

        this(null, type, name, initializer);

    }

    /**

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

     */

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

    public VariableDeclarator(TokenRange tokenRange, Type type, SimpleName name, Expression initializer) {

        super(tokenRange);

        setType(type);

        setName(name);

        setInitializer(initializer);

        customInitialization();

    }

    @Override

    protected void customInitialization() {

        // We register an observer on the type property. When it is changed the MaximumCommonType is changes as well,

        // because it is derived from the type of the variables it contains, for this reason we notify about the change

        register(new AstObserverAdapter() {

            @Override

            public void propertyChange(Node observedNode, ObservableProperty property, Object oldValue, Object newValue) {

                if (property == ObservableProperty.TYPE) {

                    VariableDeclarator vd = VariableDeclarator.this;

                    if (vd.getParentNode().isPresent() && vd.getParentNode().get() instanceof NodeWithVariables) {

                        NodeWithVariables<?> nodeWithVariables = (NodeWithVariables<?>) vd.getParentNode().get();

                        // We calculate the value the property will assume after the change will be completed

                        Optional<Type> currentMaxCommonType = nodeWithVariables.getMaximumCommonType();

                        List<Type> types = new LinkedList<>();

                        int index = nodeWithVariables.getVariables().indexOf(vd);

                        for (int i = 0; i < nodeWithVariables.getVariables().size(); i++) {

                            if (i == index) {

                                types.add((Type) newValue);

                            } else {

                                types.add(nodeWithVariables.getVariable(i).getType());

                            }

                        }

                        Optional<Type> newMaxCommonType = NodeWithVariables.calculateMaximumCommonType(types);

                        ((Node) nodeWithVariables).notifyPropertyChange(ObservableProperty.MAXIMUM_COMMON_TYPE, currentMaxCommonType.orElse(null), newMaxCommonType.orElse(null));

                    }

                }

            }

        });

    }

    @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 Optional<Expression> getInitializer() {

        return Optional.ofNullable(initializer);

    }

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

    public SimpleName getName() {

        return name;

    }

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

    public VariableDeclarator setName(final SimpleName name) {

        assertNotNull(name);

        if (name == this.name) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.NAME, this.name, name);

        if (this.name != null)

            this.name.setParentNode(null);

        this.name = name;

        setAsParentNodeOf(name);

        return this;

    }

    /**

     * Sets the initializer expression

     *

     * @param initializer the initializer expression, can be null

     * @return this, the VariableDeclarator

     */

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

    public VariableDeclarator setInitializer(final Expression initializer) {

        if (initializer == this.initializer) {

            return this;

        }

        notifyPropertyChange(ObservableProperty.INITIALIZER, this.initializer, initializer);

        if (this.initializer != null)

            this.initializer.setParentNode(null);

        this.initializer = initializer;

        setAsParentNodeOf(initializer);

        return this;

    }

    /**

     * Will create a {@link NameExpr} with the initializer param

     *

     * @param init the initializer expression, can be null

     * @return this, the VariableDeclarator

     */

    public VariableDeclarator setInitializer(String init) {

        return setInitializer(new NameExpr(assertNonEmpty(init)));

    }

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

    public Type getType() {

        return type;

    }

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

    public VariableDeclarator setType(final Type 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.RemoveMethodGenerator")

    public boolean remove(Node node) {

        if (node == null)

            return false;

        if (initializer != null) {

            if (node == initializer) {

                removeInitializer();

                return true;

            }

        }

        return super.remove(node);

    }

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

    public VariableDeclarator removeInitializer() {

        return setInitializer((Expression) null);

    }

    @Override

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

    public VariableDeclarator clone() {

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

    }

    @Override

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

    public VariableDeclaratorMetaModel getMetaModel() {

        return JavaParserMetaModel.variableDeclaratorMetaModel;

    }

    @Override

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

    public boolean replace(Node node, Node replacementNode) {

        if (node == null)

            return false;

        if (initializer != null) {

            if (node == initializer) {

                setInitializer((Expression) replacementNode);

                return true;

            }

        }

        if (node == name) {

            setName((SimpleName) replacementNode);

            return true;

        }

        if (node == type) {

            setType((Type) replacementNode);

            return true;

        }

        return super.replace(node, replacementNode);

    }

    @Override

    public ResolvedValueDeclaration resolve() {

        return getSymbolResolver().resolveDeclaration(this, ResolvedValueDeclaration.class);

    }

}