/*

 * 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.visitor.CloneVisitor;

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

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

import com.github.javaparser.metamodel.IntegerLiteralExprMetaModel;

import com.github.javaparser.metamodel.JavaParserMetaModel;

import java.util.Objects;

import java.util.Optional;

import java.util.function.Consumer;

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

/**

 * All ways to specify an int literal.

 *

 * <ul>

 * <li>{@code 8934}</li>

 * <li>{@code 0x01}</li>

 * <li>{@code 022}</li>

 * <li>{@code 0B10101010}</li>

 * </ul>

 *

 * @author Julio Vilmar Gesser

 */

public class IntegerLiteralExpr extends LiteralStringValueExpr {

    public static final String MAX_31_BIT_UNSIGNED_VALUE_AS_STRING = "2147483648";

    public static final long MAX_31_BIT_UNSIGNED_VALUE_AS_LONG = 2147483648L;

    public IntegerLiteralExpr() {

        this(null, "0");

    }

    @AllFieldsConstructor

    public IntegerLiteralExpr(final String value) {

        this(null, value);

    }

    /**

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

     */

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

    public IntegerLiteralExpr(TokenRange tokenRange, String value) {

        super(tokenRange, value);

        customInitialization();

    }

    /**

     * @deprecated This function is deprecated in favor of {@link #IntegerLiteralExpr(String)}. Please refer to the

     * {@link #asNumber()} function for valid formats and how to construct literals holding negative values.

     */

    @Deprecated

    public IntegerLiteralExpr(final int value) {

        this(null, String.valueOf(value));

    }

    @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.RemoveMethodGenerator")

    public boolean remove(Node node) {

        if (node == null)

            return false;

        return super.remove(node);

    }

    /**

     * @return the literal value as an integer while respecting different number representations

     * @deprecated This function has issues with corner cases, such as 2147483648, so please use {@link

     * IntegerLiteralExpr#asNumber()}. It will be made private or merged with {@link IntegerLiteralExpr#asNumber()} in

     * future releases

     */

    @Deprecated

    public int asInt() {

        String result = value.replaceAll("_", "");

        if (result.startsWith("0x") || result.startsWith("0X")) {

            return Integer.parseUnsignedInt(result.substring(2), 16);

        }

        if (result.startsWith("0b") || result.startsWith("0B")) {

            return Integer.parseUnsignedInt(result.substring(2), 2);

        }

        if (result.length() > 1 && result.startsWith("0")) {

            return Integer.parseUnsignedInt(result.substring(1), 8);

        }

        return Integer.parseInt(result);

    }

    /**

     * This function returns a representation of the literal value as a number. This will return an integer, except for

     * the case when the literal has the value {@code 2147483648}. This special literal is only allowed in the

     * expression {@code -2147483648} which represents <code>Integer.MIN_VALUE</code>). However 2147483648 (2^31)

     * is out of range of int, which is -(2^31) to (2^31)-1 and thus a long must be returned.

     *

     * <p>Note, that this function will NOT return a negative number if the literal was specified in decimal, since

     * according to the language specification (chapter 3.10.1) an expression such as {@code -1} is represented by

     * a unary expression with a minus operator and the literal {@code 1}. It is however possible to represent

     * negative numbers in a literal directly, i.e. by using the binary or hexadecimal representation. For example

     * {@code 0xffff_ffff} represents the value <code> -1</code>.

     *

     * @return the literal value as a number while respecting different number representations

     */

    public Number asNumber() {

        /*

         * we need to handle the special case for the literal 2147483648, which is used to

         * represent Integer.MIN_VALUE (-2147483648) as a combination of a UnaryExpr and an

         * IntegerLiteralExpr. However 2147483648 cannot be represented in an integer, so we

         * need to return a long

         */

        if (Objects.equals(value, MAX_31_BIT_UNSIGNED_VALUE_AS_STRING) && hasUnaryMinusAsParent(this)) {

            return MAX_31_BIT_UNSIGNED_VALUE_AS_LONG;

        } else {

            return asInt();

        }

    }

    /**

     * @deprecated This function is deprecated in favor of {@link #setValue(String)}. Please refer to the {@link

     * #asNumber()} function for valid formats and how to construct literals holding negative values.

     */

    @Deprecated

    public IntegerLiteralExpr setInt(int value) {

        this.value = String.valueOf(value);

        return this;

    }

    @Override

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

    public IntegerLiteralExpr clone() {

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

    }

    @Override

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

    public IntegerLiteralExprMetaModel getMetaModel() {

        return JavaParserMetaModel.integerLiteralExprMetaModel;

    }

    @Override

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

    public boolean replace(Node node, Node replacementNode) {

        if (node == null)

            return false;

        return super.replace(node, replacementNode);

    }

    @Override

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

    public boolean isIntegerLiteralExpr() {

        return true;

    }

    @Override

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

    public IntegerLiteralExpr asIntegerLiteralExpr() {

        return this;

    }

    @Override

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

    public void ifIntegerLiteralExpr(Consumer<IntegerLiteralExpr> action) {

        action.accept(this);

    }

    @Override

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

    public Optional<IntegerLiteralExpr> toIntegerLiteralExpr() {

        return Optional.of(this);

    }

}