/*
 * 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.stmt;

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.NodeList;
import com.github.javaparser.ast.expr.Expression;
import com.github.javaparser.ast.nodeTypes.NodeWithStatements;
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.JavaParserMetaModel;
import com.github.javaparser.metamodel.OptionalProperty;
import com.github.javaparser.metamodel.SwitchEntryMetaModel;
import java.util.Optional;

/**
 * <h1>One case in a switch statement</h1>
 * The main Javadoc is in {@link SwitchStmt}
 * <h2>Java 1.0-11</h2>
 * <pre>{@code
 * switch (i) {
 *   case 1:
 *   case 2:
 *     System.out.println(444);
 *     break;
 *   default:
 *     System.out.println(0);
 * }
 * }</pre>
 * <br>
 * This contains three SwitchEntrys. All of them are of type STATEMENT_GROUP.
 * <ul>
 *     <li>The first one has label 1 and no statements.</li>
 *     <li>The second has label 2 and two statements (the println and the break).</li>
 *     <li>The third, the default, has no label and one statement.</li>
 * </ul>
 * <h2>Java 12-</h2>
 * <pre>{@code
 *     case 1 -> 15*15;
 *     case 2 -> { a++; b++; }
 *     case 3 -> throw new Exception();
 * }</pre>
 * These are three new variants.
 * <ul>
 *     <li>The first one is of type EXPRESSION and stores its {@link Expression} in an {@link ExpressionStmt} which is stored as the first and only statement in statements.</li>
 *     <li>The second one is of type BLOCK and stores its {@link BlockStmt} as the first and only statement in statements.</li>
 *     <li>The third one is of type THROWS_STATEMENT and stores its {@link ThrowStmt} as the first and only statement in statements.</li>
 * </ul>
 * <pre>{@code
 *     case MONDAY, FRIDAY, SUNDAY -> 6;
 * }</pre>
 * Multiple case labels are now allowed.
 * <pre>{@code
 *     case 16*16, 10+10 -> 6;
 * }</pre>
 * Many kinds of expressions are now allowed.
 *
 * @author Julio Vilmar Gesser
 * @see SwitchStmt
 * @see com.github.javaparser.ast.expr.SwitchExpr
 */
public class SwitchEntry extends Node implements NodeWithStatements<SwitchEntry> {

    public enum Type {
        STATEMENT_GROUP,
        EXPRESSION,
        BLOCK,
        THROWS_STATEMENT
    }

    private NodeList<Expression> labels;

    private NodeList<Statement> statements;

    private Type type;

    private boolean isDefault;

    @OptionalProperty
    private Expression guard;

    public SwitchEntry() {
        this(null, new NodeList<Expression>(), Type.STATEMENT_GROUP, new NodeList<>(), false, null);
    }

    /**
     * This constructor exists for backwards compatibility for code that instantiated `SwitchEntries` before
     * the `isDefault` and guard fields were added.
     */
    public SwitchEntry(
            final TokenRange tokenRange,
            final NodeList<Expression> labels,
            final Type type,
            final NodeList<Statement> statements) {
        this(tokenRange, labels, type, statements, false, null);
    }

    /**
     * This constructor exists for backwards compatibility for code that instantiated `SwitchEntries` before
     * the `isDefault` and guard fields were added.
     */
    public SwitchEntry(final NodeList<Expression> labels, final Type type, final NodeList<Statement> statements) {
        this(null, labels, type, statements, false, null);
    }

    @AllFieldsConstructor
    public SwitchEntry(
            final NodeList<Expression> labels,
            final Type type,
            final NodeList<Statement> statements,
            final boolean isDefault) {
        this(null, labels, type, statements, isDefault, null);
    }

    /**
     * This constructor is used by the parser and is considered private.
     */
    @Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator")
    public SwitchEntry(
            TokenRange tokenRange,
            NodeList<Expression> labels,
            Type type,
            NodeList<Statement> statements,
            boolean isDefault,
            Expression guard) {
        super(tokenRange);
        setLabels(labels);
        setType(type);
        setStatements(statements);
        setDefault(isDefault);
        setGuard(guard);
        customInitialization();
    }

    /**
     * This is required for the ConcreteSyntaxModel, specifically to determine whether this
     * entry uses the classic switch statement syntax (e.g. `case X: ...`) or the newer
     * switch expression syntax (`case X -> ...`).
     *
     * The entry type is STATEMENT_GROUP in the switch statement case and all other values
     * are for the various switch expressions.
     */
    @DerivedProperty
    public boolean isSwitchStatementEntry() {
        return type == Type.STATEMENT_GROUP;
    }

    @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 NodeList<Expression> getLabels() {
        return labels;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public NodeList<Statement> getStatements() {
        return statements;
    }

    /**
     * Sets the label
     *
     * @param labels the label, can be null
     * @return this, the SwitchEntry
     */
    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public SwitchEntry setLabels(final NodeList<Expression> labels) {
        assertNotNull(labels);
        if (labels == this.labels) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.LABELS, this.labels, labels);
        if (this.labels != null) this.labels.setParentNode(null);
        this.labels = labels;
        setAsParentNodeOf(labels);
        return this;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public SwitchEntry setStatements(final NodeList<Statement> statements) {
        assertNotNull(statements);
        if (statements == this.statements) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.STATEMENTS, this.statements, statements);
        if (this.statements != null) this.statements.setParentNode(null);
        this.statements = statements;
        setAsParentNodeOf(statements);
        return this;
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")
    public boolean remove(Node node) {
        if (node == null) {
            return false;
        }
        if (guard != null) {
            if (node == guard) {
                removeGuard();
                return true;
            }
        }
        for (int i = 0; i < labels.size(); i++) {
            if (labels.get(i) == node) {
                labels.remove(i);
                return true;
            }
        }
        for (int i = 0; i < statements.size(); i++) {
            if (statements.get(i) == node) {
                statements.remove(i);
                return true;
            }
        }
        return super.remove(node);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.CloneGenerator")
    public SwitchEntry clone() {
        return (SwitchEntry) accept(new CloneVisitor(), null);
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.GetMetaModelGenerator")
    public SwitchEntryMetaModel getMetaModel() {
        return JavaParserMetaModel.switchEntryMetaModel;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public Type getType() {
        return type;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public SwitchEntry setType(final Type type) {
        assertNotNull(type);
        if (type == this.type) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
        this.type = type;
        return this;
    }

    @Override
    @Generated("com.github.javaparser.generator.core.node.ReplaceMethodGenerator")
    public boolean replace(Node node, Node replacementNode) {
        if (node == null) {
            return false;
        }
        if (guard != null) {
            if (node == guard) {
                setGuard((Expression) replacementNode);
                return true;
            }
        }
        for (int i = 0; i < labels.size(); i++) {
            if (labels.get(i) == node) {
                labels.set(i, (Expression) replacementNode);
                return true;
            }
        }
        for (int i = 0; i < statements.size(); i++) {
            if (statements.get(i) == node) {
                statements.set(i, (Statement) replacementNode);
                return true;
            }
        }
        return super.replace(node, replacementNode);
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public boolean isDefault() {
        return isDefault;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public SwitchEntry setDefault(final boolean isDefault) {
        if (isDefault == this.isDefault) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.DEFAULT, this.isDefault, isDefault);
        this.isDefault = isDefault;
        return this;
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public Optional<Expression> getGuard() {
        return Optional.ofNullable(guard);
    }

    @Generated("com.github.javaparser.generator.core.node.PropertyGenerator")
    public SwitchEntry setGuard(final Expression guard) {
        if (guard == this.guard) {
            return this;
        }
        notifyPropertyChange(ObservableProperty.GUARD, this.guard, guard);
        if (this.guard != null) this.guard.setParentNode(null);
        this.guard = guard;
        setAsParentNodeOf(guard);
        return this;
    }

    @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator")
    public SwitchEntry removeGuard() {
        return setGuard((Expression) null);
    }

    /**
     * This constructor is used by the parser and is considered private.
     */
    @Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator")
    public SwitchEntry(
            TokenRange tokenRange,
            NodeList<Expression> labels,
            Type type,
            NodeList<Statement> statements,
            boolean isDefault) {
        super(tokenRange);
        setLabels(labels);
        setType(type);
        setStatements(statements);
        setDefault(isDefault);
        customInitialization();
    }
}
