/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.codegen;

import java.util.HashMap;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Repository of local variables.
 */
public class LocalVariables {
    private final AtomicInteger counter = new AtomicInteger(0);
    private final Map<String, LocalVariable> localVariables = new HashMap<>();

    LocalVariable createNew(TypeReference type, String name) {
        if (localVariables.containsKey(name)) {
            throw new IllegalStateException(String.format("Local variable %s already in scope", name));
        }
        LocalVariable localVariable = new LocalVariable(type, name, counter.getAndIncrement());
        localVariables.put(name, localVariable);
        // if 64 bit types we need to give it one more index
        if (type.simpleName().equals("double") || type.simpleName().equals("long")) {
            counter.incrementAndGet();
        }
        return localVariable;
    }

    public LocalVariable get(String name) {
        LocalVariable localVariable = localVariables.get(name);
        if (localVariable == null) {
            throw new NoSuchElementException("No variable '" + name + "' in scope");
        }
        return localVariable;
    }

    public static LocalVariables copy(LocalVariables original) {
        LocalVariables variables = new LocalVariables();
        variables.counter.set(original.counter.get());
        variables.localVariables.putAll(original.localVariables);
        return variables;
    }
}
