/*
* Copyright (C) 2013 The Rythm Engine project
* Gelin Luo <greenlaw110(at)gmail.com>
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.rythmengine.internal.dialect;
import org.rythmengine.internal.CodeBuilder;
import org.rythmengine.internal.IContext;
import org.rythmengine.internal.IDialect;
import org.rythmengine.internal.IParserFactory;
import org.rythmengine.logger.ILogger;
import org.rythmengine.logger.Logger;
import org.rythmengine.utils.S;
import java.util.Stack;
public class DialectManager {
protected final static ILogger logger = Logger.get(DialectManager.class);
final static IDialect[] defDialects = {
BasicRythm.INSTANCE,
SimpleRythm.INSTANCE,
Rythm.INSTANCE
};
public static IDialect getById(String id) {
for (IDialect d : defDialects) {
if (S.isEqual(id, d.id())) return d;
}
return null;
}
private static int indexOf(IDialect dialect) {
if (null == dialect) throw new NullPointerException();
for (int i = 0; i < defDialects.length; ++i) {
if (S.isEqual(dialect.id(), defDialects[i].id())) return i;
}
return -1;
}
private static IDialect nextAvailable(IDialect d) {
if (null == d) return defDialects[0];
int i = indexOf(d) + 1;
if (i >= defDialects.length) return null;
return defDialects[i];
}
private static final InheritableThreadLocal<Stack<IDialect>> cur = new InheritableThreadLocal<Stack<IDialect>>() {
@Override
protected Stack<IDialect> initialValue() {
return new Stack<IDialect>();
}
};
private static void push(IDialect dialect) {
if (null == dialect) throw new NullPointerException();
cur.get().push(dialect);
}
public static IDialect current() {
return cur.get().peek();
}
private static IDialect pop() {
Stack<IDialect> sd = cur.get();
IDialect d = sd.pop();
if (sd.isEmpty()) {
cur.remove();
}
return d;
}
public void beginParse(IContext ctx) {
CodeBuilder cb = ctx.getCodeBuilder();
IDialect d = cb.requiredDialect;
if (null == d) {
d = ctx.getDialect();
if (null != d) {
// try the next available
d = nextAvailable(d);
if (null == d) throw new NullPointerException("No dialect can process the template");
} else {
// guess the most capable
String template = ctx.getRemain();
for (IDialect d0 : defDialects) {
if (d0.isMyTemplate(template)) {
d = d0;
break;
}
}
}
}
ctx.setDialect(d);
push(d);
d.begin(ctx);
}
public void endParse(IContext ctx) {
IDialect d = ctx.getDialect();
d.end(ctx);
pop();
}
private void registerParserFactories(IDialect dialect, IParserFactory... factories) {
for (IParserFactory pf : factories) {
dialect.registerParserFactory(pf);
}
}
public void registerExternalParsers(String dialectId, IParserFactory... factories) {
if (null == dialectId) {
for (IDialect d : defDialects) {
registerParserFactories(d, factories);
}
} else {
IDialect d = getById(dialectId);
if (null != d) {
registerParserFactories(d, factories);
} else {
throw new IllegalArgumentException("Cannot find dialect by Id: " + dialectId);
}
}
}
}