/*
 * Copyright (c) 2011 Google Inc.
 *
 * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
 * Public License v1.0 which accompanies this distribution, and is available at
 *
 * http://www.eclipse.org/legal/epl-v10.html
 */
package com.google.eclipse.protobuf.ui.parser;

import org.antlr.runtime.CharStream;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.xtext.nodemodel.impl.NodeModelBuilder;
import org.eclipse.xtext.parser.IParseResult;
import org.eclipse.xtext.parser.ParseResult;
import org.eclipse.xtext.ui.editor.preferences.IPreferenceStoreAccess;

import com.google.eclipse.protobuf.parser.UnknownSyntaxProtobuf;
import com.google.eclipse.protobuf.parser.antlr.ProtobufParser;
import com.google.eclipse.protobuf.protobuf.Protobuf;
import com.google.eclipse.protobuf.ui.preferences.misc.MiscellaneousPreferences;
import com.google.inject.Inject;

/**
 * @author alruiz@google.com (Alex Ruiz)
 */
public class PreferenceDrivenProtobufParser extends ProtobufParser {
  @Inject private IPreferenceStoreAccess storeAccess;

  @Override protected IParseResult doParse(String ruleName, CharStream in, NodeModelBuilder builder,
      int initialLookAhead) {
    IParseResult result = super.doParse(ruleName, in, builder, initialLookAhead);
    MiscellaneousPreferences preferences = new MiscellaneousPreferences(storeAccess);
    if (preferences.isGoogleInternal() && hasUnknownSyntax(result)) {
      return new ParseResult(new UnknownSyntaxProtobuf(), result.getRootNode(), false);
    }
    return result;
  }

  private boolean hasUnknownSyntax(IParseResult result) {
    EObject rootObj = result.getRootASTElement();
    if (rootObj instanceof Protobuf) {
      Protobuf root = (Protobuf) result.getRootASTElement();
      return root == null || root.getSyntax() == null;
    }
    
    return rootObj == null;
  }
}