/*
 * @(#)$Id: SchemaProviderImpl.java,v 1.8 2001/05/24 16:53:51 Bear Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.relaxns.verifier;

import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.ErrorHandler;
import org.iso_relax.dispatcher.IslandVerifier;
import org.iso_relax.dispatcher.IslandSchema;
import org.iso_relax.dispatcher.impl.AbstractSchemaProviderImpl;
import com.sun.msv.relaxns.grammar.RELAXGrammar;
import com.sun.msv.relaxns.grammar.DeclImpl;
import com.sun.msv.grammar.Grammar;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.ReferenceExp;
import com.sun.msv.grammar.ExpressionPool;
//import com.sun.msv.verifier.regexp.REDocumentDeclaration;
import java.util.Iterator;

/**
 * implementation of SchemaProvider by using RELAX Grammar.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class SchemaProviderImpl extends AbstractSchemaProviderImpl {
	
	private final RELAXGrammar grammar;
	private final DeclImpl[] topLevel;
	/** top-level expression as AGM. */
	private final Expression topLevelExp;
	/** shared expression pool. */
	private final ExpressionPool pool;
	
	public IslandVerifier createTopLevelVerifier() {
		return new TREXIslandVerifier(
			new RulesAcceptor(
				new com.sun.msv.verifier.regexp.REDocumentDeclaration(topLevelExp,pool), topLevel ) );
	}
	
	/**
	 * creates SchemaProvider from generic Grammar (including TREX/RELAX Core)
	 */
	public static SchemaProviderImpl fromGrammar( Grammar grammar ) {
		if( grammar instanceof RELAXGrammar )
			return new SchemaProviderImpl( (RELAXGrammar)grammar );
		
		RELAXGrammar g = new RELAXGrammar(grammar.getPool());
		g.topLevel = grammar.getTopLevel();
		
		return new SchemaProviderImpl( g );
	}
	
	/**
	 * creates SchemaProvider from existing RELAXGrammar.
	 * 
	 * Since bind method is already called by RELAXNSReader,
	 * the application should not call bind method.
	 */
	public SchemaProviderImpl( RELAXGrammar grammar ) {
		this.grammar = grammar;
		this.pool = grammar.pool;
		this.topLevelExp = grammar.topLevel;
		this.topLevel = new DeclImpl[]{new DeclImpl("##start",grammar.topLevel)};
		
		// add all parsed modules into the provider.
		Iterator itr = grammar.moduleMap.keySet().iterator();
		while( itr.hasNext() ) {
			String namespaceURI = (String)itr.next();
			addSchema(
				namespaceURI, (IslandSchema)grammar.moduleMap.get(namespaceURI) );
		}
	}

	
	/** binds all IslandSchemata. */
	public boolean bind( ErrorHandler handler ) {
		ErrorHandlerFilter filter = new ErrorHandlerFilter(handler);
		
		try {
			Iterator itr = schemata.values().iterator();
			while( itr.hasNext() )
				((IslandSchema)itr.next()).bind( this, filter );
		} catch( SAXException e ) {
			// bind method may throw SAXException.
			return false;
		}
		
		return !filter.hadError;
	}
	
	private static class ErrorHandlerFilter implements ErrorHandler {
		private final ErrorHandler core;
		boolean hadError = false;
		
		ErrorHandlerFilter( ErrorHandler handler ) { this.core=handler; }
		
		public void fatalError( SAXParseException spe ) throws SAXException {
			error(spe);
		}
		
		public void error( SAXParseException spe ) throws SAXException {
			core.error(spe);
			hadError = true;
		}

		public void warning( SAXParseException spe ) throws SAXException {
			core.warning(spe);
		}
	}
}