/*
 * 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.apache.jena.sparql.sse.writers;

import java.util.Iterator ;
import java.util.Map ;

import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.sparql.core.Prologue ;
import org.apache.jena.sparql.sse.Tags ;
import org.apache.jena.sparql.util.FmtUtils ;

public class WriterBasePrefix
{
    private static final int NL = WriterLib.NL ;
    private static final int NoNL = WriterLib.NoNL ;
    private static final int NoSP = WriterLib.NoSP ;

    public static interface Fmt { void format() ; }
    //public static Fmt fmt = new Fmt(){ public void format() {}} ;

    /** Output, write the thing with formater fmt */
    public static void output(IndentedWriter iWriter, Fmt fmt, Prologue prologue)
    {
        boolean printBase = false ;

        boolean closeBase = printBase(iWriter, prologue) ;
        boolean closePrefix = printPrefix(iWriter, prologue) ;
        
        if ( fmt != null )
            fmt.format() ;

        if ( closeBase )
            WriterLib.finish(iWriter, Tags.tagBase) ;
        if ( closePrefix )
            WriterLib.finish(iWriter, Tags.tagPrefix) ;
        iWriter.ensureStartOfLine() ;
        iWriter.flush();
    }
    
    private static boolean printBase(IndentedWriter iWriter, Prologue prologue)
    {
        String baseURI = prologue.getBaseURI() ;
        
        if ( baseURI != null )
        {
            WriterLib.start(iWriter, Tags.tagBase, NoNL) ;   
            iWriter.print(FmtUtils.stringForURI(baseURI)) ;
            iWriter.println();
            return true ;
        }
        return false ;
    }
    
    private static boolean printPrefix(IndentedWriter iWriter, Prologue prologue)
    {
        PrefixMapping prefixMapping = prologue.getPrefixMapping() ;

        if ( prefixMapping != null )
        {
            Map<String, String> m = prefixMapping.getNsPrefixMap() ;
            if ( ! m.isEmpty() )
            {
                int s = iWriter.getCol() ;
                WriterLib.start(iWriter, Tags.tagPrefix, NoNL) ;
                WriterLib.start(iWriter) ;

                // Indent to this col.
                int len = iWriter.getCurrentOffset() ;

                iWriter.incIndent(len) ;
                Iterator<String> iter = m.keySet().iterator();
                boolean first = true ;
                for ( ; iter.hasNext() ; )
                {
                    if ( ! first )
                        iWriter.println() ;
                    first = false ;
                    String prefix = iter.next();
                    String uri = prefixMapping.getNsPrefixURI(prefix) ;
                    // Base relative URI = but not prefix mappings!
                    uri = FmtUtils.stringForURI(uri, prologue.getBaseURI()) ;
                    WriterLib.start(iWriter) ;
                    iWriter.print(prefix) ;
                    iWriter.print(": ") ;
                    iWriter.print(uri) ;
                    WriterLib.finish(iWriter) ;
                }
                iWriter.decIndent(len) ;
                WriterLib.finish(iWriter) ;

                iWriter.ensureStartOfLine() ;
                return true ;
            }
        }
        return false ;
    }
}