/*
 * 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.felix.bundleplugin;


import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import aQute.bnd.service.AnalyzerPlugin;
import aQute.lib.osgi.Analyzer;
import aQute.lib.osgi.Jar;
import aQute.lib.osgi.Processor;
import aQute.lib.osgi.Resource;
import aQute.libg.generics.Create;
import aQute.libg.qtokens.QuotedTokenizer;
import aQute.libg.reporter.Reporter;


public class BlueprintPlugin implements AnalyzerPlugin
{

    static Pattern QN = Pattern.compile( "[_A-Za-z$][_A-Za-z0-9$]*(\\.[_A-Za-z$][_A-Za-z0-9$]*)*" );
    static Pattern PATHS = Pattern.compile( ".*\\.xml" );

    Transformer transformer;


    public BlueprintPlugin() throws Exception
    {
        transformer = getTransformer( getClass().getResource( "blueprint.xsl" ) );
    }


    public boolean analyzeJar( Analyzer analyzer ) throws Exception
    {
        transformer.setParameter( "nsh_interface",
            analyzer.getProperty( "nsh_interface" ) != null ? analyzer.getProperty( "nsh_interface" ) : "" );
        transformer.setParameter( "nsh_namespace",
            analyzer.getProperty( "nsh_namespace" ) != null ? analyzer.getProperty( "nsh_namespace" ) : "" );

        Set<String> headers = Create.set();

        String bpHeader = analyzer.getProperty( "Bundle-Blueprint", "OSGI-INF/blueprint" );
        Map<String, Map<String, String>> map = Processor.parseHeader( bpHeader, null );
        for ( String root : map.keySet() )
        {
            Jar jar = analyzer.getJar();
            Map<String, Resource> dir = jar.getDirectories().get( root );
            if ( dir == null || dir.isEmpty() )
            {
                Resource resource = jar.getResource( root );
                if ( resource != null )
                    process( analyzer, root, resource, headers );
                return false;
            }
            for ( Map.Entry<String, Resource> entry : dir.entrySet() )
            {
                String path = entry.getKey();
                Resource resource = entry.getValue();
                if ( PATHS.matcher( path ).matches() )
                    process( analyzer, path, resource, headers );
            }

        }

        // Group and analyze
        Map<String, Set<Attribute>> hdrs = Create.map();
        for ( String str : headers )
        {
            int idx = str.indexOf( ':' );
            if ( idx < 0 )
            {
                analyzer.warning( ( new StringBuilder( "Error analyzing services in blueprint resource: " ) ).append(
                    str ).toString() );
                continue;
            }
            String h = str.substring( 0, idx ).trim();
            String v = str.substring( idx + 1 ).trim();
            Set<Attribute> att = hdrs.get( h );
            if ( att == null )
            {
                att = new TreeSet<Attribute>();
                hdrs.put( h, att );
            }
            att.addAll( parseHeader( v, null ) );
        }
        // Merge
        for ( String header : hdrs.keySet() )
        {
            if ( "Import-Class".equals( header ) || "Import-Package".equals( header ) )
            {
                Set<Attribute> newAttr = hdrs.get( header );
                for ( Attribute a : newAttr )
                {
                    String pkg = a.getName();
                    if ( "Import-Class".equals( header ) )
                    {
                        int n = a.getName().lastIndexOf( '.' );
                        if ( n > 0 )
                        {
                            pkg = pkg.subSequence( 0, n ).toString();
                        }
                        else
                        {
                            continue;
                        }
                    }
                    if ( !analyzer.getReferred().containsKey( pkg ) )
                    {
                        analyzer.getReferred().put( pkg, a.getProperties() );
                    }
                }
            }
            else
            {
                Set<Attribute> orgAttr = parseHeader( analyzer.getProperty( header ), null );
                Set<Attribute> newAttr = hdrs.get( header );
                for ( Iterator<Attribute> it = newAttr.iterator(); it.hasNext(); )
                {
                    Attribute a = it.next();
                    for ( Attribute b : orgAttr )
                    {
                        if ( b.getName().equals( a.getName() ) )
                        {
                            it.remove();
                            break;
                        }
                    }
                }
                orgAttr.addAll( newAttr );
                // Rebuild from orgAttr
                StringBuilder sb = new StringBuilder();
                for ( Attribute a : orgAttr )
                {
                    if ( sb.length() > 0 )
                    {
                        sb.append( "," );
                    }
                    sb.append( a.getName() );
                    for ( Map.Entry<String, String> prop : a.getProperties().entrySet() )
                    {
                        sb.append( ';' ).append( prop.getKey() ).append( "=" );
                        if ( prop.getValue().matches( "[0-9a-zA-Z_-]+" ) )
                        {
                            sb.append( prop.getValue() );
                        }
                        else
                        {
                            sb.append( "\"" );
                            sb.append( prop.getValue().replace( "\"", "\\\"" ) );
                            sb.append( "\"" );
                        }
                    }
                }
                analyzer.setProperty( header, sb.toString() );
            }
        }
        return false;
    }


    private void process( Analyzer analyzer, String path, Resource resource, Set<String> headers )
    {
        InputStream in = null;
        try
        {
            in = resource.openInputStream();

            // Retrieve headers
            Set<String> set = analyze( in );
            headers.addAll( set );
        }
        catch ( Exception e )
        {
            analyzer.error( ( new StringBuilder( "Unexpected exception in processing spring resources(" ) )
                .append( path ).append( "): " ).append( e ).toString() );
        }
        finally
        {
            try
            {
                if ( in != null )
                {
                    in.close();
                }
            }
            catch ( IOException e )
            {
            }
        }
    }


    public Set<String> analyze( InputStream in ) throws Exception
    {
        Set<String> refers = new HashSet<String>();
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        javax.xml.transform.Result r = new StreamResult( bout );
        javax.xml.transform.Source s = new StreamSource( in );
        transformer.transform( s, r );
        ByteArrayInputStream bin = new ByteArrayInputStream( bout.toByteArray() );
        bout.close();
        BufferedReader br = new BufferedReader( new InputStreamReader( bin ) );
        for ( String line = br.readLine(); line != null; line = br.readLine() )
        {
            line = line.trim();
            line = line.replace( ";availability:=mandatory", "" );
            if ( line.length() > 0 )
            {
                refers.add( line );
            }
        }

        br.close();
        return refers;
    }


    protected Transformer getTransformer( URL url ) throws Exception
    {
        TransformerFactory tf = TransformerFactory.newInstance();
        javax.xml.transform.Source source = new StreamSource( url.openStream() );
        return tf.newTransformer( source );
    }

    public static class Attribute implements Comparable<Attribute>
    {
        private final String name;
        private final Map<String, String> properties;


        public Attribute( String name, Map<String, String> properties )
        {
            this.name = name;
            this.properties = properties;
        }


        public String getName()
        {
            return name;
        }


        public Map<String, String> getProperties()
        {
            return properties;
        }


        public int compareTo( Attribute a )
        {
            int c = name.compareTo( a.name );
            if ( c == 0 )
            {
                c = properties.equals( a.properties ) ? 0 : properties.size() < a.properties.size() ? -1 : properties
                    .hashCode() < a.properties.hashCode() ? -1 : +1;
            }
            return c;
        }


        @Override
        public boolean equals( Object o )
        {
            if ( this == o )
                return true;
            if ( o == null || getClass() != o.getClass() )
                return false;

            Attribute attribute = ( Attribute ) o;

            if ( name != null ? !name.equals( attribute.name ) : attribute.name != null )
                return false;
            if ( properties != null ? !properties.equals( attribute.properties ) : attribute.properties != null )
                return false;

            return true;
        }


        @Override
        public int hashCode()
        {
            int result = name != null ? name.hashCode() : 0;
            result = 31 * result + ( properties != null ? properties.hashCode() : 0 );
            return result;
        }
    }


    public static Set<Attribute> parseHeader( String value, Reporter logger )
    {
        if ( ( value == null ) || ( value.trim().length() == 0 ) )
        {
            return new TreeSet<Attribute>();
        }
        Set<Attribute> result = new TreeSet<Attribute>();
        QuotedTokenizer qt = new QuotedTokenizer( value, ";=," );
        char del = '\0';
        do
        {
            boolean hadAttribute = false;
            Map<String, String> clause = Create.map();
            List<String> aliases = Create.list();
            String name = qt.nextToken( ",;" );

            del = qt.getSeparator();
            if ( ( name == null ) || ( name.length() == 0 ) )
            {
                if ( ( logger != null ) && ( logger.isPedantic() ) )
                {
                    logger
                        .warning( "Empty clause, usually caused by repeating a comma without any name field or by having "
                            + "spaces after the backslash of a property file: " + value );
                }

                if ( name != null )
                    continue;
                break;
            }
            name = name.trim();

            aliases.add( name );
            String advalue;
            while ( del == ';' )
            {
                String adname = qt.nextToken();
                if ( ( del = qt.getSeparator() ) != '=' )
                {
                    if ( ( hadAttribute ) && ( logger != null ) )
                    {
                        logger.error( "Header contains name field after attribute or directive: " + adname + " from "
                            + value + ". Name fields must be consecutive, separated by a ';' like a;b;c;x=3;y=4" );
                    }

                    if ( ( adname != null ) && ( adname.length() > 0 ) )
                        aliases.add( adname.trim() );
                }
                else
                {
                    advalue = qt.nextToken();
                    if ( ( clause.containsKey( adname ) ) && ( logger != null ) && ( logger.isPedantic() ) )
                    {
                        logger.warning( "Duplicate attribute/directive name " + adname + " in " + value
                            + ". This attribute/directive will be ignored" );
                    }

                    if ( advalue == null )
                    {
                        if ( logger != null )
                        {
                            logger.error( "No value after '=' sign for attribute " + adname );
                        }
                        advalue = "";
                    }
                    clause.put( adname.trim(), advalue.trim() );
                    del = qt.getSeparator();
                    hadAttribute = true;
                }
            }

            for ( String clauseName : aliases )
            {
                result.add( new Attribute( clauseName, clause ) );
            }
        }
        while ( del == ',' );
        return result;
    }

}
