package org.apache.maven.toolchain.building;
   
   /*
    * 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.
   */
  
  import org.apache.maven.building.Problem;
  import org.apache.maven.building.ProblemCollector;
  import org.apache.maven.building.ProblemCollectorFactory;
  import org.apache.maven.building.Source;
  import org.apache.maven.toolchain.io.ToolchainsParseException;
  import org.apache.maven.toolchain.io.ToolchainsReader;
  import org.apache.maven.toolchain.io.ToolchainsWriter;
  import org.apache.maven.toolchain.merge.MavenToolchainMerger;
  import org.apache.maven.toolchain.model.PersistedToolchains;
  import org.apache.maven.toolchain.model.TrackableBase;
  import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
  import org.codehaus.plexus.interpolation.InterpolationException;
  import org.codehaus.plexus.interpolation.InterpolationPostProcessor;
  import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  import java.io.IOException;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  
  /**
   * 
   * @author Robert Scholte
   * @since 3.3.0
   */
  @Named
  @Singleton
  public class DefaultToolchainsBuilder
      implements ToolchainsBuilder
  {
      private MavenToolchainMerger toolchainsMerger = new MavenToolchainMerger();
  
      @Inject
      private ToolchainsWriter toolchainsWriter;
  
      @Inject
      private ToolchainsReader toolchainsReader;
  
      @Override
      public ToolchainsBuildingResult build( ToolchainsBuildingRequest request )
          throws ToolchainsBuildingException
      {
          ProblemCollector problems = ProblemCollectorFactory.newInstance( null );
          
          PersistedToolchains globalToolchains = readToolchains( request.getGlobalToolchainsSource(), request, problems );
  
          PersistedToolchains userToolchains = readToolchains( request.getUserToolchainsSource(), request, problems );
  
          toolchainsMerger.merge( userToolchains, globalToolchains, TrackableBase.GLOBAL_LEVEL );
          
          problems.setSource( "" );
  
          userToolchains = interpolate( userToolchains, problems );
  
          if ( hasErrors( problems.getProblems() ) )
          {
              throw new ToolchainsBuildingException( problems.getProblems() );
          }
  
  
          return new DefaultToolchainsBuildingResult( userToolchains, problems.getProblems() );
      }
  
      private PersistedToolchains interpolate( PersistedToolchains toolchains, ProblemCollector problems )
      {
  
          StringWriter stringWriter = new StringWriter( 1024 * 4 );
          try
          {
              toolchainsWriter.write( stringWriter, null, toolchains );
          }
          catch ( IOException e )
          {
             throw new IllegalStateException( "Failed to serialize toolchains to memory", e );
         }
 
         String serializedToolchains = stringWriter.toString();
 
         RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
 
         try
         {
             interpolator.addValueSource( new EnvarBasedValueSource() );
         }
         catch ( IOException e )
         {
             problems.add( Problem.Severity.WARNING, "Failed to use environment variables for interpolation: "
                     + e.getMessage(), -1, -1, e );
         }
 
         interpolator.addPostProcessor( new InterpolationPostProcessor()
         {
             @Override
             public Object execute( String expression, Object value )
             {
                 if ( value != null )
                 {
                     // we're going to parse this back in as XML so we need to escape XML markup
                     value = value.toString().replace( "&", "&amp;" ).replace( "<", "&lt;" ).replace( ">", "&gt;" );
                     return value;
                 }
                 return null;
             }
         } );
 
         try
         {
             serializedToolchains = interpolator.interpolate( serializedToolchains );
         }
         catch ( InterpolationException e )
         {
             problems.add( Problem.Severity.ERROR, "Failed to interpolate toolchains: " + e.getMessage(), -1, -1, e );
             return toolchains;
         }
 
         PersistedToolchains result;
         try
         {
             Map<String, ?> options = Collections.singletonMap( ToolchainsReader.IS_STRICT, Boolean.FALSE );
 
             result = toolchainsReader.read( new StringReader( serializedToolchains ), options );
         }
         catch ( IOException e )
         {
             problems.add( Problem.Severity.ERROR, "Failed to interpolate toolchains: " + e.getMessage(), -1, -1, e );
             return toolchains;
         }
 
         return result;
     }
 
     private PersistedToolchains readToolchains( Source toolchainsSource, ToolchainsBuildingRequest request,
                                                 ProblemCollector problems )
     {
         if ( toolchainsSource == null )
         {
             return new PersistedToolchains();
         }
 
         PersistedToolchains toolchains;
 
         try
         {
             Map<String, ?> options = Collections.singletonMap( ToolchainsReader.IS_STRICT, Boolean.TRUE );
 
             try
             {
                 toolchains = toolchainsReader.read( toolchainsSource.getInputStream(), options );
             }
             catch ( ToolchainsParseException e )
             {
                 options = Collections.singletonMap( ToolchainsReader.IS_STRICT, Boolean.FALSE );
 
                 toolchains = toolchainsReader.read( toolchainsSource.getInputStream(), options );
 
                 problems.add( Problem.Severity.WARNING, e.getMessage(), e.getLineNumber(), e.getColumnNumber(),
                               e );
             }
         }
         catch ( ToolchainsParseException e )
         {
             problems.add( Problem.Severity.FATAL, "Non-parseable toolchains " + toolchainsSource.getLocation()
                 + ": " + e.getMessage(), e.getLineNumber(), e.getColumnNumber(), e );
             return new PersistedToolchains();
         }
         catch ( IOException e )
         {
             problems.add( Problem.Severity.FATAL, "Non-readable toolchains " + toolchainsSource.getLocation()
                 + ": " + e.getMessage(), -1, -1, e );
             return new PersistedToolchains();
         }
 
         return toolchains;
     }
     
     private boolean hasErrors( List<Problem> problems )
     {
         if ( problems != null )
         {
             for ( Problem problem : problems )
             {
                 if ( Problem.Severity.ERROR.compareTo( problem.getSeverity() ) >= 0 )
                 {
                     return true;
                 }
             }
         }
 
         return false;
     }
 }