package org.apache.maven.plugin.compiler;

/*
 * 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 java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.compiler.module.ModuleInfoParser;
import org.apache.maven.plugins.annotations.Component;
import org.apache.maven.plugins.annotations.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.plugins.annotations.ResolutionScope;
import org.codehaus.plexus.compiler.util.scan.SimpleSourceInclusionScanner;
import org.codehaus.plexus.compiler.util.scan.SourceInclusionScanner;
import org.codehaus.plexus.compiler.util.scan.StaleSourceScanner;

/**
 * Compiles application test sources.
 *
 * @author <a href="mailto:jason@maven.org">Jason van Zyl</a>
 * @version $Id$
 * @since 2.0
 */
@Mojo( name = "testCompile", defaultPhase = LifecyclePhase.TEST_COMPILE, threadSafe = true,
                requiresDependencyResolution = ResolutionScope.TEST )
public class TestCompilerMojo
    extends AbstractCompilerMojo
{
    protected static final String PS = System.getProperty( "path.separator" );
    
    /**
     * Set this to 'true' to bypass compilation of test sources.
     * Its use is NOT RECOMMENDED, but quite convenient on occasion.
     */
    @Parameter ( property = "maven.test.skip" )
    private boolean skip;

    /**
     * The source directories containing the test-source to be compiled.
     */
    @Parameter ( defaultValue = "${project.testCompileSourceRoots}", readonly = true, required = true )
    private List<String> compileSourceRoots;

    /**
     * The directory where compiled test classes go.
     */
    @Parameter ( defaultValue = "${project.build.testOutputDirectory}", required = true, readonly = true )
    private File outputDirectory;

    /**
     * A list of inclusion filters for the compiler.
     */
    @Parameter
    private Set<String> testIncludes = new HashSet<String>();

    /**
     * A list of exclusion filters for the compiler.
     */
    @Parameter
    private Set<String> testExcludes = new HashSet<String>();

    /**
     * The -source argument for the test Java compiler.
     *
     * @since 2.1
     */
    @Parameter ( property = "maven.compiler.testSource" )
    private String testSource;

    /**
     * The -target argument for the test Java compiler.
     *
     * @since 2.1
     */
    @Parameter ( property = "maven.compiler.testTarget" )
    private String testTarget;

    /**
     * the -release argument for the test Java compiler
     * 
     * @since 3.6
     */
    @Parameter ( property = "maven.compiler.testRelease" )
    private String testRelease;

    /**
     * <p>
     * Sets the arguments to be passed to test compiler (prepending a dash) if fork is set to true.
     * </p>
     * <p>
     * This is because the list of valid arguments passed to a Java compiler
     * varies based on the compiler version.
     * </p>
     *
     * @since 2.1
     */
    @Parameter
    private Map<String, String> testCompilerArguments;

    /**
     * <p>
     * Sets the unformatted argument string to be passed to test compiler if fork is set to true.
     * </p>
     * <p>
     * This is because the list of valid arguments passed to a Java compiler
     * varies based on the compiler version.
     * </p>
     *
     * @since 2.1
     */
    @Parameter
    private String testCompilerArgument;

    /**
     * <p>
     * Specify where to place generated source files created by annotation processing.
     * Only applies to JDK 1.6+
     * </p>
     *
     * @since 2.2
     */
    @Parameter ( defaultValue = "${project.build.directory}/generated-test-sources/test-annotations" )
    private File generatedTestSourcesDirectory;

    @Parameter( defaultValue = "${project.compileClasspathElements}", readonly = true )
    private List<String> compilePath;

    @Parameter( defaultValue = "${project.testClasspathElements}", readonly = true )
    private List<String> testPath;
    
    @Component
    private Map<String, ModuleInfoParser> moduleInfoParsers;

    private List<String> classpathElements;

    private List<String> modulepathElements;

    public void execute()
        throws MojoExecutionException, CompilationFailureException
    {
        if ( skip )
        {
            getLog().info( "Not compiling test sources" );
            return;
        }
        super.execute();
    }

    protected List<String> getCompileSourceRoots()
    {
        return compileSourceRoots;
    }

    protected List<String> getClasspathElements()
    {
        return classpathElements;
    }
    
    @Override
    protected List<String> getModulepathElements()
    {
        return modulepathElements;
    }

    protected File getOutputDirectory()
    {
        return outputDirectory;
    }

    @Override
    protected void preparePaths( Set<File> sourceFiles )
    {
        File mainOutputDirectory = new File( getProject().getBuild().getOutputDirectory() );

        boolean hasMainModuleDescriptor = new File( mainOutputDirectory, "module-info.class" ).exists();
        
        boolean hasTestModuleDescriptor = false;
        
        // Go through the source files to respect includes/excludes 
        for ( File sourceFile : sourceFiles )
        {
            // @todo verify if it is the root of a sourcedirectory?
            if ( "module-info.java".equals( sourceFile.getName() ) ) 
            {
                hasTestModuleDescriptor = true;
                break;
            }
        }
        
        List<String> testScopedElements = new ArrayList<String>( testPath );
        testScopedElements.removeAll( compilePath );
        
        if ( release != null )
        {
            if ( Integer.valueOf( release ) < 9 )
            {
                modulepathElements = Collections.emptyList();
                classpathElements = testPath;
                return;
            }
        }
        else if ( Double.valueOf( getTarget() ) < Double.valueOf( MODULE_INFO_TARGET ) )
        {
            modulepathElements = Collections.emptyList();
            classpathElements = testPath;
            return;
        }
            
        if ( hasTestModuleDescriptor )
        {
            modulepathElements = testPath;
            classpathElements = Collections.emptyList();

            if ( hasMainModuleDescriptor )
            {
                // maybe some extra analysis required
            }
            else
            {
                // very odd
                // Means that main sources must be compiled with -modulesource and -Xmodule:<moduleName>
                // However, this has a huge impact since you can't simply use it as a classpathEntry 
                // due to extra folder in between
                throw new UnsupportedOperationException( "Can't compile test sources "
                    + "when main sources are missing a module descriptor" );
            }
        }
        else
        {
            if ( hasMainModuleDescriptor )
            {
                modulepathElements = compilePath;
                classpathElements = testScopedElements;
                if ( compilerArgs == null )
                {
                    compilerArgs = new ArrayList<String>();
                }
                
                String moduleName = getModuleName( mainOutputDirectory );
                
                compilerArgs.add( "--patch-module" );
                
                StringBuilder addReadsValue = new StringBuilder( moduleName )
                                .append( '=' )
                                .append( mainOutputDirectory )
                                .append( PS );
                for ( String root : compileSourceRoots )
                {
                    addReadsValue.append( root ).append( PS );
                }
                
                compilerArgs.add( addReadsValue.toString() );
                
                compilerArgs.add( "--add-reads" );
                compilerArgs.add( moduleName + "=ALL-UNNAMED" );
            }
            else
            {
                modulepathElements = Collections.emptyList();
                classpathElements = testPath;
            }
        }
    }

    private String getModuleName( File mainOutputDirectory )
    {
        String moduleName = null;
        
        Map<String, Exception> exceptionMap = new LinkedHashMap<String, Exception>( moduleInfoParsers.size() ); 
        
        List<String> parserKeys = Arrays.asList( "reflect", "asm" );
        
        // The class format is still changing, for that reason provide multiple strategies to parse module-info 
        for ( String parserKey: parserKeys )
        {
            ModuleInfoParser parser = moduleInfoParsers.get( parserKey );

            try
            {
                moduleName = parser.getModuleDescriptor( mainOutputDirectory  ).name();
                
                if ( moduleName != null )
                {
                    break;
                }
            }
            catch ( Exception e )
            {
                exceptionMap.put( parserKey, e );
            }
        }
        
        if ( moduleName == null )
        {
            getLog().error( "Failed to parse module-info:" );
            
            for ( Map.Entry<String, Exception> exception : exceptionMap.entrySet() )
            {
                getLog().error( "With " + exception.getKey() + ": " + exception.getValue().getMessage() );
            }
            
            throw new RuntimeException( "Failed to parse module-info" );
        }
        return moduleName;
    }

    protected SourceInclusionScanner getSourceInclusionScanner( int staleMillis )
    {
        SourceInclusionScanner scanner;

        if ( testIncludes.isEmpty() && testExcludes.isEmpty() )
        {
            scanner = new StaleSourceScanner( staleMillis );
        }
        else
        {
            if ( testIncludes.isEmpty() )
            {
                testIncludes.add( "**/*.java" );
            }
            scanner = new StaleSourceScanner( staleMillis, testIncludes, testExcludes );
        }

        return scanner;
    }

    protected SourceInclusionScanner getSourceInclusionScanner( String inputFileEnding )
    {
        SourceInclusionScanner scanner;

        // it's not defined if we get the ending with or without the dot '.'
        String defaultIncludePattern = "**/*" + ( inputFileEnding.startsWith( "." ) ? "" : "." ) + inputFileEnding;

        if ( testIncludes.isEmpty() && testExcludes.isEmpty() )
        {
            testIncludes = Collections.singleton( defaultIncludePattern );
            scanner = new SimpleSourceInclusionScanner( testIncludes, Collections.<String>emptySet() );
        }
        else
        {
            if ( testIncludes.isEmpty() )
            {
                testIncludes.add( defaultIncludePattern );
            }
            scanner = new SimpleSourceInclusionScanner( testIncludes, testExcludes );
        }

        return scanner;
    }

    protected String getSource()
    {
        return testSource == null ? source : testSource;
    }

    protected String getTarget()
    {
        return testTarget == null ? target : testTarget;
    }
    
    @Override
    protected String getRelease()
    {
        return testRelease == null ? release : testRelease;
    }

    protected String getCompilerArgument()
    {
        return testCompilerArgument == null ? compilerArgument : testCompilerArgument;
    }

    protected Map<String, String> getCompilerArguments()
    {
        return testCompilerArguments == null ? compilerArguments : testCompilerArguments;
    }

    protected File getGeneratedSourcesDirectory()
    {
        return generatedTestSourcesDirectory;
    }

    @Override
    protected boolean isTestCompile()
    {
        return true;
    }

}