package org.apache.maven.plugin.testing.resources;

/*
 * 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.io.IOException;
import java.util.Collection;
import java.util.Set;
import java.util.TreeSet;

import org.codehaus.plexus.util.DirectoryScanner;
import org.codehaus.plexus.util.FileUtils;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.rules.TestWatcher;
import org.junit.runner.Description;

/**
 * Junit4 test {@link Rule} to extract and assert test resources.
 * 
 * @since 3.1.0
 */
public class TestResources
    extends TestWatcher
{

    private final String projectsDir;

    private final String workDir;

    public TestResources()
    {
        this( "src/test/projects", "target/test-projects" );
    }

    public TestResources( String projectsDir, String workDir )
    {
        this.projectsDir = projectsDir;
        this.workDir = workDir;
    }

    private String name;

    @Override
    protected void starting( Description d )
    {
        String methodName = d.getMethodName();
        if ( methodName != null )
        {
            methodName = methodName.replace( '/', '_' ).replace( '\\', '_' );
        }
        name = d.getTestClass().getSimpleName() + "_" + methodName;
    }

    /**
     * Creates new clean copy of test project directory structure. The copy is named after both the test being executed
     * and test project name, which allows the same test project can be used by multiple tests and by different
     * instances of the same parametrized tests.<br/>
     * TODO Provide alternative working directory naming for Windows, which still limits path names to ~250 charecters
     */
    public File getBasedir( String project )
        throws IOException
    {
        if ( name == null )
        {
            throw new IllegalStateException( getClass().getSimpleName()
                + " must be a test class field annotated with org.junit.Rule" );
        }
        File src = new File( projectsDir, project ).getCanonicalFile();
        Assert.assertTrue( "Test project directory does not exist: " + src.getPath(), src.isDirectory() );
        File basedir = new File( workDir, name + "_" + project ).getCanonicalFile();
        FileUtils.deleteDirectory( basedir );
        Assert.assertTrue( "Test project working directory created", basedir.mkdirs() );
        FileUtils.copyDirectoryStructure( src, basedir );
        return basedir;
    }

    // static helpers

    public static void cp( File basedir, String from, String to )
        throws IOException
    {
        // TODO ensure destination lastModified timestamp changes
        FileUtils.copyFile( new File( basedir, from ), new File( basedir, to ) );
    }

    public static void assertFileContents( File basedir, String expectedPath, String actualPath )
        throws IOException
    {
        String expected = FileUtils.fileRead( new File( basedir, expectedPath ) );
        String actual = FileUtils.fileRead( new File( basedir, actualPath ) );
        Assert.assertEquals( expected, actual );
    }

    public static void assertDirectoryContents( File dir, String... expectedPaths )
    {
        DirectoryScanner scanner = new DirectoryScanner();
        scanner.setBasedir( dir );
        scanner.addDefaultExcludes();
        scanner.scan();

        Set<String> actual = new TreeSet<String>();
        for ( String path : scanner.getIncludedFiles() )
        {
            actual.add( path );
        }
        for ( String path : scanner.getIncludedDirectories() )
        {
            if ( path.length() > 0 )
            {
                actual.add( path + "/" );
            }
        }

        Set<String> expected = new TreeSet<String>();
        if ( expectedPaths != null )
        {
            for ( String path : expectedPaths )
            {
                expected.add( path );
            }
        }

        // compare textual representation to make diff easier to understand
        Assert.assertEquals( toString( expected ), toString( actual ) );
    }

    private static String toString( Collection<String> strings )
    {
        StringBuilder sb = new StringBuilder();
        for ( String string : strings )
        {
            sb.append( string ).append( '\n' );
        }
        return sb.toString();
    }

    public static void touch( File basedir, String path )
        throws InterruptedException
    {
        touch( new File( basedir, path ) );
    }

    public static void touch( File file )
        throws InterruptedException
    {
        if ( !file.isFile() )
        {
            throw new IllegalArgumentException( "Not a file " + file );
        }
        long lastModified = file.lastModified();
        file.setLastModified( System.currentTimeMillis() );

        // TODO do modern filesystems still have this silly lastModified resolution?
        if ( lastModified == file.lastModified() )
        {
            Thread.sleep( 1000L );
            file.setLastModified( System.currentTimeMillis() );
        }
    }

    public static void rm( File basedir, String path )
    {
        Assert.assertTrue( "delete " + path, new File( basedir, path ).delete() );
    }

    /**
     * @since 3.2.0
     */
    public static void create( File basedir, String... paths )
        throws IOException
    {
        if ( paths == null || paths.length == 0 )
        {
            throw new IllegalArgumentException();
        }
        for ( String path : paths )
        {
            File file = new File( basedir, path );
            Assert.assertTrue( file.getParentFile().mkdirs() );
            file.createNewFile();
            Assert.assertTrue( file.isFile() && file.canRead() );
        }
    }

}