package org.apache.maven.shared.filtering;

import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.util.*;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;
import org.apache.maven.settings.Settings;
import org.apache.maven.shared.utils.StringUtils;
import org.apache.maven.shared.utils.io.FileUtils;
import org.codehaus.plexus.interpolation.*;
import org.codehaus.plexus.interpolation.multi.MultiDelimiterStringSearchInterpolator;
import org.codehaus.plexus.logging.AbstractLogEnabled;

import javax.annotation.Nonnull;

class BaseFilter extends AbstractLogEnabled implements DefaultFilterInfo {


	/**
	 * @see org.apache.maven.shared.filtering.MavenFileFilter#getDefaultFilterWrappers(org.apache.maven.project.MavenProject, java.util.List, boolean, org.apache.maven.execution.MavenSession)
	 * @deprecated
	 */
	public List<FileUtils.FilterWrapper> getDefaultFilterWrappers( final MavenProject mavenProject,
			List<String> filters,
			final boolean escapedBackslashesInFilePath,
			MavenSession mavenSession )
			throws MavenFilteringException
	{
		return getDefaultFilterWrappers( mavenProject, filters, escapedBackslashesInFilePath, mavenSession, null );
	}


	@Nonnull public List<FileUtils.FilterWrapper> getDefaultFilterWrappers( final MavenProject mavenProject, List<String> filters,
			final boolean escapedBackslashesInFilePath,
			MavenSession mavenSession,
			MavenResourcesExecution mavenResourcesExecution )
			throws MavenFilteringException
	{

		MavenResourcesExecution mre =
				mavenResourcesExecution == null ? new MavenResourcesExecution() : mavenResourcesExecution.copyOf();

		mre.setMavenProject( mavenProject );
		mre.setMavenSession( mavenSession );
		mre.setFilters( filters );
		mre.setEscapedBackslashesInFilePath( escapedBackslashesInFilePath );

		return getDefaultFilterWrappers( mre );

	}

	@Nonnull public List<FileUtils.FilterWrapper> getDefaultFilterWrappers( final AbstractMavenFilteringRequest req )
			throws MavenFilteringException
	{
		// backup values
		boolean supportMultiLineFiltering = req.isSupportMultiLineFiltering();

		// compensate for null parameter value.
		final AbstractMavenFilteringRequest request = req == null ? new MavenFileFilterRequest() : req;

		request.setSupportMultiLineFiltering( supportMultiLineFiltering );

		// Here we build some properties which will be used to read some properties files
		// to interpolate the expression ${ } in this properties file

		// Take a copy of filterProperties to ensure that evaluated filterTokens are not propagated
		// to subsequent filter files. Note: this replicates current behaviour and seems to make sense.

		final Properties baseProps = new Properties();

		// Project properties
		if ( request.getMavenProject() != null )
		{
			baseProps.putAll( request.getMavenProject().getProperties() == null
					? Collections.emptyMap()
					: request.getMavenProject().getProperties() );
		}
		// TODO this is NPE free but do we consider this as normal
		// or do we have to throw an MavenFilteringException with mavenSession cannot be null
		if ( request.getMavenSession() != null )
		{
			// execution properties wins
			baseProps.putAll( request.getMavenSession().getExecutionProperties() );
		}

		// now we build properties to use for resources interpolation

		final Properties filterProperties = new Properties();

		File basedir = request.getMavenProject() != null ? request.getMavenProject().getBasedir() : new File( "." );

		loadProperties( filterProperties, basedir, request.getFileFilters(), baseProps );
		if ( filterProperties.size() < 1 )
		{
			filterProperties.putAll( baseProps );
		}

		if ( request.getMavenProject() != null )
		{
			if ( request.isInjectProjectBuildFilters() )
			{
				@SuppressWarnings( "unchecked" )
				List<String> buildFilters = new ArrayList<String>( request.getMavenProject().getBuild().getFilters() );

				// JDK-8015656: (coll) unexpected NPE from removeAll
				if ( request.getFileFilters() != null )
				{
					buildFilters.removeAll( request.getFileFilters() );
				}

				loadProperties( filterProperties, basedir, buildFilters, baseProps );
			}

			// Project properties
			filterProperties.putAll( request.getMavenProject().getProperties() == null
					? Collections.emptyMap()
					: request.getMavenProject().getProperties() );
		}
		if ( request.getMavenSession() != null )
		{
			// execution properties wins
			filterProperties.putAll( request.getMavenSession().getExecutionProperties() );
		}

		if ( request.getAdditionalProperties() != null )
		{
			// additional properties wins
			filterProperties.putAll( request.getAdditionalProperties() );
		}

		List<FileUtils.FilterWrapper> defaultFilterWrappers = request == null
				? new ArrayList<FileUtils.FilterWrapper>( 1 )
				: new ArrayList<FileUtils.FilterWrapper>( request.getDelimiters().size() + 1 );

		if ( getLogger().isDebugEnabled() )
		{
			getLogger().debug( "properties used " + filterProperties );
		}

		final ValueSource propertiesValueSource = new PropertiesBasedValueSource( filterProperties );

		if ( request != null )
		{
			FileUtils.FilterWrapper wrapper =
					new Wrapper( request.getDelimiters(), request.getMavenProject(), request.getMavenSession(),
							propertiesValueSource, request.getProjectStartExpressions(), request.getEscapeString(),
							request.isEscapeWindowsPaths(), request.isSupportMultiLineFiltering() );

			defaultFilterWrappers.add( wrapper );
		}

		return defaultFilterWrappers;
	}

	/**
	 * default visibility only for testing reason !
	 */
	void loadProperties( Properties filterProperties, File basedir, List<String> propertiesFilePaths, Properties baseProps )
			throws MavenFilteringException
	{
		if ( propertiesFilePaths != null )
		{
			Properties workProperties = new Properties();
			workProperties.putAll( baseProps );

			for ( String filterFile : propertiesFilePaths )
			{
				if ( StringUtils.isEmpty(filterFile) )
				{
					// skip empty file name
					continue;
				}
				try
				{
					File propFile = FileUtils.resolveFile( basedir, filterFile );
					Properties properties = PropertyUtils.loadPropertyFile( propFile, workProperties );
					filterProperties.putAll( properties );
					workProperties.putAll( properties );
				}
				catch ( IOException e )
				{
					throw new MavenFilteringException( "Error loading property file '" + filterFile + "'", e );
				}
			}
		}
	}

	private static final class Wrapper
			extends FileUtils.FilterWrapper
	{

		private LinkedHashSet<String> delimiters;

		private MavenProject project;

		private ValueSource propertiesValueSource;

		private List<String> projectStartExpressions;

		private String escapeString;

		private boolean escapeWindowsPaths;

		private final MavenSession mavenSession;

		private boolean supportMultiLineFiltering;

		Wrapper( LinkedHashSet<String> delimiters, MavenProject project, MavenSession mavenSession,
				ValueSource propertiesValueSource, List<String> projectStartExpressions, String escapeString,
				boolean escapeWindowsPaths, boolean supportMultiLineFiltering )
		{
			super();
			this.delimiters = delimiters;
			this.project = project;
			this.mavenSession = mavenSession;
			this.propertiesValueSource = propertiesValueSource;
			this.projectStartExpressions = projectStartExpressions;
			this.escapeString = escapeString;
			this.escapeWindowsPaths = escapeWindowsPaths;
			this.supportMultiLineFiltering = supportMultiLineFiltering;
		}

		public Reader getReader( Reader reader )
		{
			MultiDelimiterStringSearchInterpolator interpolator = new MultiDelimiterStringSearchInterpolator();
			interpolator.setDelimiterSpecs( delimiters );

			RecursionInterceptor ri = null;
			if ( projectStartExpressions != null && !projectStartExpressions.isEmpty() )
			{
				ri = new PrefixAwareRecursionInterceptor( projectStartExpressions, true );
			}
			else
			{
				ri = new SimpleRecursionInterceptor();
			}

			interpolator.addValueSource( propertiesValueSource );

			if ( project != null )
			{
				interpolator.addValueSource( new PrefixedObjectValueSource( projectStartExpressions, project, true ) );
			}

			if ( mavenSession != null )
			{
				interpolator.addValueSource( new PrefixedObjectValueSource( "session", mavenSession ) );

				final Settings settings = mavenSession.getSettings();
				if ( settings != null )
				{
					interpolator.addValueSource( new PrefixedObjectValueSource( "settings", settings ) );
					interpolator.addValueSource(
							new SingleResponseValueSource( "localRepository", settings.getLocalRepository() ) );
				}
			}

			interpolator.setEscapeString( escapeString );

			if ( escapeWindowsPaths )
			{
				interpolator.addPostProcessor( new InterpolationPostProcessor()
				{
					public Object execute( String expression, Object value )
					{
						if ( value instanceof String )
						{
							return FilteringUtils.escapeWindowsPath( (String) value );
						}

						return value;
					}
				} );
			}

			MultiDelimiterInterpolatorFilterReaderLineEnding filterReader =
					new MultiDelimiterInterpolatorFilterReaderLineEnding( reader, interpolator, supportMultiLineFiltering );
			filterReader.setRecursionInterceptor( ri );
			filterReader.setDelimiterSpecs( delimiters );

			filterReader.setInterpolateWithPrefixPattern( false );
			filterReader.setEscapeString( escapeString );

			return filterReader;
		}

	}
}