package de.retest.recheck.ignore;

import java.io.IOException;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.HashSet;
import java.util.Set;

import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import de.retest.recheck.ui.descriptors.Element;
import de.retest.recheck.ui.diff.AttributeDifference;

public class JSShouldIgnoreImpl implements ShouldIgnore {

	private static final Logger logger = LoggerFactory.getLogger( JSShouldIgnoreImpl.class );

	private static final String JS_ENGINE_NAME = "JavaScript";

	private final ScriptEngine engine;
	private final Set<String> unknownFunctions = new HashSet<>();

	public JSShouldIgnoreImpl( final Path ignoreFilePath ) {
		final ScriptEngineManager manager = new ScriptEngineManager();
		engine = manager.getEngineByName( JS_ENGINE_NAME );
		try {
			engine.eval( readScriptFile( ignoreFilePath ) );
		} catch ( final ScriptException e ) {
			throw new IllegalArgumentException( e );
		}
	}

	Reader readScriptFile( final Path ignoreFilePath ) {
		try {
			logger.info( "Reading JS ignore rules file from {}.", ignoreFilePath );
			return Files.newBufferedReader( ignoreFilePath, StandardCharsets.UTF_8 );
		} catch ( final IOException e ) {
			throw new IllegalArgumentException( e );
		}
	}

	@Override
	public boolean shouldIgnoreElement( final Element element ) {
		return callBooleanJSFunction( "shouldIgnoreElement", element );
	}

	@Override
	public boolean shouldIgnoreAttributeDifference( final Element element,
			final AttributeDifference attributeDifference ) {
		return callBooleanJSFunction( "shouldIgnoreAttributeDifference", element, attributeDifference );
	}

	private boolean callBooleanJSFunction( final String functionName, final Object... args ) {
		if ( unknownFunctions.contains( functionName ) ) {
			return false;
		}
		final Invocable inv = (Invocable) engine;
		// call function from script file
		try {
			final Object callResult = inv.invokeFunction( functionName, args );
			if ( callResult == null ) {
				logger.warn( "{} returned 'null' instead of a boolean value. Interpreting that as 'false'.",
						functionName );
				return false;
			}
			if ( !(callResult instanceof Boolean) ) {
				throw new ClassCastException( "'" + callResult + "' of type " + callResult.getClass()
						+ " cannot be cast to java.lang.Boolean." );
			}
			return (boolean) callResult;
		} catch ( final ScriptException e ) {
			throw new IllegalArgumentException( "JS `" + functionName + "` method caused an exception: ", e );
		} catch ( final NoSuchMethodException e ) {
			logger.warn( "Specified JS ignore file has no '{}' function.", functionName );
			unknownFunctions.add( functionName );
		}
		return false;
	}
}

@@ -1090,38 +1090,32 @@
 %7D catch ( final 
-Script
 Exception e ) %7B%0A
@@ -1121,43 +1121,84 @@
 %0A%09%09%09
-throw new IllegalArgumentException(
+logger.error( %22Reading script file '%7B%7D' caused exception: %22, ignoreFilePath,
  e )
@@ -2443,103 +2443,33 @@
 %09%09%09%09
-throw new ClassCastException( %22'%22 + callResult + %22' of type %22 + callResult.getClass()%0A%09%09%09%09%09%09+ %22
+logger.error( %22'%7B%7D' of %7B%7D
  can
@@ -2502,16 +2502,51 @@
 oolean.%22
+, callResult, callResult.getClass()
  );%0A%09%09%09%7D
@@ -2625,70 +2625,30 @@
 %0A%09%09%09
-throw new IllegalArgumentException( %22JS %60%22 + functionName + %22%60
+logger.error( %22JS '%7B%7D'
  met
@@ -2672,20 +2672,49 @@
 eption: 
+%7B%7D
 %22, 
-e
+functionName, e.getMessage()
  );%0A%09%09%7D 

Update error logging