/*
 * #%L
 * SciJava Common shared library for SciJava software.
 * %%
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 * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
 * Institute of Molecular Cell Biology and Genetics.
 * %%
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 * 
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 *    this list of conditions and the following disclaimer.
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 *    this list of conditions and the following disclaimer in the documentation
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package org.scijava.script;

import java.util.List;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;

import org.scijava.plugin.PluginInfo;

/**
 * Abstract superclass for {@link ScriptLanguage} implementations which adapt an
 * existing {@link ScriptEngineFactory}.
 * <p>
 * This is useful for situations where a JSR-223-compliant script engine has
 * been provided, but whose behavior we need to extend or tweak.
 * </p>
 * 
 * @author Curtis Rueden
 */
public class AdaptedScriptLanguage extends AbstractScriptLanguage {

	/** The {@link ScriptEngineFactory} which this one adapts. */
	private final ScriptEngineFactory base;

	/**
	 * Creates a new {@link AdaptedScriptLanguage} wrapping the given
	 * {@link ScriptEngineFactory}.
	 */
	public AdaptedScriptLanguage(final ScriptEngineFactory base) {
		if (base == null) {
			throw new NullPointerException();
		}
		this.base = base;
	}

	/**
	 * Creates a new {@link AdaptedScriptLanguage} wrapping the
	 * {@link ScriptEngineFactory} with the given name.
	 */
	public AdaptedScriptLanguage(final String factoryName) {
		this(findFactory(factoryName));
	}

	// -- ScriptEngineFactory methods --

	@Override
	public String getEngineName() {
		return base.getEngineName();
	}

	@Override
	public String getEngineVersion() {
		return base.getEngineVersion();
	}

	@Override
	public List<String> getExtensions() {
		return base.getExtensions();
	}

	@Override
	public List<String> getMimeTypes() {
		return base.getMimeTypes();
	}

	@Override
	public List<String> getNames() {
		return base.getNames();
	}

	@Override
	public String getLanguageName() {
		final PluginInfo<?> info = getInfo();
		final String name = info == null ? null : info.getName();
		return name != null && !name.isEmpty() ? name : base.getLanguageName();
	}

	@Override
	public String getLanguageVersion() {
		return base.getLanguageVersion();
	}

	@Override
	public Object getParameter(final String key) {
		return base.getParameter(key);
	}

	@Override
	public String getMethodCallSyntax(final String obj, final String m,
		final String... args)
	{
		return base.getMethodCallSyntax(obj, m, args);
	}

	@Override
	public String getOutputStatement(final String toDisplay) {
		return base.getOutputStatement(toDisplay);
	}

	@Override
	public String getProgram(final String... statements) {
		return base.getProgram(statements);
	}

	@Override
	public ScriptEngine getScriptEngine() {
		return base.getScriptEngine();
	}

	// -- Helper methods --

	private static ScriptEngineFactory findFactory(final String factoryName) {
		final ScriptEngineManager manager = new ScriptEngineManager();
		for (final ScriptEngineFactory factory : manager.getEngineFactories()) {
			for (final String name : factory.getNames()) {
				if (factoryName.equals(name)) return factory;
			}
		}
		throw new IllegalArgumentException("No such script engine: " + factoryName);
	}

}
