package afryca.consensusmodel.command;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;

import javax.inject.Inject;
import javax.inject.Named;

import org.apache.commons.io.IOUtils;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.e4.core.di.annotations.Execute;
import org.eclipse.e4.core.services.log.ILoggerProvider;
import org.eclipse.e4.core.services.log.Logger;
import org.eclipse.e4.core.services.nls.Translation;

import afryca.consensusmodel.Configuration;
import afryca.consensusmodel.l10n.Messages;

/**
 * Command for open consensus model configuration
 * 
 * @author Sinbad²
 * @version 3.0
 */
@SuppressWarnings("restriction")
public class OpenConfiguration {

	public static final String ID = "afryca.consensusmodel.command.open_configuration"; //$NON-NLS-1$

	public static final String FILE_PARAMETER = "file"; //$NON-NLS-1$

	private Logger logger;

	@Inject
	@Translation
	Messages messages;

	@Inject
	public void instantiateLogger(ILoggerProvider loggerProvider) {
		logger = loggerProvider.getClassLogger(this.getClass());
	}

	@Execute
	public Configuration execute(@Named(FILE_PARAMETER) String file) throws Exception {
		logger.info(messages.command_executed, ID);
		return readConfiguration(file);
	}

	private Configuration readConfiguration(String file) throws ExecutionException {
		Configuration configuration = null;
		if (file != null) {
			InputStream inputStream = null;
			try {
				if (isValidFile(file)) {
					inputStream = new FileInputStream(file);
				} else if (isValidURL(file)) {
					inputStream = new URL(file).openStream();
				} else {
					throw new ExecutionException(messages.wrong_file);
				}
				configuration = Configuration.parseConfiguration(IOUtils.toString(inputStream, "UTF-8")); //$NON-NLS-1$
				configuration.setFile(file);
				inputStream.close();
			} catch (IOException es) {
				if (inputStream != null) {
					try {
						inputStream.close();
					} catch (Exception e) {
					}
				}
				throw new ExecutionException(messages.wrong_file);
			}
		}
		return configuration;
	}

	private static boolean isValidFile(String fileName) {
		File file = new File(fileName);
		return (file.exists() && file.canRead());
	}

	private static boolean isValidURL(String url) {
		URL u = null;

		try {
			u = new URL(url);
		} catch (MalformedURLException e) {
			return false;
		}

		try {
			u.toURI();
		} catch (URISyntaxException e) {
			return false;
		}

		return true;
	}
}