/** **********************************************************************
 *
 * Copyright 2018 Jochen Staerk
 *
 * Use is subject to license terms.
 *
 * Licensed 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.
 *
 *********************************************************************** */
package org.mustangproject.toecount;

/***
 * This is the command line interface to mustangproject
 *
 */

import com.sanityinc.jargs.CmdLineParser;
import com.sanityinc.jargs.CmdLineParser.Option;
import org.mustangproject.ZUGFeRD.*;

import javax.xml.transform.TransformerException;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.logging.Level;
import java.util.logging.Logger;

public class Toecount {
	// build with: /opt/local/bin/mvn clean compile assembly:single
	private static void printUsage() {
		System.err.println(getUsage());
	}

	private static String getUsage() {
		return "Usage: [-d,--directory] [-l,--listfromstdin] [-i,--ignorefileextension] | [-c,--combine] | [-e,--extract] | [-u,--upgrade] | [-a,--a3only] | [-h,--help] \r\n"
				+ "* Count operations\n" + "        -d, --directory count ZUGFeRD files in directory to be scanned\n"
				+ "                If it is a directory, it will recurse.\n"
				+ "        -l, --listfromstdin     count ZUGFeRD files from a list of linefeed separated files on runtime.\n"
				+ "                It will start once a blank line has been entered.\n" + "\n"
				+ "        Additional parameter for both count operations\n"
				+ "        [-i, --ignorefileextension]     Check for all files (*.*) instead of PDF files only (*.pdf)\n"
				+ "\n" + "* Merge operations\n" + "        -e, --extract   extract ZUGFeRD PDF to XML file\n"
				+ "                Additional parameters (optional - user will be prompted if not defined)\n"
				+ "                [--source <filename>]: set input PDF file\n"
				+ "                [--out <filename>]: set output XML file\n"
				+ "        -u, --upgrade   upgrade ZUGFeRD XML to ZUGFeRD 2 XML\n"
				+ "                Additional parameters (optional - user will be prompted if not defined)\n"
				+ "                [--source <filename>]: set input XML ZUGFeRD 1 file\n"
				+ "                [--out <filename>]: set output XML ZUGFeRD 2 file\n"
				+ "        -a, --a3only    upgrade from PDF/A1 to A3 only (no ZUGFeRD data attached)\n"
				+ "                Additional parameters (optional - user will be prompted if not defined)\n"
				+ "                [--source <filename>]: set input PDF file\n"
				+ "                [--out <filename>]: set output PDF file\n"
				+ "        -c, --combine   combine XML and PDF file to ZUGFeRD PDF file\n"
				+ "                Additional parameters (optional - user will be prompted if not defined)\n"
				+ "                [--source <filename>]: set input PDF file\n"
				+ "                [--source-xml <filename>]: set input XML file\n"
				+ "                [--out <filename>]: set output PDF file\n"
				+ "                [--format <fx|zf>]: set ZUGFeRD or FacturX\n"
				+ "                [--version <1|2>]: set ZUGFeRD version\n"
				+ "                [--profile <...>]: set ZUGFeRD profile\n"
				+ "                        For ZUGFeRD v1: <B>ASIC, <C>OMFORT or <E>XTENDED\n"
				+ "                        For ZUGFeRD v2: <M>INIMUM, BASIC <W>L, <B>ASIC, <C>IUS, <E>N16931, E<X>TENDED ";
	}

	private static void printHelp() {
		System.out.println("Mustangproject.org " + org.mustangproject.ZUGFeRD.Version.VERSION + " \r\n"
				+ "A Apache Public License library and command line tool for statistics on PDF invoices with\r\n"
				+ "ZUGFeRD Metadata (http://www.zugferd.org)\r\n" + "\r\n" + getUsage() + "\r\n"
				+ "* Count operations\r\n" + "\t-d, --directory\tcount ZUGFeRD files in directory to be scanned\r\n"
				+ "\t\tIf it is a directory, it will recurse.\r\n"
				+ "\t-l, --listfromstdin\tcount ZUGFeRD files from a list of linefeed separated files on runtime.\r\n"
				+ "\t\tIt will start once a blank line has been entered.\r\n" + "\r\n"
				+ "\tAdditional parameter for both count operations\r\n"
				+ "\t[-i, --ignorefileextension]\tCheck for all files (*.*) instead of PDF files only (*.pdf)\r\n"
				+ "\r\n" + "* Merge operations\r\n" + "\t-e, --extract\textract ZUGFeRD PDF to XML file\r\n"
				+ "\t\tAdditional parameters (optional - user will be prompted if not defined)\r\n"
				+ "\t\t[--source <filename>]: set input PDF file\r\n"
				+ "\t\t[--out <filename>]: set output XML file\r\n"
				+ "\t-u, --upgrade\tupgrade ZUGFeRD XML to ZUGFeRD 2 XML\r\n"
				+ "\t\tAdditional parameters (optional - user will be prompted if not defined)\r\n"
				+ "\t\t[--source <filename>]: set input XML ZUGFeRD 1 file\r\n"
				+ "\t\t[--out <filename>]: set output XML ZUGFeRD 2 file\r\n"
				+ "\t-a, --a3only\tupgrade from PDF/A1 to A3 only (no ZUGFeRD data attached) \r\n"
				+ "\t\tAdditional parameters (optional - user will be prompted if not defined)\r\n"
				+ "\t\t[--source <filename>]: set input PDF file\r\n"
				+ "\t\t[--out <filename>]: set output PDF file\r\n"
				+ "\t-c, --combine\tcombine XML and PDF file to ZUGFeRD PDF file\r\n"
				+ "\t\tAdditional parameters (optional - user will be prompted if not defined)\r\n"
				+ "\t\t[--source <filename>]: set input PDF file\r\n"
				+ "\t\t[--source-xml <filename>]: set input XML file\r\n"
				+ "\t\t[--out <filename>]: set output PDF file\r\n"
				+ "\t\t[--format <fx|zf>]: enable factur-x or ZUGFeRD\r\n"
				+ "\t\t[--version <1|2>]: set ZUGFeRD version\r\n"
				+ "\t\t[--profile <...>]: set ZUGFeRD profile\r\n"
				+ "\t\t\tFor ZUGFeRD v1: <B>ASIC, <C>OMFORT or <E>XTENDED\r\n"
				+ "\t\t\tFor ZUGFeRD v2: <M>INIMUM, BASIC <W>L, <B>ASIC, <C>IUS, <E>N16931, E<X>TENDED\r\n");
	}

	/**
	 * Asks the user (repeatedly, if neccessary) on the command line for a String
	 * (offering a defaultValue) conforming to a Regex pattern
	 *
	 * @param prompt       the question to be asked to the user
	 * @param defaultValue the default return value if user hits enter
	 * @param pattern      a regex of acceptable values
	 * @return the user answer conforming to pattern
	 * @throws Exception if pattern not compielable or IOexception on input
	 */
	protected static String getStringFromUser(String prompt, String defaultValue, String pattern) throws Exception {
		String input = "";
		if (!defaultValue.matches(pattern)) {
			throw new Exception("Default value must match pattern");
		}
		boolean firstInput = true;
		do {
			// for a more sophisticated dialogue maybe https://github.com/mabe02/lanterna/
			// could be taken into account
			System.out.print(prompt + " (default: " + defaultValue + ")");
			if (!firstInput) {
				System.out.print("\n(allowed pattern: " + pattern + ")");

			}
			System.out.print(":");
			BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
			try {
				input = buffer.readLine();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			if (input.isEmpty()) {
				// pressed return without entering anything
				input = defaultValue;
			}

			firstInput = false;
		} while (!input.matches(pattern));

		return input;
	}

	/**
	 * Prompts the user for a input or output filename
	 *
	 * @param the                 text the user is asked
	 * @param a                   default Filename
	 * @param expectedExtension   will warn if filename does not match expected file extension
	 * @param ensureFileExists    will warn if file does NOT exist (for input files)
	 * @param ensureFileNotExists will warn if file DOES exist (for output files)
	 * @return String
	 */
	protected static String getFilenameFromUser(String prompt, String defaultFilename, String expectedExtension,
												boolean ensureFileExists, boolean ensureFileNotExists) {
		boolean fileExistenceOK = false;
		String selectedName = "";
		do {
			// for a more sophisticated dialogue maybe https://github.com/mabe02/lanterna/
			// could be taken into account
			System.out.print(prompt + " (default: " + defaultFilename + "):");
			BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
			try {
				selectedName = buffer.readLine();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			if (selectedName.isEmpty()) {
				// pressed return without entering anything
				selectedName = defaultFilename;
			}

			// error cases
			if (!selectedName.toLowerCase().endsWith(expectedExtension.toLowerCase())) {
				System.err.println("Expected " + expectedExtension
						+ " extension, this may corrupt your file. Do you still want to continue?(Y|N)");
				String selectedAnswer = "";
				try {
					selectedAnswer = buffer.readLine();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				if (!selectedAnswer.equals("Y") && !selectedAnswer.equals("y")) {
					System.err.println("Aborted by user");
					System.exit(-1);
				}

			} else if (ensureFileExists) {
				if (fileExists(selectedName)) {
					fileExistenceOK = true;
				} else {
					System.out.println("File does not exist, try again or CTRL+C to cancel");
					// discard the input, a scanner.reset is not sufficient
					fileExistenceOK = false;
				}
			} else {
				fileExistenceOK = true;

				if (ensureFileNotExists) {
					if (fileExists(selectedName)) {
						fileExistenceOK = false;
						System.out.println("Output file already exists, try again or CTRL+C to cancel");
						// discard the input, a scanner.reset is not sufficient
					}
				} else {
					fileExistenceOK = true;
				}
			}

		} while (!fileExistenceOK);

		return selectedName;
	}

	// /opt/local/bin/mvn clean compile assembly:single
	public static void main(String[] args) {
		try {

			CmdLineParser parser = new CmdLineParser();

			// Option: Help
			Option<Boolean> helpOption = parser.addBooleanOption('h', "help");

			// Generic options available for multiple command
			// --source: input file
			Option<String> sourceOption = parser.addStringOption("source");
			// --out: output file
			Option<String> outOption = parser.addStringOption("out");

			// Command: Extract XML
			// --extract
			// (--source: input PDF file)
			// (--out: output XML file)
			Option<Boolean> extractOption = parser.addBooleanOption('e', "extract");

			// Command: Migrating ZUGFeRD 1 to 2
			// --upgrade
			// (--source: input XML ZUGFeRD 1 file)
			// (--out: output XML ZUGFeRD 2 file)
			Option<Boolean> upgradeOption = parser.addBooleanOption('u', "upgrade");

			// Command: Convert PDF/A-1 to PDF/A-3
			// --a3only
			// (--source: input PDF file)
			// (--out: output PDF file)
			Option<Boolean> a3onlyOption = parser.addBooleanOption('a', "a3only");

			// Command: Combining PDF and XML
			// --combine
			// (--source: input PDF file)
			// (--source-xml: input XML file)
			// (--out: output PDF file)
			// (--version: ZUGFeRD version)
			// (--profile: ZUGFeRD profile)
			Option<Boolean> combineOption = parser.addBooleanOption('c', "combine");
			Option<String> sourceXmlOption = parser.addStringOption("source-xml");
			Option<String> formatOption = parser.addStringOption('f', "format");
			Option<String> zugferdVersionOption = parser.addStringOption("version");
			Option<String> zugferdProfileOption = parser.addStringOption("profile");

			// Command: Show metrics in dir
			// --directory
			// (--ignorefileextension)
			Option<String> dirnameOption = parser.addStringOption('d', "directory");
			Option<Boolean> ignoreFileExtOption = parser.addBooleanOption('i', "ignorefileextension");

			// Command: Show metrics from list from stdin
			// --listfromstdin
			Option<Boolean> filesFromStdInOption = parser.addBooleanOption('l', "listfromstdin");

			try {
				parser.parse(args);
			} catch (CmdLineParser.OptionException e) {
				System.err.println(e.getMessage());
				printUsage();
				System.exit(2);
			}

			// Retrieve all options
			String directoryName = parser.getOptionValue(dirnameOption);
			Boolean filesFromStdIn = parser.getOptionValue(filesFromStdInOption, Boolean.FALSE);
			Boolean combineRequested = parser.getOptionValue(combineOption, Boolean.FALSE);
			Boolean extractRequested = parser.getOptionValue(extractOption, Boolean.FALSE);
			Boolean helpRequested = parser.getOptionValue(helpOption, Boolean.FALSE);
			Boolean upgradeRequested = parser.getOptionValue(upgradeOption, Boolean.FALSE);
			Boolean ignoreFileExt = parser.getOptionValue(ignoreFileExtOption, Boolean.FALSE);
			Boolean a3only = parser.getOptionValue(a3onlyOption, Boolean.FALSE);
			String sourceName = parser.getOptionValue(sourceOption);
			String sourceXMLName = parser.getOptionValue(sourceXmlOption);
			String outName = parser.getOptionValue(outOption);
			String format = parser.getOptionValue(formatOption);
			String zugferdVersion = parser.getOptionValue(zugferdVersionOption);
			String zugferdProfile = parser.getOptionValue(zugferdProfileOption);

			if (helpRequested) {
				printHelp();
			} else if (((directoryName != null) && (directoryName.length() > 0)) || filesFromStdIn.booleanValue()) {
				performMetrics(directoryName, filesFromStdIn, ignoreFileExt);
			} else if (combineRequested) {
				performCombine(sourceName, sourceXMLName, outName, format, zugferdVersion, zugferdProfile);
			} else if (extractRequested) {
				performExtract(sourceName, outName);
			} else if (a3only) {
				performConvert(sourceName, outName);
			} else if (upgradeRequested) {
				performUpgrade(sourceName, outName);
			} else {
				// no argument or argument unknown
				printUsage();
				System.exit(2);
			}
		} catch (Exception e) {
			e.printStackTrace();
			Logger.getLogger(Toecount.class.getName()).log(Level.SEVERE, null, e);
			System.exit(-1);
		}

	}

	private static void performUpgrade(String xmlName, String outName) throws IOException, TransformerException {

		// Get params from user if not already defined
		if (xmlName == null) {
			xmlName = getFilenameFromUser("ZUGFeRD 1.0 XML source", "ZUGFeRD-invoice.xml", "xml", true, false);
		} else {
			System.out.println("ZUGFeRD 1.0 XML source set to " + xmlName);
		}
		if (outName == null) {
			outName = getFilenameFromUser("ZUGFeRD 2.0 XML target", "factur-x.xml", "xml", false, true);
		} else {
			System.out.println("ZUGFeRD 1.0 XML source set to " + outName);
		}

		// Verify params
		ensureFileExists(xmlName);
		ensureFileNotExists(outName);

		// All params are good! continue...
		ZUGFeRDMigrator zmi = new ZUGFeRDMigrator();
		String xml = null;
		xml = zmi.migrateFromV1ToV2(xmlName);
		Files.write(Paths.get(outName), xml.getBytes());
		System.out.println("Written to " + outName);
		/*
		 * } catch (FileNotFoundException ex) {
		 * Logger.getLogger(Toecount.class.getName()).log(Level.SEVERE, null, ex);
		 */
	}

	private static void performConvert(String pdfName, String outName) throws IOException {
		/*
		 * ZUGFeRDExporter ze= new ZUGFeRDExporterFromA1Factory()
		 * .setProducer("toecount") .setCreator(System.getProperty("user.name"))
		 * .loadFromPDFA1("invoice.pdf");
		 */
		// Get params from user if not already defined
		if (pdfName == null) {
			pdfName = getFilenameFromUser("Source PDF", "invoice.pdf", "pdf", true, false);
		} else {
			System.out.println("Source PDF set to " + pdfName);
		}
		if (outName == null) {
			outName = getFilenameFromUser("Target PDF", "invoice.a3.pdf", "pdf", false, true);
		} else {
			System.out.println("Target PDF set to " + outName);
		}

		// Verify params
		ensureFileExists(pdfName);
		ensureFileNotExists(outName);

		// All params are good! continue...
		ZUGFeRDExporter ze = new ZUGFeRDExporterFromA1Factory().setAttachZUGFeRDHeaders(false).load(pdfName);

		ze.export(outName);
		System.out.println("Written to " + outName);
	}

	private static void performExtract(String pdfName, String xmlName) throws IOException {
		// Get params from user if not already defined
		if (pdfName == null) {
			pdfName = getFilenameFromUser("Source PDF", "invoice.pdf", "pdf", true, false);
		} else {
			System.out.println("Source PDF set to " + pdfName);
		}
		if (xmlName == null) {
			xmlName = getFilenameFromUser("ZUGFeRD XML", "ZUGFeRD-invoice.xml", "xml", false, true);
		} else {
			System.out.println("ZUGFeRD XML set to " + pdfName);
		}

		// Verify params
		ensureFileExists(pdfName);
		ensureFileNotExists(xmlName);

		// All params are good! continue...
		ZUGFeRDImporter zi = new ZUGFeRDImporter(pdfName);
		byte[] XMLContent = zi.getRawXML();
		if (XMLContent == null) {
			System.err.println("No ZUGFeRD XML found in PDF file");

		} else {
			Files.write(Paths.get(xmlName), XMLContent);
			System.out.println("Written to " + xmlName);
		}
	}

	private static void performCombine(String pdfName, String xmlName, String outName, String format, String zfVersion,
									   String zfProfile) throws Exception {
		/*
		 * ZUGFeRDExporter ze= new ZUGFeRDExporterFromA1Factory()
		 * .setProducer("toecount") .setCreator(System.getProperty("user.name"))
		 * .loadFromPDFA1("invoice.pdf");
		 */
		try {
			int zfIntVersion = ZUGFeRDExporter.DefaultZUGFeRDVersion;
			ZUGFeRDConformanceLevel zfConformanceLevelProfile = ZUGFeRDConformanceLevel.EXTENDED;

			if (pdfName == null) {
				pdfName = getFilenameFromUser("Source PDF", "invoice.pdf", "pdf", true, false);
			} else {
				System.out.println("Source PDF set to " + pdfName);
			}

			if (xmlName == null) {
				xmlName = getFilenameFromUser("ZUGFeRD XML", "ZUGFeRD-invoice.xml", "xml", true, false);
			} else {
				System.out.println("ZUGFeRD XML set to " + xmlName);
			}

			if (outName == null) {
				outName = getFilenameFromUser("Ouput PDF", "invoice.ZUGFeRD.pdf", "pdf", false, true);
			} else {
				System.out.println("Ouput PDF set to " + outName);
			}

			if (format == null) {
				try {
					format = getStringFromUser("Format (fx=Factur-X, zf=ZUGFeRD,)", "zf", "fx|zf");
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			} else {
				System.out.println("Format set to " + format);
			}


			if (zfVersion == null) {
				try {
					zfVersion = getStringFromUser("Version (1 or 2)", "1", "1|2");
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			} else {
				System.out.println("Version set to " + zfVersion);
			}
			zfIntVersion = Integer.valueOf(zfVersion);

			if (zfProfile == null) {
				try {
					if (format.equals("zf")&&(zfIntVersion == 1)) {
						zfProfile = getStringFromUser("Profile b)asic, c)omfort or e)xtended", "e",
								"B|b|C|c|E|e");
					} else {
						zfProfile = getStringFromUser(
								"Profile  [M]INIMUM, BASIC [W]L, [B]ASIC,\n" + "[C]IUS, [E]N16931, E[X]TENDED",
								"E", "M|m|W|w|B|b|C|c|E|e|X|x|");
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			} else {
				System.out.println("Profile set to " + zfProfile);
			}
			zfProfile = zfProfile.toLowerCase();

			// Verify params
			ensureFileExists(pdfName);
			ensureFileExists(xmlName);
			ensureFileNotExists(outName);
			
			if ((format.equals("fx"))&&(zfIntVersion>1)) {
				throw new Exception("Factur-X is only available in version 1 (roughly corresponding to ZF2)");
			}

			if ((format.equals("zf"))&&(zfIntVersion == 1)) {
				if (zfProfile.equals("b")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.BASIC;
				} else if (zfProfile.equals("c")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.COMFORT;
				} else if (zfProfile.equals("e")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.EXTENDED;
				} else {
					throw new Exception(String.format("Unknown ZUGFeRD profile '%s'", zfProfile));
				}
			} else if (((format.equals("zf"))&&(zfIntVersion == 2))||(format.equals("fx"))) {
				if (zfProfile.equals("m")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.MINIMUM;
				} else if (zfProfile.equals("w")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.BASICWL;
				} else if (zfProfile.equals("b")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.BASIC;
				} else if (zfProfile.equals("c")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.CIUS;
				} else if (zfProfile.equals("e")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.EN16931;
				} else if (zfProfile.equals("x")) {
					zfConformanceLevelProfile = ZUGFeRDConformanceLevel.EXTENDED;
				} else {
					throw new Exception(String.format("Unknown ZUGFeRD profile '%s'", zfProfile));
				}
			} else {
				throw new Exception(String.format("Unknown version '%i'", zfIntVersion));
			}

			// All params are good! continue...
			ZUGFeRDExporter ze = new ZUGFeRDExporterFromA1Factory().setProducer("Toecount")
					.setCreator(System.getProperty("user.name")).setZUGFeRDConformanceLevel(zfConformanceLevelProfile)
					.load(pdfName);

			ze.setZUGFeRDVersion(zfIntVersion);
			if (format.equals("fx")) {
				ze.setFacturX();
			}
		

			ze.setZUGFeRDXMLData(Files.readAllBytes(Paths.get(xmlName)));

			ze.export(outName);

			System.out.println("Written to " + outName);

		} catch (IOException e) {
			e.printStackTrace();
			// } catch (JAXBException e) {
			// e.printStackTrace();
		}
	}

	private static void performMetrics(String directoryName, Boolean filesFromStdIn, Boolean ignoreFileExt)
			throws IOException {

		StatRun sr = new StatRun();
		if (ignoreFileExt) {
			sr.ignoreFileExtension();
		}
		if (directoryName != null) {
			Path startingDir = Paths.get(directoryName);

			if (Files.isRegularFile(startingDir)) {
				String filename = startingDir.toString();
				FileChecker fc = new FileChecker(filename, sr);

				fc.checkForZUGFeRD();
				System.out.print(fc.getOutputLine());

			} else if (Files.isDirectory(startingDir)) {
				FileTraverser pf = new FileTraverser(sr);
				Files.walkFileTree(startingDir, pf);
			}
		}

		if (filesFromStdIn) {
			BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
			String s;
			while ((s = in.readLine()) != null && s.length() != 0) {
				FileChecker fc = new FileChecker(s, sr);

				fc.checkForZUGFeRD();
				System.out.print(fc.getOutputLine());

			}

		}
		System.out.println(sr.getSummaryLine());
	}

	private static void ensureFileExists(String fileName) throws IOException {
		if (!fileExists(fileName)) {
			throw new IOException(String.format("File %s does not exists", fileName));
		}
	}

	private static void ensureFileNotExists(String fileName) throws IOException {
		if (fileExists(fileName)) {
			throw new IOException(String.format("File %s does not exists", fileName));
		}
	}

	private static Boolean fileExists(String fileName) {
		if (fileName == null)
			return false;
		File f = new File(fileName);
		return f.exists();
	}

}