aswi2020horky-gitlab/project/Deserializer/src/CLI.java @ 88849adf

import java.io.File;
import java.io.IOException;
import java.util.HashMap;

import io.FileWorker;
import javafx.application.Application;

/**
 * Command-line user interface.
 */
public class CLI implements IConversionResults {

	/**
	 * Instances of this class define options for running the application.
	 */
	private static class Option {

		/**
		 * Abbreviation for the option name.
		 */
		String abbr;

		/**
		 * Text describing the activity for the option.
		 */
		String about;

		/**
		 * Converts an input argument to the option for comparison with options in the
		 * list.
		 * 
		 * @param abbr input argument.
		 */
		public Option(String abbr) {
			this.abbr = abbr;
			this.about = null;
		}

		/**
		 * Creates an option to the option list.
		 * 
		 * @param abbr  option abbreviation.
		 * @param about option description.
		 */
		public Option(String abbr, String about) {
			this.abbr = abbr;
			this.about = about;
		}

		@Override
		public String toString() {
			return abbr + "\t" + about;
		}

		@Override
		public int hashCode() {
			return abbr.hashCode();
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj) {
				return true;
			}
			if (obj == null) {
				return false;
			}
			if (this.getClass() != obj.getClass()) {
				return false;
			}
			Option other = (Option) obj;
			return this.abbr.equals(other.abbr);
		}
	}

	/**
	 * The list of options for running the application.
	 */
	private static HashMap<Option, Runnable> options;

	/**
	 * Whether the resulting JSON should be written to the command line.
	 */
	private static boolean printJSON;

	/**
	 * Where to save the resulting JSON.
	 */
	private static File outputFile;

	/**
	 * Initialization of static variables.
	 */
	static {
		options = new HashMap<Option, Runnable>();
		options.put(new Option("-?", "\tPrint this help message."), () -> {
			help();
		});
		options.put(new Option("-help", "Print this help message."), () -> {
			help();
		});
		options.put(new Option("-print", "Prints the resulting json to the console."), () -> {
			setPrintJSON();
		});
		printJSON = false;
	}

	/**
	 * Prints help for running the application.
	 */
	private static void help() {
		System.out.println("\n" + "Usage:" + "\n" + "    java ... -jar JOU_Deserializer.jar [-options] [args...]" + "\n"
				+ "\n" + "...:" + "\n"
				+ "    When running the app in the JVM 11, the following VM arguments may be required:" + "\n"
				+ "        --module-path libs\\javafx-sdk-11.0.2\\lib --add-modules=javafx.controls" + "\n" + "\n"
				+ "-options:" + "\n" + printOptions() + "\n" + "args...:" + "\n"
				+ "    Input and output file. Output file need not be specified, if options contains -print." + "\n"
				+ "\n" + "Note: if no options and arguments are specified, the GUI is created." + "\n" + "\n"
				+ "Example:" + "\n" + "    CLI: java -jar JOU_Deserializer.jar -print input.data output.json" + "\n"
				+ "    GUI: java -jar JOU_Deserializer.jar" + "\n");
	}

	/**
	 * Sets printJSON to true.
	 */
	private static void setPrintJSON() {
		printJSON = true;
	}

	/**
	 * @return string with all possible options for running the application.
	 */
	private static String printOptions() {
		String result = "";
		for (Option option : options.keySet()) {
			result += "    " + option + "\n";
		}
		return result;
	}

	/**
	 * Main method.
	 * 
	 * @param args input arguments.
	 */
	public static void main(String[] args) {
		if (args.length == 0) {
			// If no arguments exist, launch the GUI.
			Application.launch(Window.class, args);
		} else {
			// Command-line user interface only.
			String input = null, output = null;

			// Get options and input parameters.
			for (int i = 0; i < args.length; i++) {
				Option o = new Option(args[i]);
				if (options.containsKey(o)) {
					options.get(o).run();
				} else {
					input = args[i];
					if (i == args.length - 1) {
						// If we are at the end of the list, check printJSON.
						if (!printJSON) {
							errorMessage("output not defined");
							return;
						}
					} else {
						output = args[i + 1];
						break;
					}
				}
			}

			if (input == null) {
				// Only options.
				return;
			}

			// Set input and output file.
			File inputFile = new File(input);
			if (!inputFile.exists()) {
				errorMessage("the input file does not exist");
				return;
			}
			outputFile = output == null ? null : new File(output);

			// Create and run converter.
			Converter thread = new Converter(new CLI());
			thread.start();
			thread.setInput(inputFile, null);
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				errorMessage("interrupted sleep of the main thread");
			}
			thread.end();
			try {
				thread.join();
			} catch (InterruptedException e) {
				errorMessage("while waiting for the converter thread");
			}
		}
	}

	/**
	 * Prints an error message.
	 * 
	 * @param message error message.
	 */
	private static void errorMessage(String message) {
		System.out.println("\nERROR: " + message.toUpperCase() + "!\n");
	}

	@Override
	public void loadingInputFileError() {
		errorMessage("there was an error loading the file");
	}

	@Override
	public void completed(String json, String loaded) {
		if (json != null) {
			System.out.println("Deserialization completed.");
			saveJson(json);
		} else {
			errorMessage("an error occurred while deserializing");
			if (loaded != null) {
				System.out.println(
						"The following actions (print, save) will work with the extracted content of the file.");
				saveJson(loaded);
			} else {
				// This shouldn't happen, it's catched by the loadingInputFileError().
				System.out.println("The content read from the file is null.");
			}
		}
	}

	/**
	 * Saves the resulting text (JSON) to the file or prints it to the command line.
	 * 
	 * @param json the resulting text in JSON format.
	 */
	private void saveJson(String json) {
		if (outputFile != null) {
			try {
				FileWorker.saveJson(outputFile, json);
				System.out.println("The JSON file was saved correctly.");
			} catch (IOException e) {
				errorMessage("there was an error saving the JSON file.");
			}
		} else {
			// Options contain -print.
			System.out.println(json);
		}
	}

}