/*******************************************************************************
 * Copyright (c) 2017, 2020 Obeo.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.acceleo.aql.launcher;

import java.io.PrintStream;

import org.eclipse.emf.common.util.BasicMonitor;
import org.eclipse.emf.common.util.Diagnostic;

/**
 * Command line interface utilities.
 * 
 * @author <a href="mailto:cedric.brun@obeo.fr">Cedric Brun</a>
 */
public final class CLIUtils {

	/**
	 * Resets the ANSI modifications.
	 */
	public static final String RESET = "\u001B[0m";

	/**
	 * Sets the ANSI color to black.
	 */
	public static final String BLACK = "\u001B[30;40;1m";

	/**
	 * Sets the ANSI color to red.
	 */
	public static final String RED = "\u001B[31;40;1m";

	/**
	 * Sets the ANSI color to green.
	 */
	public static final String GREEN = "\u001B[32;40;1m";

	/**
	 * Sets the ANSI color to yellow.
	 */
	public static final String YELLOW = "\u001B[33;40;1m";

	/**
	 * Sets the ANSI color to blue.
	 */
	public static final String BLUE = "\u001B[34;40;1m";

	/**
	 * Sets the ANSI color to purple.
	 */
	public static final String PURPLE = "\u001B[35;40;1m";

	/**
	 * Sets the ANSI color to cyan.
	 */
	public static final String CYAN = "\u001B[36;40;1m";

	/**
	 * Sets the ANSI color to white.
	 */
	public static final String WHITE = "\u001B[37;40;1m";

	/**
	 * The {@link CLIDecorator}.
	 */
	private static CLIDecorator decorator;

	/**
	 * Constructor.
	 */
	private CLIUtils() {
		// nothing to do here
	}

	/**
	 * Gets the {@link CLIDecorator} accroding to the current terminal.
	 * 
	 * @return the {@link CLIDecorator}
	 */
	public static CLIDecorator getDecorator() {
		if (decorator == null) {
			String colorTerm = System.getenv().get("COLORTERM");
			String term = System.getenv().get("TERM");
			if (colorTerm != null || (term != null && term.contains("color"))) {
				decorator = new CLIDecorator();
			} else {
				decorator = new NoDecoration();
			}
		}
		return decorator;
	}

	/**
	 * A {@link CLIDecorator} for color terminal.
	 * 
	 * @author <a href="mailto:cedric.brun@obeo.fr">Cedric Brun</a>
	 */
	public static class CLIDecorator {

		/**
		 * Gets the red ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the red ANSI string of the given text
		 */
		public String red(String txt) {
			return RED + txt + RESET;
		}

		/**
		 * Gets the black ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the black ANSI string of the given text
		 */
		public String black(String txt) {
			return BLACK + txt + RESET;
		}

		/**
		 * Gets the green ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the green ANSI string of the given text
		 */
		public String green(String txt) {
			return GREEN + txt + RESET;
		}

		/**
		 * Gets the yellow ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the yellow ANSI string of the given text
		 */
		public String yellow(String txt) {
			return YELLOW + txt + RESET;
		}

		/**
		 * Gets the blue ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the blue ANSI string of the given text
		 */
		public String blue(String txt) {
			return BLUE + txt + RESET;
		}

		/**
		 * Gets the purple ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the purple ANSI string of the given text
		 */
		public String purple(String txt) {
			return PURPLE + txt + RESET;
		}

		/**
		 * Gets the cyan ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the cyan ANSI string of the given text
		 */
		public String cyan(String txt) {
			return CYAN + txt + RESET;
		}

		/**
		 * Gets the white ANSI string of the given text.
		 * 
		 * @param txt
		 *            the text
		 * @return the white ANSI string of the given text
		 */
		public String white(String txt) {
			return WHITE + txt + RESET;
		}
	}

	/**
	 * A {@link CLIDecorator} for non color terminal.
	 * 
	 * @author <a href="mailto:cedric.brun@obeo.fr">Cedric Brun</a>
	 */
	public static class NoDecoration extends CLIDecorator {

		@Override
		public String red(String txt) {
			return txt;
		}

		@Override
		public String black(String txt) {
			return txt;
		}

		@Override
		public String green(String txt) {
			return txt;
		}

		@Override
		public String yellow(String txt) {
			return txt;
		}

		@Override
		public String blue(String txt) {
			return txt;
		}

		@Override
		public String purple(String txt) {
			return txt;
		}

		@Override
		public String cyan(String txt) {
			return txt;
		}

		@Override
		public String white(String txt) {
			return txt;
		}
	}

	/**
	 * A simple monitor that prints progress to a print stream.
	 */
	public static class ColoredPrinting extends BasicMonitor {

		/**
		 * The {@link PrintStream}.
		 */
		protected PrintStream printStream;

		/**
		 * Constructor.
		 * 
		 * @param printStream
		 *            the {@link PrintStream}
		 */
		public ColoredPrinting(PrintStream printStream) {
			this.printStream = printStream;
		}

		@Override
		public void beginTask(String name, int totalWork) {
			if (name != null && name.length() != 0) {
				printStream.println(getDecorator().blue(">>> " + name));
			}
		}

		@Override
		public void setTaskName(String name) {
			if (name != null && name.length() != 0) {
				printStream.println("<>> " + name);
			}
		}

		@Override
		public void subTask(String name) {
			if (name != null && name.length() != 0) {
				printStream.println(getDecorator().cyan("  > " + name));
			}
		}

		@Override
		public void setBlocked(Diagnostic reason) {
			super.setBlocked(reason);
			printStream.println(getDecorator().red("#>  " + reason.getMessage()));
		}

		@Override
		public void clearBlocked() {
			printStream.println(getDecorator().green("=>  " + getBlockedReason().getMessage()));
			super.clearBlocked();
		}
	}

}