/*
 * Copyright (C) 2010, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.transport;

import java.util.Arrays;

import org.eclipse.jgit.internal.JGitText;

A credential requested from a CredentialsProvider. Most users should work with the specialized subclasses: 

Username for usernames
Password for passwords
StringType for other general string information
CharArrayType for other general secret information

This class is not thread-safe. Applications should construct their own
instance for each use, as the value is held within the CredentialItem object.
/**
 * A credential requested from a
 * {@link org.eclipse.jgit.transport.CredentialsProvider}.
 *
 * Most users should work with the specialized subclasses:
 * <ul>
 * <li>{@link org.eclipse.jgit.transport.CredentialItem.Username} for
 * usernames</li>
 * <li>{@link org.eclipse.jgit.transport.CredentialItem.Password} for
 * passwords</li>
 * <li>{@link org.eclipse.jgit.transport.CredentialItem.StringType} for other
 * general string information</li>
 * <li>{@link org.eclipse.jgit.transport.CredentialItem.CharArrayType} for other
 * general secret information</li>
 * </ul>
 *
 * This class is not thread-safe. Applications should construct their own
 * instance for each use, as the value is held within the CredentialItem object.
 */
public abstract class CredentialItem {
	private final String promptText;

	private final boolean valueSecure;

	
Initialize a prompt.
Params:
promptText – 
           prompt to display to the user alongside of the input field.
           Should be sufficient text to indicate what to supply for this
           item.
maskValue – 
           true if the value should be masked from displaying during
           input. This should be true for passwords and other secrets,
           false for names and other public data./**
	 * Initialize a prompt.
	 *
	 * @param promptText
	 *            prompt to display to the user alongside of the input field.
	 *            Should be sufficient text to indicate what to supply for this
	 *            item.
	 * @param maskValue
	 *            true if the value should be masked from displaying during
	 *            input. This should be true for passwords and other secrets,
	 *            false for names and other public data.
	 */
	public CredentialItem(String promptText, boolean maskValue) {
		this.promptText = promptText;
		this.valueSecure = maskValue;
	}

	
Get prompt to display to the user.
Returns:
prompt to display to the user./**
	 * Get prompt to display to the user.
	 *
	 * @return prompt to display to the user.
	 */
	public String getPromptText() {
		return promptText;
	}

	
Whether the value should be masked when entered.
Returns:
true if the value should be masked when entered./**
	 * Whether the value should be masked when entered.
	 *
	 * @return true if the value should be masked when entered.
	 */
	public boolean isValueSecure() {
		return valueSecure;
	}

	
Clear the stored value, destroying it as much as possible.
/**
	 * Clear the stored value, destroying it as much as possible.
	 */
	public abstract void clear();

	
An item whose value is stored as a string. When working with secret data, consider CharArrayType instead, as the internal members of the array can be cleared, reducing the chances that the password is left in memory after authentication is completed. /**
	 * An item whose value is stored as a string.
	 *
	 * When working with secret data, consider {@link CharArrayType} instead, as
	 * the internal members of the array can be cleared, reducing the chances
	 * that the password is left in memory after authentication is completed.
	 */
	public static class StringType extends CredentialItem {
		private String value;

		
Initialize a prompt for a single string.
Params:
promptText – 
           prompt to display to the user alongside of the input
           field. Should be sufficient text to indicate what to
           supply for this item.
maskValue – 
           true if the value should be masked from displaying during
           input. This should be true for passwords and other
           secrets, false for names and other public data./**
		 * Initialize a prompt for a single string.
		 *
		 * @param promptText
		 *            prompt to display to the user alongside of the input
		 *            field. Should be sufficient text to indicate what to
		 *            supply for this item.
		 * @param maskValue
		 *            true if the value should be masked from displaying during
		 *            input. This should be true for passwords and other
		 *            secrets, false for names and other public data.
		 */
		public StringType(String promptText, boolean maskValue) {
			super(promptText, maskValue);
		}

		@Override
		public void clear() {
			value = null;
		}

		
Returns:
the current value/** @return the current value */
		public String getValue() {
			return value;
		}

		
Params:
newValue – /**
		 *
		 * @param newValue
		 */
		public void setValue(String newValue) {
			value = newValue;
		}
	}

	
An item whose value is stored as a char[] and is therefore clearable. /** An item whose value is stored as a char[] and is therefore clearable. */
	public static class CharArrayType extends CredentialItem {
		private char[] value;

		
Initialize a prompt for a secure value stored in a character array.
Params:
promptText – 
           prompt to display to the user alongside of the input
           field. Should be sufficient text to indicate what to
           supply for this item.
maskValue – 
           true if the value should be masked from displaying during
           input. This should be true for passwords and other
           secrets, false for names and other public data./**
		 * Initialize a prompt for a secure value stored in a character array.
		 *
		 * @param promptText
		 *            prompt to display to the user alongside of the input
		 *            field. Should be sufficient text to indicate what to
		 *            supply for this item.
		 * @param maskValue
		 *            true if the value should be masked from displaying during
		 *            input. This should be true for passwords and other
		 *            secrets, false for names and other public data.
		 */
		public CharArrayType(String promptText, boolean maskValue) {
			super(promptText, maskValue);
		}

		
Destroys the current value, clearing the internal array. /** Destroys the current value, clearing the internal array. */
		@Override
		public void clear() {
			if (value != null) {
				Arrays.fill(value, (char) 0);
				value = null;
			}
		}

		
Get the current value. The returned array will be cleared out when clear() is called. Callers that need the array elements to survive should delay invoking clear() until the value is no longer necessary. 
Returns:
the current value array. The actual internal array is
        returned, reducing the number of copies present in memory./**
		 * Get the current value.
		 *
		 * The returned array will be cleared out when {@link #clear()} is
		 * called. Callers that need the array elements to survive should delay
		 * invoking {@code clear()} until the value is no longer necessary.
		 *
		 * @return the current value array. The actual internal array is
		 *         returned, reducing the number of copies present in memory.
		 */
		public char[] getValue() {
			return value;
		}

		
Set the new value, clearing the old value array.
Params:
newValue – 
           if not null, the array is copied./**
		 * Set the new value, clearing the old value array.
		 *
		 * @param newValue
		 *            if not null, the array is copied.
		 */
		public void setValue(char[] newValue) {
			clear();

			if (newValue != null) {
				value = new char[newValue.length];
				System.arraycopy(newValue, 0, value, 0, newValue.length);
			}
		}

		
Set the new value, clearing the old value array.
Params:
newValue – 
           the new internal array. The array is NOT copied./**
		 * Set the new value, clearing the old value array.
		 *
		 * @param newValue
		 *            the new internal array. The array is <b>NOT</b> copied.
		 */
		public void setValueNoCopy(char[] newValue) {
			clear();
			value = newValue;
		}
	}

	
An item whose value is a boolean choice, presented as Yes/No. /** An item whose value is a boolean choice, presented as Yes/No. */
	public static class YesNoType extends CredentialItem {
		private boolean value;

		
Initialize a prompt for a single boolean answer.
Params:
promptText – 
           prompt to display to the user alongside of the input
           field. Should be sufficient text to indicate what to
           supply for this item./**
		 * Initialize a prompt for a single boolean answer.
		 *
		 * @param promptText
		 *            prompt to display to the user alongside of the input
		 *            field. Should be sufficient text to indicate what to
		 *            supply for this item.
		 */
		public YesNoType(String promptText) {
			super(promptText, false);
		}

		@Override
		public void clear() {
			value = false;
		}

		
Returns:
the current value/** @return the current value */
		public boolean getValue() {
			return value;
		}

		
Set the new value.
Params:
newValue – /**
		 * Set the new value.
		 *
		 * @param newValue
		 */
		public void setValue(boolean newValue) {
			value = newValue;
		}
	}

	
An advice message presented to the user, with no response required. /** An advice message presented to the user, with no response required. */
	public static class InformationalMessage extends CredentialItem {
		
Initialize an informational message.
Params:
messageText – 
           message to display to the user./**
		 * Initialize an informational message.
		 *
		 * @param messageText
		 *            message to display to the user.
		 */
		public InformationalMessage(String messageText) {
			super(messageText, false);
		}

		@Override
		public void clear() {
			// Nothing to clear.
		}
	}

	
Prompt for a username, which is not masked on input. /** Prompt for a username, which is not masked on input. */
	public static class Username extends StringType {
		
Initialize a new username item, with a default username prompt. /** Initialize a new username item, with a default username prompt. */
		public Username() {
			super(JGitText.get().credentialUsername, false);
		}
	}

	
Prompt for a password, which is masked on input. /** Prompt for a password, which is masked on input. */
	public static class Password extends CharArrayType {
		
Initialize a new password item, with a default password prompt. /** Initialize a new password item, with a default password prompt. */
		public Password() {
			super(JGitText.get().credentialPassword, true);
		}

		
Initialize a new password item, with given prompt.
Params:
msg – 
           prompt message/**
		 * Initialize a new password item, with given prompt.
		 *
		 * @param msg
		 *            prompt message
		 */
		public Password(String msg) {
			super(msg, true);
		}
	}
}