/**
 *    PermissionPair.java
 *    Copyright (C) 2010 New Zealand Digital Library, http://expeditee.org
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.expeditee.items;

import org.expeditee.settings.UserSettings;

public class PermissionPair {

	private UserAppliedPermission ownerPermission;
	private UserAppliedPermission notOwnerPermission;

	public PermissionPair(String permissionCode, UserAppliedPermission defaultPermission) {
		ownerPermission = defaultPermission;
		notOwnerPermission = defaultPermission;

		if (permissionCode != null) {

			permissionCode = permissionCode.trim().toLowerCase();
			if (permissionCode.length() != 0) {

				if (permissionCode.length() == 1 || (permissionCode.length() == 2 && permissionCode.startsWith("-"))) {
					// replicate it to cover ifOwner/ifNotOwner
					permissionCode += permissionCode;
				}
				
				final int ownerPermissionIndexStart = 0;
				final int ownerPermissionIndexEnd = permissionCode.charAt(ownerPermissionIndexStart) == '-' ? 
								ownerPermissionIndexStart + 2 : ownerPermissionIndexStart + 1;
				final int notOwnerPermissionIndexStart = ownerPermissionIndexEnd;
				final int notOwnerPermissionIndexEnd = permissionCode.charAt(notOwnerPermissionIndexStart) == '-' ? 
						notOwnerPermissionIndexStart + 2 : notOwnerPermissionIndexStart + 1;
				final String ownerPermissionCode = permissionCode.substring(ownerPermissionIndexStart, ownerPermissionIndexEnd);
				final String notOwnerPermissionCode = permissionCode.substring(notOwnerPermissionIndexStart, notOwnerPermissionIndexEnd);
				ownerPermission = UserAppliedPermission.getPermission(ownerPermissionCode, defaultPermission);
				notOwnerPermission = UserAppliedPermission.getPermission(notOwnerPermissionCode, defaultPermission);
			}
		}
	}

	public PermissionPair(UserAppliedPermission ownerPermission, UserAppliedPermission notOwnerPermission) {
		this.ownerPermission = ownerPermission;
		this.notOwnerPermission = notOwnerPermission;
	}

	public PermissionPair(UserAppliedPermission ownerPermissionForBoth) {
		this(ownerPermissionForBoth, ownerPermissionForBoth);
	}

	public PermissionPair(PermissionPair pp) {
		ownerPermission = pp.ownerPermission;
		notOwnerPermission = pp.notOwnerPermission;
	}

	public UserAppliedPermission getPermission(String ownerOfItem) {

		if (UserSettings.UserName.get().equals(ownerOfItem)) {
			return ownerPermission;
		} else {
			return notOwnerPermission;
		}
	}

	/**
	 * Converts the given Expeditee permission code into a PermissionPair
	 * corresponding to the constants defined in Item.
	 * 
	 * @param permissionCode
	 *            The Expeditee permission code to convert
	 * @return The resulting PermissionPair corresponding to a pair of constants as
	 *         defined in Item
	 */
	public static PermissionPair convertString(String permissionCode) {
		PermissionPair pp = new PermissionPair(permissionCode, UserAppliedPermission.full);

		return pp;
	}

	public String getCode() {
		return Integer.toString(ownerPermission.getCode()) + Integer.toString(notOwnerPermission.getCode());
	}

	@Override
	public String toString() {
		return ownerPermission.toString() + ":" + notOwnerPermission.toString();
	}
}