/*
    * Copyright (C) 2007 ETH Zurich
    *
    * This file is part of Fosstrak (www.fosstrak.org).
    *
    * Fosstrak is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License version 2.1, as published by the Free Software Foundation.
    *
   * Fosstrak 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with Fosstrak; if not, write to the Free
   * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   * Boston, MA  02110-1301  USA
   */
  
  package org.fosstrak.capturingapp.util;
  
  import java.util.LinkedList;
  import java.util.List;
  
  import org.fosstrak.ale.xsd.ale.epcglobal.ECReaderStat;
  import org.fosstrak.ale.xsd.ale.epcglobal.ECReport;
  import org.fosstrak.ale.xsd.ale.epcglobal.ECReportGroup;
  import org.fosstrak.ale.xsd.ale.epcglobal.ECReportGroupListMember;
  import org.fosstrak.ale.xsd.ale.epcglobal.ECReports;
  import org.fosstrak.ale.xsd.ale.epcglobal.ECTagStat;
  import org.fosstrak.ale.xsd.epcglobal.EPC;
  
  /**
   * helper class to perform transformations on ECReports.
   * @author sawielan
   *
   */
  public class Util {
  	
  	/**
  	 * Simple interface that allows you to select an EPC programmatically 
  	 *  (eg. raw-hex, tag, ...);
  	 * @author sawielan
  	 *
  	 */
  	public interface EPCSelector {
  		public EPC select(ECReportGroupListMember member);
  	}
  	
  	/** selector that returns the raw hex. */
  	public static final  EPCSelector selectRawHex  = new EPCSelector() {
  		public EPC select(ECReportGroupListMember member) {
  			return member.getRawHex();
  		}
  	};
  	
  	/** selector that returns the raw decimal. */
  	public static final  EPCSelector selectRawDecimal  = new EPCSelector() {
  		public EPC select(ECReportGroupListMember member) {
  			return member.getRawDecimal();
  		}
  	};
  	
  	/** selector that returns the tag. */
  	public static final  EPCSelector selectTag  = new EPCSelector() {
  		public EPC select(ECReportGroupListMember member) {
  			return member.getTag();
  		}
  	};
  	
  	/** selector that returns the epc . */
  	public static final  EPCSelector selectEPC  = new EPCSelector() {
  		public EPC select(ECReportGroupListMember member) {
  			return member.getEpc();
  		}
  	};
  	
  	/** the default selector. */
  	public static final EPCSelector DEFAULT_SELECTOR = selectRawHex;
  	
  	/**
  	 * checks if a member was retrieved by a given reader.
  	 * @param readerName the name of the reader to check.
  	 * @param member the member to inspect.
  	 * @return true if read from the reader, false otherwise.
  	 */
  	public static boolean fromReader(String readerName, ECReportGroupListMember member) {
  		try {
  			for (ECTagStat stat : member.getExtension().getStats().getStat()) {
  				for (ECReaderStat rstat : stat.getStatBlocks().getStatBlock()) {
  					if (rstat.getReaderName().equals(readerName)) {
  						return true;
  					}
  				}
  			}
  		} catch (Exception e) {
  			return false;
  		}
 		return false;
 	}
 	
 	/**
 	 * extracts all the members containing the EPCs from the reports.
 	 * @param reports the report to "digest". 
 	 * @return a list of members providing access to the EPC data.
 	 */
 	public static List<ECReportGroupListMember> extractReportMembers(ECReports reports) {
 		List<ECReportGroupListMember> members = 
 			new LinkedList<ECReportGroupListMember> ();
 			
 		if (null == reports) return members;
 		if (null == reports.getReports()) return members;
 		for (ECReport report : reports.getReports().getReport()) {
 			members.addAll(extractReportMembers(report));
 		}
 		return members;
 	}
 	
 	/**
 	 * extracts all the members containing the EPCs from the report.
 	 * @param report the report to "digest". 
 	 * @return a list of members providing access to the EPC data.
 	 */
 	public static List<ECReportGroupListMember> extractReportMembers(ECReport report) {
 		List<ECReportGroupListMember> members = 
 			new LinkedList<ECReportGroupListMember> ();
 			
 		if (null == report) return members;
 		if (null == report.getGroup()) return members;
 		for (ECReportGroup group : report.getGroup()) {
 			if ((null != group) && (null != group.getGroupList()) && 
 					(null != group.getGroupList().getMember())){
 						
 				for (ECReportGroupListMember member : group.getGroupList().getMember()) {
 					members.add(member);
 				}
 			}
 		}
 		
 		return members;
 	}
 	
 	/**
 	 * extracts EPC values from the reports. when the selector is set to 
 	 * <code>null</code>, then the default selector will be chosen.
 	 * @param selector the selector selecting the matching EPCs.
 	 * @param reports the reports from where to select the EPCs.
 	 * @return returns a list of selected EPCs. 
 	 */
 	public static List<EPC> extractEPC(EPCSelector selector, ECReports reports) {
 		List<EPC> epcs = new LinkedList<EPC> ();
 		if (null == reports.getReports()) return epcs;
 		for (ECReport report : reports.getReports().getReport()) {
 			epcs.addAll(extractEPC(selector, report));
 		}
 		return epcs;
 	}
 	
 	/**
 	 * extracts EPC values from the report. when the selector is set to 
 	 * <code>null</code>, then the default selector will be chosen.
 	 * @param selector the selector selecting the matching EPCs.
 	 * @param report the report from where to select the EPCs.
 	 * @return returns a list of selected EPCs.
 	 */
 	public static List<EPC> extractEPC(EPCSelector selector, ECReport report) {
 		List<EPC> epcs = new LinkedList<EPC> ();
 		for (ECReportGroupListMember member : extractReportMembers(report)) {
 			EPCSelector s = selector;
 			if (null == selector) s = DEFAULT_SELECTOR;
 			
 			EPC epc = s.select(member);			
 			if (null != epc) epcs.add(epc);
 		}
 		return epcs;
 	}
 	
 	/**
 	 * helper to prepare a nice pretty print of a whole ECReport.
 	 * @param report the ECReport to print.
 	 * @return a nice pretty print.
 	 */
 	public static String printReport(ECReport report) {
 		StringBuffer buffer = new StringBuffer(String.format("name: %n", 
 				report.getReportName()));
 		if (null != report.getGroup()) {
 			for (ECReportGroup group : report.getGroup()) {
 				if (null != group.getGroupList()) {
 					for (ECReportGroupListMember member : group.getGroupList().getMember()) {
 						buffer.append(printGroupMember(member));
 					}
 				}
 			}
 		}
 		return buffer.toString();
 	}
 	
 	/**
 	 * helper to prepare a nice pretty print of a group member of a ECReport.
 	 * @param member the member to print.
 	 * @return a nice pretty print.
 	 */
 	public static String printGroupMember(ECReportGroupListMember member) {
 		StringBuffer b = new StringBuffer();
 		if (null != member.getEpc()) {
 			b.append(String.format("epc: %s\n", member.getEpc().getValue()));
 		}
 		if (null != member.getTag()) {
 			b.append(String.format("tag: %s\n", member.getTag().getValue()));
 		}
 		if (null != member.getRawDecimal()) {
 			b.append(String.format("decimal: %s\n", member.getRawDecimal()
 					.getValue()));
 		}
 		if (null != member.getRawHex()) {
 			b.append(String.format("hex: %s\n", member.getRawHex().getValue()));
 		}
 		b.append("\n");
 
 		return b.toString();
 	}
 }