<?php
  /**********************************************************
   Copyright (c) 2010 Wayne State University Library System
 
   Licensed under the MIT License
   Redistributions of files must retain the above copyright notice.
   
   FILE:         	  index.php
   TITLE:             Mapping System Main Page
   ORIGINAL AUTHOR:   Paul Gallagher, WSULS Developer Librarian
   CONTACT:           paul.gallagher@wayne.edu
   CREATED:           August 2009
   
   PURPOSE:
   This file holds the base logic to determine if a request is 
   from the catalog, or is headed to the reference form, and 
   conducts the data harvesting from the Millennium system XML
   server.  It also triggers the map_select.php page (if needed).
   ***********************************************************/

  
  
  //#####################  Page Logic  #############################
  //Pull in GET parameters
  $clean = array();
  foreach ($_GET as $key => $value) {
      $clean[$key] = $value;
  }
  
  $xoclc = $clean['oclc'];
  $type = $clean['type'];
  
  //Get the III record number from XML
  $fname = "http://elibrary.wayne.edu/xmlopac/o$xoclc/1/1/1/10?link=i1-2&nodtd=y&noexclude=WXROOT.Heading.Title.IIIRECORD";
  $brec = getXMLData('//RECORDKEY', $fname);
  
  //Check if the link is from the catalog or is headed to the reference form, based on a type=1 parameter (which only the catalog has)
  if ($type == 1) {
      //check for number of copies
      $nc = GetScreenScrapeCountUnique($brec);
      
      //perform a switch based on the number of copies
      switch ($nc) {
          case ($nc == 1):			//one record, show map directly
              //Get the location
              $loc = GetScreenScrapeLocation($brec);
              //Get the call number  
              $call = GetScreenScrapeCall($brec);
              //Get the map code
              $mapId = GetMapCode($loc);
              
              //redirect the page to map_display, passing the mapId and call number
              header('Location: map_display.php?mapId=' . $mapId . '~' . $call);
              break;
              
          case ($nc > 1):
              //more than one record, show selector, has location        
              include('map_select.php');
              break;
              
          case ($nc == 0):
              //no record count, redirect to reference.php (error) page - this should not happen
              header('Location: reference.php');
      }
  } else {
	  //redirects to reference form if the type is blank
      header('Location: map_callnumber.php');
  }
  
  
  //#####################  Functions  #############################
  function getXMLData($query, $xmlDocument)
  {
      //setup DomDocument
      $xp = createDomDoc($xmlDocument);
      //do the xpath query
      $nodes = $xp->query("$query");
      //return the node value
      foreach ($nodes as $node) {
          $n = $node->textContent;
      }
      //return string with element value
      return $n;
  }
  
  function createDomDoc($xmlDocument, $reset = false)
  {
      static $x;
      
      if (!isset($x) || $reset) {
          $dom = new DomDocument();
          $dom->load($xmlDocument);
          $x = new domxpath($dom);
      }
      
      return $x;
  }
?>