/* -*-Java-*-

********************************************************************************

*

* File:         CollectionPlug.java

* RCS:          $Header: /u/testbed/CVSROOT/dldev/doc/Visigenic/InfoBus/StreetRouterProxy/CollectionPlug.Google,v 1.1 1998/05/19 23:23:29 paepcke Exp $

* Description:  Mediates Between InfoBus Protocol Engine and Service Interface

* Author:       Gerard Rodriguez, Stanford University

* Created:      Wed Jan 15 10:10:21 1998

* Modified:     Thu Apr 16 13:13:19 1998 (Andreas Paepcke) paepcke@SNUGGLES

* Language:     Java

* Package:      N/A

* Status:       Experimental (Do Not Distribute)

*

* (c) Copyright 1998, Stanford University, all rights reserved.

*

********************************************************************************

*

* Revisions:

*

* Wed Apr 15 10:11:17 1998 (Andreas Paepcke) paepcke@SNUGGLES

*  Rewrote to match our new, cleaned-up specification.

********************************************************************************

*/



/**

CollectionPlug mediates between the DLIOP protocol engine

(DLIOPwrapper.java), and StreetRouterServer, which knows how to

interact with the street router program MapQuest via the Web.  The

methods in this class are called by the DLIOPwrapper. The collection

plug establishes a connection with MapQuest, submits queries,

stores the results, and returns them to DLIOPWrapper as requested.

<p>

Note that this street routing example is somewhat degenerate, because

the result of each search (i.e. each request for a route) always

returns a single result, namely the string with the driving directions.

So some of the features, such as sequential access to subsequent

documents in a result set that normally would be used in a collection

plug are not really exercised in this example. However, we have 

included the corresponding code anyway (loops that only run for one

iteration, etc.), so this should still work well as an example.

<p>

Further documentation: About DLIOP, see 

   http://www-diglib.stanford.edu/cgi-bin/WP/get/SIDL-WP-1997-0054

For an explanation of what collection plugs do, see: ****

*/



import java.io.*;

import java.awt.*;

import java.net.*;

import java.lang.*;



public class CollectionPlug {



  private String TheQuery;

  private static final int MAX_RESULTS = 100;
  private GeneralDoc[] objects = new GeneralDoc[MAX_RESULTS];

  private int numDocs;  // number of docs found as result of a search

  private int theDocCursor; // next new doc to hand to the wrapper if he asks

  private int docs_stored; //num of docs pulled from service and cached here.

  private boolean flagmore;


  //The names we choose for properties is important. Right now, in order to

  //make this proxy compatible with the rest of services in InfoBus, the

  //name of each property should be included in the USMarc.java file. This

  //is because the InfoBus uses a derivative of USMARC as a lingua franca.

  private static String[] supportedProps = new String[3];

  private String[] requestedProps = new String[supportedProps.length];


  // header and tail for the url
  private String url_header = "http://z.stanford.edu:4200/web.fcg?searchterm=";
  private String url_tail = "&ranking=on&num=";
  private String url_tail2 = "&cluster=1";
  private String add_url_object = "http://z.stanford.edu:4200";


  // Class constructor

  public CollectionPlug () {



    supportedProps[0] = "title";

    supportedProps[1] = "url";
    supportedProps[2] = "weight";
    TheQuery = "";

    numDocs = 0;

    theDocCursor = 0;

    flagmore = false;
    return;

  }



  // SetProperties(props)

  // props : list of the names of properties the caller wants

  // included in every returned document. This list must be a subset 

  // of the list of properties supported by this CollectionPlug. If

  // the list is empty, all properties are wanted:



  public void SetProperties (String[] props) 

      throws java.lang.IllegalArgumentException {



    System.out.println("SetProperties (String[] propos)");
    for(int jj =0;jj<props.length;jj++)
      System.out.println(props[jj]);

    int aux;

    if (props.length == 0) {

      //An empty list means all the properties:

      for(int i=0;i<supportedProps.length;i++) {

        requestedProps[i] = supportedProps[i];

      }

      return;

    }

    // Remember which props we are to return w/ each document:

    // This makes a new array each time, with the assumption that this

    // method won't be called much. If it is, you could null out the 

    // existing array and reuse it:

    requestedProps = new String[props.length];

    for(int i=0;i<props.length;i++) {

      if (!CheckPropAvailability(props[i])) 

        throw new IllegalArgumentException();

      requestedProps[i] = props[i];

    }

    return;

  }



  // GetDefaultPropertyNames()

  // Returns the default set of names of the supported set of properties in the 

  // documents of this CollectionPlug.



  public String[] GetDefaultPropertyNames() {

    System.out.println("GetDefaultPropertyNames() ");
    return(supportedProps);

  }



  // GetPropertyNames(int IndexDocument)

  // Returns the name of the default set of properties in that particular

  // document



  public String[] GetPropertyNames(int index) {

    // In this example, all the documents in a CollectionPlug have the same

    // set of properties. So, we ignore the index of the document, and

    // call the GetProperties method.



    System.out.println("GetPropertyNames(int index)");

    return(this.GetPropertyNames());

  }



  // GetPropertyNames()

  // Returns the names of the properties that were previously set in a

  // call to SetProperties:



  public String[] GetPropertyNames() {

    System.out.println("GetPropertyNames()");
    for(int i=0;i<requestedProps.length;i++)
      System.out.println(requestedProps[i]);
    return requestedProps;

  }



  public int Search(String query, int maxhits) throws Exception {

    // In this example,

    // query is a list of keywords separated by spaces

    // maxhits is how many hits are to be fetched initially



    // Extract the parametres from the single query string and

    // store them into several variables:


    System.out.println("Search");


    this.TheQuery = query;

    // Setting the url
    String url = url_header;
    url = url.concat(query.replace(' ','+'));
    url = url.concat(url_tail);
    url = url.concat(String.valueOf(maxhits));
    url = url.concat(url_tail2);
    System.out.println("\n Sending URL :\n" + url);




    this.docs_stored = SendQuery(url,maxhits);



    this.theDocCursor = 0;

    if (this.numDocs > maxhits)
        return(maxhits);
    return(this.numDocs);

  }



  // GetPropertyValues (pointer)

  // The 'pointer' is a pointer to the array of documents found by

  // a previous search. This method returns the value of all the

  // document's properties.



  public String[] GetPropertyValues (int p)

       throws java.lang.ArrayIndexOutOfBoundsException {



    System.out.println("GetPropertyValues(int p)" + p);


    if (p > this.docs_stored) throw new ArrayIndexOutOfBoundsException();

    String[] aux = new String[requestedProps.length];



    for(int i=0;i<requestedProps.length;i++) {
      System.out.println(requestedProps[i]);
      aux[i] = objects[p].Get_prop(requestedProps[i]);
    }


    // One more doc was passed up to the wrapper:

    theDocCursor++;

    return aux;

  }



  // GetPropertyValues (pointer, list of property names)

  // The 'pointer' is a pointer to the array of documents found by

  // Search.

  // This method returns the value of the properties in the list

  // of property names for the document identified by the pointer.



  public String[] GetPropertyValues (int p, String[] propnames)       

     throws java.lang.ArrayIndexOutOfBoundsException, 

            java.lang.IllegalArgumentException {



    //In this example there is only one document in the CollectionPlug

    //since the service only gives us a single string, and we only have

    //one property.


    System.out.println("GetPropertyValues(int p, String[] propnames)");

   
    if (p > this.docs_stored) throw new ArrayIndexOutOfBoundsException();

    if (!CheckPropAvailability(propnames)) 

      throw new ArrayIndexOutOfBoundsException();



    String[] aux = new String[propnames.length];



    for(int i=0;i<propnames.length;i++) {
      aux[i] = objects[p].Get_prop(propnames[i]);
    }


    // One more doc was passed up to the wrapper:

    theDocCursor++;

    return aux;



  }



  public int TotalItems() {


    System.out.println("TotalItems");

    return numDocs;

  }


  public String TheQuery() {
    return TheQuery;
  }



  // Return true if we were not yet asked for all the docs:

  public boolean MoreAvailable() {


    System.out.println("MoreAvailable()");
    
    if ((numDocs > 0) && (theDocCursor < numDocs)) return true;
    else return false;

  }



  public int DocCursor () {


    System.out.println("DocCursor()");
    
    return theDocCursor;

  }





  // CheckPropAvailability (list of property names)

  // Returns true if each property in a list of property names is 

  // supported by this CollectionPlug.



  public static boolean CheckPropAvailability (String[] propList) {


    System.out.println("CheckPropAvailability(String[])");
    
    for (int i=0; i<propList.length; i++)

      if (!CheckPropAvailability(propList[i])) return false;

    return true;

  }



  // CheckPropAvailability(String propName) returns true if that property

  // is supported:



  public static boolean CheckPropAvailability(String propName) {


    System.out.println("CheckPropAvailability(String)" + propName);
    
    for (int i=0; i<supportedProps.length; i++)

      if (supportedProps[i].equalsIgnoreCase(propName)) return true;

    return false;

  }


  // Local procedures

  private int SendQuery (String url, int maxhist) throws Exception {

        Object content;
        String result;
        URLConnection mycon;
        int counter = 0;

            URL myURL = new URL(url);
            mycon = myURL.openConnection();
            
                mycon.connect();
                DataInputStream dis = new DataInputStream(mycon.getInputStream());
                String line = dis.readLine();
                short j = -1;
        
        while (line.indexOf("<i>Copyright &copy;") == -1) {
          //System.out.println("j=" + j);          
          //System.out.println(line);
          if (j==-3) {
            //We have found docs....
            //Getting docs one by one and storing them in tdocs
            objects[counter++] = GetDoc(line);
          }
          if (j==-1) {
            //Getting number of docs found
            this.numDocs = getTotalDocs(line);
            if (this.numDocs != -1) {
              //There are docs
              j = -3;
              counter = 0;
            }
          }
          line = dis.readLine();
        }

                System.out.println("Total docs found:" + this.numDocs);
                System.out.println("Docs found by the parser: " + counter);
		    
                if (this.numDocs > counter) {
                  // This means we have a parser problem and we are not
                  // able to get all the docs, or the connection went down
                  // just in the middle of the transmission
                  // So, we set the flag to: yet more docs to come
                  this.flagmore = true;
                }
                return(counter);
  }

  private GeneralDoc GetDoc(String line) throws Exception {
  //Gets the document and all its fields in a Doc object            
  GeneralDoc object = new GeneralDoc();
  int index = -1;
  String aux;
  String ltitle;
  String lurl;
  String lweight;

  index = line.indexOf("<p><a href=");
  if ( index != -1) {
    int index2 = line.indexOf("\">");
    try {
      lurl = line.substring(index + 12, index2);
      index = line.indexOf("</a>");
      ltitle = line.substring(index2 + 2, index);
      lweight = line.substring(line.indexOf("<font color=red>") + 16,
                               line.indexOf("%</font>"));
    }
    catch (Exception e) {
      System.out.println("Error parsing the line" + e);
      return object;
    }
  } else {
    return object;
  }



  String[] values = new String[3];
  values[0] = ltitle;
  values[1] = lurl;
  values[2] = lweight;
  object = new GeneralDoc(this.supportedProps, values);
  System.out.println("The Object is: " + object.toString());
  return object;
}

private int getTotalDocs(String line) {
        int index = -1;
        String aux = "";
        
        index = line.indexOf("<br><br>Displaying");
        if ( index == 0) {
            //We've got the line where the number documents is
            try {
                //System.out.println("Index of documents: " + index);
                index = line.indexOf(" ");
                int index2 = line.lastIndexOf(" ");
                aux = line.substring(index + 1, index2);
                //System.out.println(aux);
            }
            catch (Exception e) {
                System.out.println("Error parsing the line" + e);
                return -1;
            }
            return (Integer.valueOf(aux).intValue());
        }
        return -1;
}

}